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Tuesday, December 26, 2023

Whistleblowing

From Wikipedia, the free encyclopedia

Whistleblowing (also ‘whistle-blowing’ or ‘whistle blowing’) is the activity of a person, often an employee, revealing information about activity within a private or public organization that is deemed illegal, immoral, illicit, unsafe or fraudulent. Whistleblowers can use a variety of internal or external channels to communicate information or allegations. Over 83% of whistleblowers report internally to a supervisor, human resources, compliance, or a neutral third party within the company, hoping that the company will address and correct the issues. A whistleblower can also bring allegations to light by communicating with external entities, such as the media, government, or law enforcement. Some countries legislate as to what constitutes a protected disclosure, and the permissible methods of presenting a disclosure. Whistleblowing can occur in the private sector or the public sector.

Whistleblowers often face retaliation for their disclosure including termination of employment. Several other actions may also be considered retaliatory, including unreasonable increase in workloads, reduction of hours, preventing task completion, mobbing or bullying. Laws in many countries attempt to provide protection for whistleblowers and to regulate whistleblowing activities. These laws tend to adopt different approaches to public and private sector whistleblowing.

Whistleblowers do not always achieve their aims; for their claims to be credible and successful, they must have compelling evidence to support their claims so that the government or regulating body can investigate such claims and hold corrupt companies and/or government agencies to account.

Overview

Origin of term

U.S. civic activist Ralph Nader is said to have coined the phrase in the early 1970s in order to avoid the negative connotations found in other words such as "informer" and "snitch". However, the origins of the word date back to the 19th century.

The word is linked to the use of a whistle to alert the public or a crowd about such problems as the commission of a crime or the breaking of rules during a game. The phrase whistle blower attached itself to law enforcement officials in the 19th century because they used a whistle to alert the public or fellow police. Sports referees, who use a whistle to indicate an illegal or foul play, also were called whistle blowers.

An 1883 story in the Janesville Gazette called a policeman who used his whistle to alert citizens about a riot a whistle blower, without the hyphen. By the year 1963, the phrase had become a hyphenated word, whistle-blower. The word began to be used by journalists in the 1960s for people who revealed wrongdoing, such as Nader. It eventually evolved into the compound word whistleblower.

Channels for whistleblowing

Internal channels

Most whistleblowers are internal whistleblowers, who report misconduct on a fellow employee or superior within their company through anonymous reporting mechanisms often called hotlines. Within such situations, circumstances and factors can cause a person to either act on the spot to prevent/stop illegal and unacceptable behavior, or report it. There are some reasons to believe that people are more likely to take action with respect to unacceptable behavior, within an organization, if there are complaint systems that offer not just options dictated by the planning and control organization, but a choice of options for absolute confidentiality.

Anonymous reporting mechanisms, as mentioned previously, help foster a climate whereby employees are more likely to report or seek guidance regarding potential or actual wrongdoing without fear of retaliation. The coming anti-bribery management systems standard, ISO 37001, includes anonymous reporting as one of the criteria for the new standard.

External channels

External whistleblowers report misconduct to outside people or entities. In these cases, depending on the nature of the information, whistleblowers may report the misconduct to lawyers, the media, law enforcement or watchdog agencies, or other local, state, or federal agencies. In some cases, external whistleblowing is encouraged by offering monetary rewards.

Third party channels

Sometimes organizations use external agencies to create a secure and anonymous reporting channel for its employees, often referred to as a whistleblowing hotline. As well as protecting the identity of the whistleblower, these services are designed to inform the individuals at the top of the organizational pyramid of misconduct, usually via integration with specialised case management software.

Implementing a third party solution is often the easiest way for an organization to promote compliance, or to offer a whistleblowing policy where one did not previously exist. An increasing number of companies and authorities use third party services in which the whistleblower is anonymous also towards the third party service provider, which is made possible via toll free phone numbers and/or web or app-based solutions which apply asymmetrical encryption.

Private versus public sectors

Private sector whistleblowing

Private sector whistleblowing is arguably more prevalent and suppressed in society today. An example of private sector whistleblowing is when an employee reports to someone in a higher position such as a manager, or to external factors, such as their lawyer or the police. Whistleblowing in the private sector is typically not high-profile or openly discussed in major news outlets, though occasionally, third parties expose human rights violations and exploitation of workers.

Many governments attempt to protect such whistleblowers. In the United States, for example, there are organizations such as the United States Department of Labor (DOL), and laws such as the Sarbanes-Oxley Act and the United States Federal Sentencing Guidelines for Organizations (FSGO) that protect whistleblowers in the private sector. Thus, despite government efforts to help regulate the private sector, the employees must still weigh their options. They either expose the company and stand the moral and ethical high ground; or expose the company, lose their job, their reputation and potentially the ability to be employed again. According to a study at the University of Pennsylvania, out of three hundred whistleblowers studied, sixty nine percent of them had foregone that exact situation; and they were either fired or were forced to retire after taking the ethical high ground. It is outcomes like that which makes it all that much harder to accurately track how prevalent whistleblowing is in the private sector.

Public sector whistleblowing

Czech whistleblower Libor Michálek was fired from his position after exposing high-level corruption.

Recognition of the value of public sector whistleblowing has been growing over the last 50 years. In the United States, for example, both state and Federal statutes have been put in place to protect whistleblowers from retaliation. The United States Supreme Court ruled that public sector whistleblowers are protected from retaliation by their First Amendment rights. After many federal whistleblowers were covered in high-profile media cases, laws were finally introduced to protect government whistleblowers. These laws were enacted to help prevent corruption and encourage people to expose misconduct, illegal, or dishonest activity for the good of society. People who choose to act as whistleblowers often suffer retaliation from their employer. They most likely are fired because they are an at-will employee, which means they can be fired without a reason. There are exceptions in place for whistleblowers who are at-will employees. Even without a statute, numerous decisions encourage and protect whistleblowing on grounds of public policy. Statutes state that an employer shall not take any adverse employment actions any employee in retaliation for a good-faith report of a whistleblowing action or cooperating in any way in an investigation, proceeding, or lawsuit arising under said action. Federal whistleblower legislation includes a statute protecting all government employees. In the federal civil service, the government is prohibited from taking, or threatening to take, any personnel action against an employee because the employee disclosed information that they reasonably believed showed a violation of law, gross mismanagement, and gross waste of funds, abuse of authority, or a substantial and specific danger to public safety or health. To prevail on a claim, a federal employee must show that a protected disclosure was made, that the accused official knew of the disclosure, that retaliation resulted, and that there was a genuine connection between the retaliation and the employee's action.

Whistleblowing in the scientific community

Research fraud involves data, processes, or observations that were never there to begin with or later added on to fit a claim or narrative. A case involving the scientific community engaging in research fraudulence is that of Dr. Cyril Burt. Dr Cyril Burt was a British psychologist who proposed that he had discovered a heritable factor for intelligence based on studying twins. Dr. Oliver Gillie, a former colleague of Dr. Burt, inquired about Dr. Burt’s work, doubting the authenticity of the data and the certain twins that Dr. Burt was basing his research on. Dr. Gillies's inquiry revealed that there were discrepancies to Dr. Burt’s work with inconsistencies in the twin's birth dates  particularly with the absence of records for twins to participate in the study, the falsification of data, and the “invention of crucial facts to support his controversial theory that intelligence is largely inherited.”  This led to the eventual retraction of Dr. Burt’s work.

Data manipulation is the changing or omitting of data or outcomes in such a way that the research is not accurately portrayed in the research record. Dr. Hwang Woo-Suk, a South Korean stem cell researcher gained international recognition for his groundbreaking work on cloning and stem cell research. Dr. Woo-Suk had a claim to successfully clone human embryos and derived patient-specific stem cell lines, forwarding the field of regenerative medicine which was published in the Journal of Science. Dr. Kim Seon-Jung expressed his concerns regarding the accuracy of the research data and the ethical conduct of the experiments. Independent committees, as well as journalists, scrutinized the research data and methodology leading to an eventual retraction of his work.

Ethical violations can fall under the following: altering or making up new data to meet a specific goal, adjusting how data is shown or explained, looking at data in a biased manner, and leaving out parts about data analysis and conclusions. Dr. Paolo Macchiarini is well-known within the scientific community as a thoracic surgeon and former regenerative researcher. Dr Macchiarini claimed to have made profound advancements in trachea transplantation by using synthetic tracheal scaffolds planted with the patient’s own stem cells. The goal was that the stem cells would eventually provide the patient with a suitable replacement trachea. Dr. Karl-Henrik Grinnemo, a member of Dr. Machiarini’s research team, raised concerns about the accuracy of the reported results and the ethical conduct of the experiments. Dr. Macchiarini’s ethical violations include exaggeration of success, failure to disclose the adverse post-operational effects, and complications of the surgery. Patients experienced severe health problems; several died post-surgery. The acts of Dr. Macchiarini led to the retractions of research articles from the Lancet, the termination of his academic positions, and criminal inquiries in Sweden. It also sparked concerns over the supervision and control of clinical trials utilizing experimental techniques.

Risks

Individual harm, damage to public trust, and threats to national security are three categories of harm that may come as a result of whistleblowing. Revealing a whistleblower's identity can automatically put their life in danger. Some media outlets associate words like "traitor" and "treason" with whistleblowers, and in many countries around the world, the punishment for treason is the death penalty, even if whoever allegedly committed treason may not have caused anyone physical harm. In some instances, whistleblowers must flee their country to avoid public scrutiny, threats of death or physical harm, and in some cases criminal charges.

Whistleblowers are often protected under law from employer retaliation, but in many cases punishment has occurred, such as termination, suspension, demotion, wage garnishment, and/or harsh mistreatment by other employees. A 2009 study found that up to 38% of whistleblowers experienced professional retaliation in some form, including wrongful termination. Following dismissal, whistleblowers may struggle to find employment due to damaged reputations, poor references and blacklisting. The socioeconomic impact of whistleblowing through loss of livelihood and family strain may also impact on whistleblowers' psychological well being. Whistleblowers often experience immense stress as a result of litigation regarding harms such as unfair dismissal, which they often face with little or no support from unions. Whistleblowers who continue to pursue their concerns may also face long battles with official bodies such as regulators and government departments. Such bodies may reproduce the "institutional silence" adopted by employers, adding to whistleblowers' stress and difficulties. Thus, whistleblowers often suffer great injustice that is never acknowledged or rectified.

In a few cases, however, harm is done by the whistleblower to innocent people. Whistleblowers can make unintentional mistakes, and investigations can be tainted by the fear of negative publicity. An example occurred in the Canadian health ministry, when a new employee wrongly concluded that nearly every research contract she saw in 2012 involved malfeasance. The end result was the sudden firing of seven people, false and public threats of a criminal investigation, and the death of one researcher by suicide. The government ultimately paid the victims millions of dollars for lost pay, slander, and other harms, in addition to CA $2.41 million spent on the subsequent 2015 investigation into the false charges.

Attitudes toward whistleblowers

Mordechai Vanunu spent 18 years in prison, including more than 11 in solitary confinement.

Whistleblowers are seen by some as selfless martyrs for public interest and organizational accountability]; others view them as "traitors" or "defectors". Some even accuse them of solely pursuing personal glory and fame, or view their behavior as motivated by greed in qui tam cases. Culturally it still has connotations of betrayal, from 'snitching' at one level to 'denunciations' at the other. Speaking out is difficult, especially in a culture where this is not promoted or even actively discouraged. Some academics (such as Thomas Faunce) feel that whistleblowers should at least be entitled to a rebuttable presumption that they are attempting to apply ethical principles in the face of obstacles and that whistleblowing would be more respected in governance systems if it had a firmer academic basis in virtue ethics.

It is likely that many people do not even consider whistleblowing not only because of fear of retaliation but also because of fear of losing relationships both at and outside work.

Persecution of whistleblowers has become a serious issue in many parts of the world:

Employees in academia, business or government might become aware of serious risks to health and the environment, but internal policies might pose threats of retaliation to those who report these early warnings. Private company employees in particular might be at risk of being fired, demoted, denied raises and so on for bringing environmental risks to the attention of appropriate authorities. Government employees could be at a similar risk for bringing threats to health or the environment to public attention, although perhaps this is less likely.

There are examples of "early warning scientists" being harassed for bringing inconvenient truths about impending harm to the notice of the public and authorities. There have also been cases of young scientists being discouraged from entering controversial scientific fields for fear of harassment.

In order to help whistleblowers, private organizations have formed whistleblower legal defense funds or support groups. Examples include the National Whistleblower Center in the United States, and Whistleblowers UK and Public Concern at Work (PCaW)[39] in the United Kingdom. Depending on the circumstances, it is not uncommon for whistleblowers to be ostracized by their co-workers, discriminated against by future potential employers, or even fired from their organization. This campaign directed at whistleblowers with the goal of eliminating them from the organization is referred to as mobbing. It is an extreme form of workplace bullying wherein the group is set against the targeted individual.

Psychological impact

There is limited research on the psychological impacts of whistle blowing. However, poor experiences with whistleblowing can cause a prolonged and prominent assault upon the well being of the whistleblower. As workers attempt to address concerns, they are often met with a wall of silence and hostility by management or colleagues. Depression is often reported by whistleblowers, and suicidal thoughts may occur in up to about 10%. General deterioration in health and self care has been described. The range of symptomatology shares many of the features of posttraumatic stress disorder, though there is debate about whether the trauma experienced by whistleblowers meets diagnostic thresholds. Increased stress related physical illness has also been described in whistleblowers.

The stresses involved in whistleblowing can be huge and may deter whistleblowing out of fear of failure and reprisals. Some whistleblowers speak of overwhelming and persistent distress, drug and alcohol problems, paranoid behaviour at work, acute anxiety, nightmares, flashbacks and intrusive thoughts. This fear may indeed be justified, because an individual who feels threatened by whistleblowing, may plan the career destruction of the "complainant" by reporting fictitious errors or rumours. This technique, labelled as "gaslighting", is a common approach used by organizations to manage employees who cause difficulty by raising concerns. In extreme cases, this technique involves the organization or manager proposing that the complainant's mental health is unstable. Organizations also often attempt to ostracise and isolate whistleblowers by undermining their concerns by suggesting that these are groundless, carrying out inadequate investigations or by ignoring them altogether. Whistleblowers may also be disciplined, suspended and reported to professional bodies upon manufactured pretexts.

Such extreme experiences of threat and loss inevitably cause severe distress and sometimes mental illness, sometimes lasting for years afterwards. This mistreatment also deters others from coming forward with concerns. Thus, poor practices remain hidden behind a wall of silence, and prevent any organization from experiencing the improvements that may be afforded by intelligent failure. Some whistleblowers who break ranks with their organizations have had their mental stability questioned, such as Adrian Schoolcraft, the NYPD veteran who alleged falsified crime statistics in his department and was forcibly committed to a mental institution. Conversely, the emotional strain of a whistleblower investigation is devastating to the accused's family.

Ethics

Ethics is the set of moral principles that govern a person's or group's behavior. Deeper questions and theories of whistleblowing and why people choose to do so can be studied through an ethical approach. Whistleblowing is a topic of several myths and inaccurate definitions. Leading arguments in the ideological camp, maintain that whistleblowing is the most basic of ethical traits and simply telling the truth to stop illegal harmful activities, or fraud against the government/taxpayers. In the opposite camp, many corporations and corporate or government leaders see whistleblowing as being disloyal for breaching confidentiality, especially in industries that handle sensitive client or patient information. Hundreds of laws grant protection to whistleblowers, but stipulations can easily cloud that protection and leave whistleblowers vulnerable to retaliation, sometimes even threats and physical harm. However, the decision and action has become far more complicated with recent advancements in technology and communication.

The ethical implications of whistleblowing can be negative as well as positive. Some have argued that public sector whistleblowing plays an important role in the democratic process by resolving principal–agent problems. However, sometimes employees may blow the whistle as an act of revenge. Rosemary O'Leary explains this in her short volume on a topic called guerrilla government. "Rather than acting openly, guerrillas often choose to remain "in the closet", moving clandestinely behind the scenes, salmon swimming upstream against the current of power. Over the years, I have learned that the motivations driving guerrillas are diverse. The reasons for acting range from the altruistic (doing the right thing) to the seemingly petty (I was passed over for that promotion). Taken as a whole, their acts are as awe inspiring as saving human lives out of a love of humanity and as trifling as slowing the issuance of a report out of spite or anger." For example, of the more than 1,000 whistleblower complaints that are filed each year with the Pentagon's Inspector General, about 97 percent are not substantiated. It is believed throughout the professional world that an individual is bound to secrecy within their work sector. Discussions of whistleblowing and employee loyalty usually assume that the concept of loyalty is irrelevant to the issue or, more commonly, that whistleblowing involves a moral choice that pits the loyalty that an employee owes an employer against the employee's responsibility to serve the public interest. Robert A. Larmer describes the standard view of whistleblowing in the Journal of Business Ethics by explaining that an employee possesses prima facie (based on the first impression; accepted as correct until proved otherwise) duties of loyalty and confidentiality to their employers and that whistleblowing cannot be justified except on the basis of a higher duty to the public good. It is important to recognize that in any relationship which demands loyalty the relationship works both ways and involves mutual enrichment.

The ethics of Edward Snowden's actions have been widely discussed and debated in news media and academia worldwide. Snowden released classified intelligence to the American people in an attempt to allow Americans to see the inner workings of the government. A person is diligently tasked with the conundrum of choosing to be loyal to the company or to blow the whistle on the company's wrongdoing. Discussions on whistleblowing generally revolve around three topics: attempts to define whistleblowing more precisely, debates about whether and when whistleblowing is permissible, and debates about whether and when one has an obligation to blow the whistle.

Motivations

Many whistleblowers have stated that they were motivated to take action to put an end to unethical practices, after witnessing injustices in their businesses or organizations. A 2009 study found that whistleblowers are often motivated to take action when they notice a sharp decline in ethical practices, as opposed to a gradual worsening. There are generally two metrics by which whistleblowers determine if a practice is unethical. The first metric involves a violation of the organization's bylaws or written ethical policies. These violations allow individuals to concretize and rationalize blowing the whistle. On the other hand, "value-driven" whistleblowers are influenced by their personal codes of ethics. In these cases, whistleblowers have been criticized for being driven by personal biases.

In addition to ethics, social and organizational pressure are a motivating forces. A 2012 study shows that individuals are more likely to blow the whistle when others know about the wrongdoing, because they fear the consequences of keeping silent. In cases where one person is responsible for wrongdoing, the whistleblower may file a formal report, rather than directly confronting the wrongdoer, because confrontation would be more emotionally and psychologically stressful. Furthermore, individuals may be motivated to report unethical behavior when they believe their organizations will support them. Professionals in management roles may feel responsibility to blow the whistle to uphold the values and rules of their organizations.

Legal protection for whistleblowers

Legal protection for whistleblowers varies from country to country and may depend on the country of the original activity, where and how secrets were revealed, and how they eventually became published or publicized. Over a dozen countries have now adopted comprehensive whistleblower protection laws that create mechanisms for reporting wrongdoing and provide legal protections to whistleblowers. Over 50 countries have adopted more limited protections as part of their anti-corruption, freedom of information, or employment laws. For purposes of the English Wikipedia, this section emphasizes the English-speaking world and covers other regimes only insofar as they represent exceptionally greater or lesser protections.

Australia

There are laws in a number of states. The former NSW Police Commissioner Tony Lauer summed up official government and police attitudes as: "Nobody in Australia much likes whistleblowers, particularly in an organization like the police or the government." The former Australian intelligence officer known as Witness K, who provided evidence of Australia's controversial spying operation against the government of East Timor in 2004, face the possibility of jail if convicted.

Whistleblowers Australia is an association for those who have exposed corruption or any form of malpractice, especially if they were then hindered or abused.

Canada

The Public Sector Integrity Commissioner (PSIC) provides a safe and confidential mechanism enabling public servants and the general public to disclose wrongdoings committed in the public sector. It also protects from reprisal public servants who have disclosed wrongdoing and those who have cooperated in investigations. The office's goal is to enhance public confidence in Canada's federal public institutions and in the integrity of public servants.

Mandated by the Public Servants Disclosure Protection Act, PSIC is a permanent and independent agent of Parliament. The act, which came into force in 2007, applies to most of the federal public sector, approximately 400,000 public servants. This includes government departments and agencies, parent Crown corporations, the Royal Canadian Mounted Police and other federal public sector bodies.

Not all disclosures lead to an investigation as the act sets out the jurisdiction of the commissioner and gives the option not to investigate under certain circumstances. On the other hand, if PSIC conducts an investigation and finds no wrongdoing was committed, the commissioner must report his findings to the discloser and to the organization's chief executive. Also, reports of founded wrongdoing are presented before the House of Commons and the Senate in accordance with the act.

The act also established the Public Servants Disclosure Protection Tribunal (PSDPT) to protect public servants by hearing reprisal complaints referred by the Public Sector Integrity Commissioner. The tribunal can grant remedies in favour of complainants and order disciplinary action against persons who take reprisals.

European Union

The European Parliament approved a "Whistleblower Protection Directive" containing broad free speech protections for whistleblowers in both the public and the private sectors, including for journalists, in all member states of the European Union. The Directive prohibits direct or indirect retaliation against employees, current and former, in the public sector and the private sector. The Directive's protections apply to employees, to volunteers, and to those who assist them, including to civil society organizations and to journalists who report on their evidence. In October 2021, the EU Directorate-General for Justice and Consumers, Equality and the Rule of Law emphasized that ministries, as legal entities in the public sector, are also explicitly required to establish internal reporting channels for their employees. It provides equal rights for whistleblowers in the national security sector who challenge denial or removal of their security clearances. Also, whistleblowers are protected from criminal prosecution and corporate lawsuits for damages resulting from their whistleblowing, and provides for psychological support for dealing with harassment stress.

Good government observers have hailed the EU directive as setting "the global standard for best practice rights protecting freedom of speech where it counts the most—challenging abuses of power that betray the public trust," according to the U.S.-based Government Accountability Project. They have noted, however, that ambiguities remain in the Directive regarding application in some areas, such as "duty speech," that is, when employees report the same information in the course of a job assignment, for example, to a supervisor, instead of whistleblowing as formal dissent. In fact, duty speech is how the overwhelming majority of whistleblowing information gets communicated, and where the free flow of information is needed for proper functioning of organizations. However it is in response to such "duty speech" employee communication that the vast majority of retaliation against employees occurs. These observers have noted that the Directive must be understood as applying to protection against retaliation for such duty speech because without such an understanding the Directive will "miss the iceberg of what's needed".

France

In France, several laws, all recent, have established a protection regime for whistleblowers. Prior to 2016, there were several laws in force which created disparate legislation with sector-specific regimes. The 2016 law on transparency, fight against corruption and modernization of economic life (known as the "Sapin 2 Law") provides for the first time a single legal definition of whistleblowers in France. It defines him or her as "an individual who discloses or reports, in a disinterested manner and in good faith, a crime or an offence, a serious and manifest breach of an international commitment duly ratified or approved by France, an unilateral act of an international organization adopted on the basis of such a commitment, of the law or regulations, or a serious threat or harm to general interest, which he or she has become personally aware of." It excludes certain professional secrets such as national defense secrecy, medical secrecy or the secrecy of relations between a lawyer and his client.

In 2022, two laws are passed to transpose the European Directive 2019/1937 of 23 October 2019 on the protection of persons who report breaches of Union law. One of them strengthens the role of the Défenseur des droits - the French ombudsman - tasked with advising and protecting whistleblowers. The second amends the Sapin 2 law to bring it into line with the directive and adds substantial guarantees not included in the directive among which:

  • The definition of whistleblowing in force under the 'Sapin 2' law – which includes not work-based whistleblowing - has been maintained.
  • The protection applies to any natural person who facilitate or assist whistleblowers – as required in the directive – but also to entities such as NGO or trade unions which act as a facilitator. They are offered the same level of protection.
  • Military personnel will now be afforded the same level of protection as other civil servants, so long as they do not disclose information that may harm national security.
  • The law provides that whistleblowers may be granted financial assistance, when subjected to a suit, by making an application to a judge, who has the power to force the organization which is suing – the employer for instance - to provide to cover legal fees and, where relevant, to cover their living expenses where their financial situation has deteriorated.
  • The law provides that whistleblowers shall not incur criminal liability in respect of the acquisition of, or access to, the information which is reported or publicly disclosed. They cannot be sentenced for any offenses committed in order to gather proof or information as long as they obtained it in a lawful manner.
  • The law strengthens existing sanctions against those who retaliate against whistleblowers: the criminal sanctions appliable to persons retaliating against whistleblowers can go up to three years of imprisonment and a fine of 45 000 €. The judges may impose 60 000 € fines on companies who taking a SLAPP action against a whistleblower.

The law allows any person to apply to the Défenseur des droits for an opinion on his or her status as a whistleblower. A response should be given within six months after receiving the application. The organic law provides that the Défenseur des droits will publish a report every two years on the overall functioning of whistleblower protection addressed to the French President of the Republic, the President of the National Assembly and the President of the Senate.

Jamaica

In Jamaica, the Protected Disclosures Act, 2011 received assent in March 2011. It creates a comprehensive system for the protection of whistleblowers in the public and private sector. It is based on the Public Interest Disclosure Act 1998.

India

The Government of India had been considering adopting a whistleblower protection law for several years. In 2003, the Law Commission of India recommended the adoption of the Public Interest Disclosure (Protection of Informers) Act, 2002. In August 2010, the Public Interest Disclosure and Protection of Persons Making the Disclosures Bill, 2010 was introduced into the Lok Sabha, lower house of the Parliament of India. The Bill was approved by the cabinet in June 2011. The Public Interest Disclosure and Protection of Persons Making the Disclosures Bill, 2010 was renamed as The Whistleblowers' Protection Bill, 2011 by the Standing Committee on Personnel, Public Grievances, Law and Justice. The Whistleblowers' Protection Bill, 2011 was passed by the Lok Sabha on 28 December 2011. and by the Rajyasabha on 21 February 2014. The Whistle Blowers Protection Act, 2011 has received the Presidential assent on 9 May 2014 and the same has been subsequently published in the official gazette of the Government of India on 9 May 2014 by the Ministry of Law and Justice, Government of India.

Iran

In 2023 Iranian government made it punishable, illegalized and criminalized whistleblowing publicly, if a whistleblower reveals corruption to authorities but can't prove they will be charged.

Ireland

The government of Ireland committed to adopting a comprehensive whistleblower protection law in January 2012. The Protected Disclosures Act (PDA) was passed in 2014. The law covers workers in the public and private sectors, and also includes contractors, trainees, agency staff, former employees and job seekers. A range of different types of misconduct may be reported under the law, which provides protections for workers from a range of employment actions as well as whistleblowers' identity.

Netherlands

The Netherlands has measures in place to mitigate the risks of whistleblowing: the House for Whistleblowers (Huis voor klokkenluiders) offers advice and support to whistleblowers, and the Parliament passed a proposal in 2016 to establish this house for whistleblowers, to protect them from the severe negative consequences that they might endure (Kamerstuk, 2013). Dutch media organizations also provide whistleblower support; on 9 September 2013 a number of major Dutch media outlets supported the launch of Publeaks, which provides a secure website for people to leak documents to the media. Publeaks is designed to protect whistleblowers. It operates on the GlobaLeaks software developed by the Hermes Center for Transparency and Digital Human Rights, which supports whistleblower-oriented technologies internationally.

Switzerland

The Swiss Council of States agreed on a draft amendment of the Swiss Code of Obligations in September 2014. The draft introduces articles 321abis to 321asepties, 328(3), 336(2)(d). An amendment of article 362(1) adds articles 321abis to 321asepties to the list of provisions that may not be overruled by labour and bargaining agreements.
Article 321ater introduces an obligation on employees to report irregularities to their employer before reporting to an authority. An employee will, however, not breach his duty of good faith if he reports an irregularity to an authority and

  • a period set by the employer and no longer than 60 days has lapsed since the employee has reported the incident to his employer, and
  • the employer has not addressed the irregularity or it is obvious that the employer has insufficiently addressed the irregularity.

Article 321aquarter provides that an employee may exceptionally directly report to an authority. Exceptions apply in cases

  • where the employee is in a position to objectively demonstrate that a report to his employer will prove ineffective,
  • where the employee has to anticipate dismissal,
  • where the employee must assume that the competent authority will be hindered in investigating the irregularity, or
  • where there is a direct and serious hazard to life, to health, to safety, or to the environment.

The draft does not improve on protection against dismissal for employees who report irregularities to their employer. The amendment does not provide for employees anonymously filing their observations of irregularities.

United Kingdom

Whistleblowing in the United Kingdom is protected by the Public Interest Disclosure Act 1998 (PIDA). Amongst other things, under the Act protected disclosures are permitted even if a non-disclosure agreement has been signed between the employer and the former or current employee; a consultation on further restricting confidentiality clauses was held in 2019.

The Freedom to Speak Up Review set out 20 principles to bring about improvements to help whistleblowers in the NHS, including:

  • Culture of raising concerns – to make raising issues a part of normal routine business of a well-led NHS organization.
  • Culture free from bullying – freedom of staff to speak out relies on staff being able to work in a culture which is free from bullying.
  • Training – every member of staff should receive training in their trust's approach to raising concerns and in receiving and acting on them.
  • Support – all NHS trusts should ensure there is a dedicated person to whom concerns can be easily reported and without formality, a "speak up guardian".
  • Support to find alternative employment in the NHS – where a worker who has raised a concern cannot, as a result, continue their role, the NHS should help them seek an alternative job.

Monitor produced a whistleblowing policy in November 2015 that all NHS organizations in England are obliged to follow. It explicitly says that anyone bullying or acting against a whistleblower could be potentially liable to disciplinary action. An observational and interviewed-based study of more than 80 Guardians found that a lack of resources, especially time, reduced their ability to respond to concerns, and to analyse and learn from data. Guardians struggled to develop their role, and create a more positive culture in which staff felt free to voice concerns. Guardians found their role stressful and received little psychological support and as a result many did not intend to stay in their role for long.

United States

Whistleblowing tradition in what would soon become the United States had a start in 1773 with Benjamin Franklin leaking a few letters in the Hutchinson affair. The release of the communications from royal governor Thomas Hutchinson to Thomas Whately led to a firing, a duel and arguably, both through the many general impacts of the leak and its role in convincing Franklin to join the radicals' cause, the taking of another important final step toward the American Revolution.

The first act of the Continental Congress in favor of what later came to be called whistleblowing came in the 1777-8 case of Samuel Shaw and Richard Marven. The two seamen accused Commander in Chief of the Continental Navy Esek Hopkins of torturing British prisoners of war. The Congress dismissed Hopkins and then agreed to cover the defense cost of the pair after Hopkins filed a libel suit against them under which they were imprisoned. Shaw and Marven were subsequently cleared in a jury trial.

To be considered a whistleblower in the United States, most federal whistleblower statutes require that federal employees have reason to believe their employer violated some law, rule, or regulation; testify or commence a legal proceeding on the legally protected matter; or refuse to violate the law.

In cases where whistleblowing on a specified topic is protected by statute, U.S. courts have generally held that such whistleblowers are protected from retaliation. However, a closely divided U.S. Supreme Court decision, Garcetti v. Ceballos (2006) held that the First Amendment free speech guarantees for government employees do not protect disclosures made within the scope of the employees' duties.

In the United States, legal protections vary according to the subject matter of the whistleblowing, and sometimes the state where the case arises. In passing the 2002 Sarbanes–Oxley Act, the Senate Judiciary Committee found that whistleblower protections were dependent on the "patchwork and vagaries" of varying state statutes. Still, a wide variety of federal and state laws protect employees who call attention to violations, help with enforcement proceedings, or refuse to obey unlawful directions. While this patchwork approach has often been criticized, it is also responsible for the United States having more dedicated whistleblowing laws than any other country.

The first US law adopted specifically to protect whistleblowers was the 1863 United States False Claims Act (revised in 1986), which tried to combat fraud by suppliers of the United States government during the American Civil War. The Act encourages whistleblowers by promising them a percentage of the money recovered by the government and by protecting them from employment retaliation.

Another US law that specifically protects whistleblowers is the Lloyd–La Follette Act of 1912. It guaranteed the right of federal employees to furnish information to the United States Congress. The first US environmental law to include an employee protection was the Clean Water Act of 1972. Similar protections were included in subsequent federal environmental laws, including the Safe Drinking Water Act (1974), Resource Conservation and Recovery Act (1976), Toxic Substances Control Act of 1976, Energy Reorganization Act of 1974 (through 1978 amendment to protect nuclear whistleblowers), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, or the Superfund Law) (1980), and the Clean Air Act (1990). Similar employee protections enforced through OSHA are included in the Surface Transportation Assistance Act (1982) to protect truck drivers, the Pipeline Safety Improvement Act (PSIA) of 2002, the Wendell H. Ford Aviation Investment and Reform Act for the 21st Century ("AIR 21"), and the Sarbanes–Oxley Act, enacted on 30 July 2002 (for corporate fraud whistleblowers). More recent laws with some whistleblower protection include the Patient Protection and Affordable Care Act ("ACA", the Consumer Product Safety Improvement Act ("CPSIA"), the Seamans Protection Act as amended by the Coast Guard Authorization Act of 2010 ("SPA"), the Consumer Financial Protection Act ("CFPA"), the FDA Food Safety Modernization Act ("FSMA"), the Moving Ahead for Progress in the 21st Century Act ("MAP-21"), and the Taxpayer First Act ("TFA").

Investigation of retaliation against whistleblowers under 23 federal statutes falls under the jurisdiction of Directorate of Whistleblower Protection Program of the United States Department of Labor's Occupational Safety and Health Administration (OSHA). New whistleblower statutes enacted by Congress, which are to be enforced by the Secretary of Labor, are generally delegated by a Secretary's Order to OSHA's Directorate of Whistleblower Protection Program (DWPP).

The patchwork of laws means that victims of retaliation need to be aware of the laws at issue to determine the deadlines and means for making proper complaints. Some deadlines are as short as 10 days (Arizona State Employees have 10 days to file a "Prohibited Personnel Practice" Complaint before the Arizona State Personnel Board), while others are up to 300 days.

Those who report a false claim against the federal government, and suffer adverse employment actions as a result, may have up to six years (depending on state law) to file a civil suit for remedies under the US False Claims Act (FCA). Under a qui tam provision, the "original source" for the report may be entitled to a percentage of what the government recovers from the offenders. However, the "original source" must also be the first to file a federal civil complaint for recovery of the federal funds fraudulently obtained, and must avoid publicizing the claim of fraud until the US Justice Department decides whether to prosecute the claim itself. Such qui tam lawsuits must be filed under seal, using special procedures to keep the claim from becoming public until the federal government makes its decision on direct prosecution.

American whistleblower Edward Snowden

The Espionage Act of 1917 has been used to prosecute whistleblowers in the United States including Edward Snowden and Chelsea Manning. In 2013, Manning was convicted of violating the Espionage Act and sentenced to 35 years in prison for leaking sensitive military documents to WikiLeaks. The same year, Snowden was charged with violating the Espionage Act for releasing confidential documents belonging to the NSA.

Section 922 of the Dodd–Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank) in the United States incentivizes and protects whistleblowers. By Dodd-Frank, the U.S. Securities and Exchange Commission (SEC) financially rewards whistleblowers for providing original information about violations of federal securities laws that results in sanctions of at least $1M. Additionally, Dodd-Frank offers job security to whistleblowers by illegalizing termination or discrimination due to whistleblowing. The whistleblower provision has proven successful; after the enactment of Dodd-Frank, the SEC charged KBR (company) and BlueLinx Holdings Inc. (company) with violating the whistleblower protection Rule 21F-17 by having employees sign confidentiality agreements that threatened repercussions for discussing internal matters with outside parties. Former President Donald Trump announced plans to dismantle Dodd-Frank in 2016. He created the Office of Accountability and Whistleblower Protection as a part of the Department of Veterans Affairs, which reportedly instead punished whistleblowers.

The US Department of Labor's Whistleblower Protection Program can handle many types of retaliation claims based on legal actions an employee took or was perceived to take in the course of their employment. Moreover, in the United States, if the retaliation occurred due to the perception of who the employee is as a person, the Equal Employment Opportunity Commission may be able to accept a complaint of retaliation. In an effort to overcome those fears, in 2010 Dodd–Frank Wall Street Reform and Consumer Protection Act was put forth to provide great incentive to whistleblowers. For example, if a whistleblower gave information which could be used to legally recover over one million dollars; then they could receive ten to thirty percent of it.

Whistleblowers have risen within the technology industry as it has expanded in recent years. Protection for these specific whistleblowers falls short; they often end up unemployed or worse- in jail. The Dodd-Frank Wall Street Reform and Consumer Protection Act offers an incentive for private sector whistleblowers, but only if they go to the SEC with information. If a whistleblower acts internally, as they often do in the technology industry, they are not protected by the law. Scandals, such as the Dragonfly search engine scandal and the Pompliano lawsuit against snapchat, have drawn attention to whistleblowers in technology.

The federally recognized National Whistleblower Appreciation Day is observed annually on 30 July, on the anniversary of the country's original 1778 whistleblower protection law.

Other countries

In New Zealand, workers are protected by the Protected Disclosures (Protection of Whistleblowers) Act 2022, which went into effect as of 1 July 2022. It replaces the Protected Disclosures Act 2000.

South Africa adopted comprehensive legal protections for whistleblowers with the Protected Disclosures Act of 2000 ('the PDA'). PDA was further strengthened by the passage of an Amendment Act in 2017.

A number of other countries have adopted comprehensive whistleblower laws including Ghana's Whistleblowers Act (Act 720), 2006. South Korea, Uganda, Kenya and Rwanda also have Whistleblower laws. The European Court of Human Rights ruled in 2008 that whistleblowing was protected as freedom of expression.

Nigeria set up a whistleblowing policy against corruption and other ills. Nigeria formulated a Whistleblowing Policy in 2016, but this has not yet been established as law. A new draft bill for Whistle-blower Protection was approved by the Federal Executive Council (FEC) as of December 2022. The new draft whistleblower protection bill was presented to the National Assembly for consideration by President Muhammadu Buhari in May 2023. Buhari's term as President ends as of May 29, 2023.

Advocacy for whistleblower rights and protections

Many NGOs advocate for stronger and more comprehensive legal rights and protections for whistleblowers. Among them are the Government Accountability Project (GAP), Blueprint for Free Speech, Public Concern at Work (PCaW), the Open Democracy Advice Centre or in France, the Maison des Lanceurs d'Alerte (MLA). An international network - the Whistleblowing International Network (WIN) - aimed at gathering these NGOs.

Frank Serpico, an NYPD whistleblower, prefers to use the term "lamp-lighter" to describe the whistleblower's role as a watchman. The Lamplighter Project, which aims to encourage law enforcement officers to report corruption and abuse of power and helps them do so, is named based on Serpico's usage of the term.

Modern methods used for whistleblower protection

Whistleblowers who may be at risk from those they are exposing are now using encryption methods and anonymous content sharing software to protect their identity. Tor, a highly accessible anonymity network, is one that is frequently used by whistleblowers around the world. Tor has undergone a number of large security updates to protect the identities of potential whistleblowers who may wish to anonymously leak information.

Recently specialized whistleblowing software like SecureDrop and GlobaLeaks has been built on top of the Tor technology to incentivize and simplify its adoption for secure whistleblowing.

Whistleblowing hotline

In business, whistleblowing hotlines are usually deployed as a way of mitigating risk, with the intention of providing secure, anonymous reporting for employees or third party suppliers who may otherwise be fearful of reprisals from their employer. As such, implementing a corporate whistleblowing hotline is often seen as a step towards compliance, and can also highlight an organization's stance on ethics. It is widely agreed that implementing a dedicated service for whistleblowers has a positive effect on an organizational culture.

A whistleblowing hotline is sometimes also referred to as an ethics hotline or 'Speak Up' hotline and is often facilitated by an outsourced service provider to encourage potential disclosers to come forward.

In 2018, the Harvard Business Review published findings to support the idea that whistleblowing hotlines are crucial to keeping companies healthy, stating "More whistles blown are a sign of health, not illness."

In popular culture

One of the subplots for season 6 of the popular American TV show The Office focused on Andy Bernard, a salesman, discovering the printers of his company catch on fire, struggling with how to deal with the news, and the company's response to the whistleblower going public.

The 1998 film Star Trek: Insurrection involved Picard and the NCC-1701-E Enterprise crew risking their Starfleet careers to blow the whistle on a Federation conspiracy with the Son'a to forcibly relocate the Ba'ku from their planet.

In 2014, the rock/industrial band Laibach on its eighth studio album Spectre released a song titled "The Whistleblowers". It was released on 3 March 2014 under Mute Records.

In 2016, the rock band Thrice released a song titled "Whistleblower" off of the album To Be Everywhere Is to Be Nowhere. The song is written from the perspective of Snowden.

In July 2018, CBS debuted a new reality television show entitled Whistleblower, hosted by lawyer, former judge and police officer Alex Ferrer which covers qui tam suits under the False Claims Act against companies that have allegedly defrauded the federal government.

United States rainfall climatology

Average precipitation

The characteristics of United States rainfall climatology differ significantly across the United States and those under United States sovereignty. Summer and early fall bring brief, but frequent thundershowers and tropical cyclones which create a wet summer and drier winter in the eastern Gulf and lower East Coast. During the winter, and spring, Pacific storm systems bring Hawaii and the western United States most of their precipitation. Low pressure systems moving up the East Coast and through the Great Lakes, bring cold season precipitation to from the Midwest to New England, as well as Great Salt Lake. The snow to liquid ratio across the contiguous United States averages 13:1, meaning 13 inches (330 mm) of snow melts down to 1 inch (25 mm) of water.

During the summer, the North American monsoon combined with Gulf of California and Gulf of Mexico moisture moving around the subtropical ridge in the Atlantic Ocean bring the promise of afternoon and evening air-mass thunderstorms to the southern tier of the country as well as the Great Plains. Equatorward of the subtropical ridge, tropical cyclones enhance precipitation across southern and eastern sections of the country, as well as Puerto Rico, the United States Virgin Islands, the Northern Mariana Islands, Guam, and American Samoa. Over the top of the ridge, the jet stream brings a summer precipitation maximum to the Great Plains and western Great Lakes. Large thunderstorm areas known as mesoscale convective complexes move through the Plains, Midwest, and Great Lakes during the warm season, contributing up to 10% of the annual precipitation to the region.

The El Niño–Southern Oscillation affects the precipitation distribution, by altering rainfall patterns across the West, Midwest, the Southeast, and throughout the tropics. There is also evidence that global warming is leading to increased precipitation to the eastern portions of North America, while droughts are becoming more frequent in the western portions. Furthermore, global La Niña meteorological events are generally associated with drier and hotter conditions and further exacerbation of droughts in California and the Southwestern and to some extent the Southeastern United States. Meteorological scientists have observed that La Niñas have become more frequent over time.

General

A typical dry lakebed is seen in California, which is experiencing its worst megadrought in 1,200 years, precipitated by climate change, and is therefore water rationing.

The eastern part of the contiguous United States east of the 98th meridian, the mountains of the Pacific Northwest, the Willamette Valley, and the Sierra Nevada range are the wetter portions of the nation, with average rainfall exceeding 30 inches (760 mm) per year. The drier areas are the Desert Southwest, Great Basin, valleys of northeast Arizona, eastern Utah, and central Wyoming. Increased warming within urban heat islands leads to an increase in rainfall downwind of cities.

Alaska

Juneau averages over 50 inches (1,270 mm) of precipitation a year, while other areas in southeast Alaska receive over 275 inches (6,980 mm). South central Alaska does not get nearly as much rain as the southeast of Alaska, though it does get more snow. On average, Anchorage receives 16 inches (406 mm) of precipitation a year, with around 75 inches (1,905 mm) of snow. The northern coast of the Gulf of Alaska receives up to 150 inches (3,800 mm) of precipitation annually. Across western sections of the state, the northern side of the Seward Peninsula is a desert with less than 10 inches (250 mm) of precipitation annually, while some locations between Dillingham and Bethel average around 100 inches (2,540 mm) of precipitation. Inland, often less than 10 inches (250 mm) falls a year, but what precipitation falls during the winter tends to stay throughout the season. La Niña events lead to drier than normal conditions, while El Niño events do not have a correlation towards dry or wet conditions. Precipitation increases by 10 to 40 percent when the Pacific decadal oscillation is positive.

West

Impact of El Niño and La Niña on North America

From September through May, extratropical cyclones from the Pacific Ocean move inland into the region due to a southward migration of the jet stream during the cold season. This shift in the jet stream brings much of the annual precipitation to the region, and also brings the potential for heavy rain events. The West Coast occasionally experiences ocean-effect showers, usually in the form of rain at lower elevations south of the mouth of the Columbia River. These occur whenever an Arctic air mass from western Canada is drawn westward out over the Pacific Ocean, typically by way of the Fraser Valley, returning shoreward around a center of low pressure. Strong onshore flow is brought into the mountain ranges of the west, focusing significant precipitation into the Rocky Mountains, with rain shadows occurring in the Harney Basin, Great Basin, the central valley of California, and the lower Colorado River valley. In general, rainfall amounts are lower on the southern portions of the West coast. The biggest recipients of the precipitation are the coastal ranges such as the Olympic Mountains, the Cascades, and the Sierra Nevada range. Lesser amounts fall upon the Continental Divide. Cold-season precipitation into this region is the main supply of water to area rivers, such as the Colorado River and Rio Grande, and also acts as the main source of water to people living in this portion of the United States. During El Niño events, increased precipitation is expected in California due to a more southerly, zonal, storm track. California also enters a wet pattern when thunderstorm activity within the tropics associated with the Madden–Julian oscillation nears 150E longitude. During La Niña, increased precipitation is diverted into the Pacific Northwest due to a more northerly storm track.

Lake-effect snow off Great Salt Lake

The southern and southeastern sides of the Great Salt Lake receive significant lake-effect snow. Since the Great Salt Lake never freezes, the lake-effect can affect the weather along the Wasatch Front year round. The lake-effect largely contributes to the 55 inches (140 cm) to 80 inches (200 cm) annual snowfall amounts recorded south and east of the lake, with average snowfall amounts exceeding 600 inches (1,500 cm) in the Wasatch Mountains. The snow, which is often very light and dry due to the desert climate, is referred to as "The Greatest Snow on Earth" in the mountains. Lake-effect snow contributes to approximately 6-8 snowfalls per year in Salt Lake City, with approximately 10% of the city's precipitation being contributed by the phenomenon.

North American Monsoon

Arizona monsoon season clouds

The North American Monsoon (NAM) occurs from late June or early July into September, originating over Mexico and spreading into the southwest United States by mid-July. This allows the wet season to start in the Southwest during the summer rather than early fall as seen across the remainder of the West. Within the United States, it affects Arizona, New Mexico, Nevada, Utah, Colorado, West Texas, and California. The North American monsoon is known to many as the Summer, Southwest, Mexican or Arizona monsoon. It is also sometimes called the Desert Monsoon as a large part of the affected area is desert.

When precipitable water values near 1.32 inches (34 mm), brief but often torrential thunderstorms and the hurricane force winds and hail can occur, especially over mountainous terrain. This activity is occasionally enhanced by the passage of retrograding (westward-moving) upper cyclones moving under the subtropical ridge and the entrainment of the remnants of tropical storms. Tropical cyclones from the eastern Pacific contribute to the moisture within the monsoon system, and bring up to 20 percent of the average annual rainfall to southern California. Flash flooding is a serious danger during the monsoon season. Dry washes can become raging rivers in an instant, even when no storms are visible as a storm can cause a flash flood tens of miles away. Lightning strikes are also a significant danger. Because it is dangerous to be caught in the open when these storms suddenly appear, many golf courses in Arizona have thunderstorm warning systems.

As much as 45% of the annual rainfall across New Mexico occurs during the summer monsoon. Many desert plants are adapted to take advantage of this brief wet season. Because of the monsoons, the Sonoran and Mojave are considered relatively "wet" when ranked among other deserts such as the Sahara. Monsoons play a vital role in managing wildfire threat by providing moisture at higher elevations and feeding desert streams. Heavy monsoon rain can lead to excess winter plant growth, in turn a summer wildfire risk. A lack of monsoon rain can hamper summer seeding, reducing excess winter plant growth but worsening drought.

Thunderstorms during the North American Monsoon as seen from El Cajon, California. The thunderstorms rarely push beyond the Peninsular Ranges to the clear skies of the coastal strip.

Great Plains

Downslope winds off the Rocky Mountains can aid in forming the dry line. Major drought episodes in the midwestern United States are associated with an amplification of the upper tropospheric subtropical (or monsoon) ridge across the West and Plains, along with a weakening of the western edge of the "Bermuda high". During the summer, a southerly low-level jet draws moisture from the Gulf of Mexico. Additional moisture comes from more local sources, especially transpiring vegetation. Maximum precipitation generally occurs in late spring and early summer, with minimum precipitation in winter. During La Niña events, the storm track shifts far enough northward to bring wetter than normal conditions (in the form of increased snowfall) to the Midwestern states, as well as hot and dry summers.

The convective season for the Plains ranges between May and September. Organized systems of thunderstorms known as mesoscale convective systems develop over the region during this period, with a bulk of the activity occurring between midnight and 6 a.m. local time. The time of maximum precipitation during the day gradually varies from late afternoon near the slopes of the Rockies to early morning near the Ohio River valley, in part reflecting the west-to-east propagation of mesoscale convective systems. Mesoscale convective systems bring 30 to 70 percent of the annual warm season rainfall to the Plains. An especially long-lived and well-organized type of mesoscale convective system called a mesoscale convective complex produces on average 8% to 18% of the annual warm season rainfall across the Plains and Midwest. Squall lines account for 30% of the large thunderstorm complexes which move through the region.

Gulf Coast and lower Atlantic Coast south of New England

In general, northern and western portions of this region have a winter/spring maximum in precipitation with late summer/early fall being drier, while southern and eastern portions have a summer maximum and winter/early spring minimum in precipitation.

Most locations on the East Coast from Boston northward show a slight winter maximum as winter storms drop heavy precipitation. South of Boston, convective storms are common in the hot summer months and seasonal rainfall shows a slight summer maximum (though not at all stations). As one moves from Virginia Beach southward, summer becomes the wettest season, as convective thunderstorms created in the hot and moist tropical air mass drop brief but intense precipitation. In winter these areas still sees precipitation as low pressure systems moving across the southern United States often tap moisture from the Gulf of Mexico and drop cold season precipitation from eastern Texas to the New York area.

On the Florida peninsula, a strong monsoon becomes dominant, with dry winters and heavy summer rainfall. In winter the strong subtropical ridge creates the stable air over Florida with little convection and few fronts. Along the Gulf Coast, and the south Atlantic states, decaying tropical systems added to summers peak rainfall.

Cold season

The subtropical jet stream brings in upper level moisture from the Pacific Ocean during the cold season. Ahead of storm systems, significant moisture becomes drawn in from the Gulf of Mexico, which increases moisture within the atmospheric column and leads to precipitation ahead of extratropical cyclones. During the El Niño portion of ENSO, increased precipitation falls along the Gulf coast and Southeast due to a stronger than normal, and more southerly, polar jet stream. In the area around Memphis, Tennessee and across the state of Mississippi, there are two rainfall maxima in the winter and spring. Across Georgia and South Carolina, the first of the annual precipitation maxima occurs in late winter, during February or March. Alabama has an annual rainfall maximum in winter or spring and a dry summer.

Warm season

U.S. tropical cyclone rainfall maxima per state

During the summer, the subtropical ridge in the Atlantic Ocean strengthens, bringing in increasingly humid air from the warm Atlantic, Caribbean, and Gulf of Mexico. Once precipitable water values exceed 1.25 inches (32 mm), afternoon and evening thunderstorms break out at the western periphery of the subtropical ridge across the Southeast on a daily basis. Summer is the time of the second rainfall maximum during the year across Georgia, and the time of the main rainfall maximum in Florida. During the late summer and fall, tropical cyclones move into the region from the Atlantic and Gulf of Mexico, supplying portions of the area with one-quarter of their annual rainfall, on average. Fall is the time of the rainfall minimum across Louisiana. Sometimes, Gulf moisture sneaks up the Front Range of Rockies as far north as the northern High Plains, bringing higher dewpoint air into states such as Wyoming and Montana.

Great Lakes

Overall, late spring and early summer is the wettest time of year for the western portion of the region, with a winter minimum in precipitation. This is due to warm, moist, and unstable air moving along the jet stream where it is centralized. Which brings precipitation along the westerlies. In contrast, eastern portions of the regions have two precipitation maximums, one during spring, and again in November. While July and August are the driest months in the region. The reason being that this region is further away from the unstable air of the central U.S and has more moderators to the climate. Due to the fact that storms and winds generally move west to east, the winds that blow from the Great Lakes during the summer keep the area more stable. With thunderstorms generally being less common.

Cold season

A linear single band lake effect snowsquall

Extratropical cyclones can bring moderate to heavy snowfall during the cold season. On the backside of these systems, particularly those moving through the eastern United States, lake effect snowfall is possible. Low level cold in the winter sweeping in from Canada combine with relatively warmer, unfrozen lakes to produce dramatic lake-effect snow on the eastern and southern shores of the Great Lakes. Lake-effect precipitation produces a significant difference between the snowfall around the Great Lakes, sometimes within small distances. Lake effect snowfall accounts for 30 to 60 percent of the annual snowfall near the coasts of the Great Lakes. Lake Erie has the distinction of being the only great lake capable of completely freezing over during the winter due to its relative shallowness. Once frozen, the resulting ice cover alleviates lake-effect snow downwind of the lake. The influence of the Great Lakes allows the region to lie within a Humid Continental Climate regime. Although certain scientists have argued that the eastern third resemble more of an oceanic climate

Warm season

Satellite view of a supercell near the Great Lakes

Weather systems in the westerlies that cause precipitation move along jet stream, which migrates north into the region by summer. This also increases the likelihood for severe weather to develop due to stronger upper-level divergence in its vicinity. Mesoscale convective complexes move into the region from the Plains from late April through mid-July, with June the peak month for the western portions of the Great Lakes. These systems contribute about 2% of the annual precipitation for the region. Also, remnants of tropical cyclones occasionally move northward into the region, though their overall contribution to precipitation across the region is minimal. From the spring through the summer, areas near the shores of the relatively cooler Great Lakes develop sea breezes, which lowers rainfall amounts and increases sunshine near the immediate coastline. The eastern Great Lakes are significantly drier during the summer.

Northeast

Satellite image of the intense nor'easter responsible for the North American blizzard of 2006.

Average precipitation across the region show maxima along the coastal plain and along the mountains of the Appalachians. Between 28 inches (710 mm) and 62 inches (1,600 mm) of precipitation falls annually across the area. Seasonally, there are slight changes to precipitation distribution through the year. For example, Burlington, Vermont has a summer maximum and a winter minimum. In contrast, Portland, Maine has a fall and winter maximum, with a summer minimum in precipitation. Temporally, a maximum in precipitation is seen around three peak times: 3 a.m., 10 a.m., and 6 p.m. During the summer, the 6 p.m. peak is most pronounced.

Cold season

Coastal extratropical cyclones, known as nor'easters, bring a bulk of the wintry precipitation to the region during the cold season as they track parallel to the coastline, forming along the natural temperature gradient of the Gulf stream before moving up the coastline. The Appalachian Mountains largely shield New York City and Philadelphia from picking up any lake-effect snow, though ocean-effect snows are possible near Cape Cod. The Finger Lakes of New York are long enough for lake-effect precipitation. Lake-effect snow from the Finger Lakes occurs in upstate New York until those lakes freeze over. Bay-effect snows fall downwind of Delaware Bay, Chesapeake Bay, and Massachusetts Bay when the basic criteria are met. Ocean effect snows are possible downwind of the Gulf Stream across the Southeast.

Warm season

During the summer and early fall, mesoscale convective systems can move into the area from Canada and the Great Lakes. Tropical cyclones and their remains occasionally move into the region from the south and southwest. Recently, the region has experienced a couple heavy rainfall events that exceeded the 50-year return period, during October 1996 and October 1998, which suggest an increase in heavy rainfall along the coast.

Pacific islands

Hawaii

Systems such as this Kona low from November 4, 1995 bring Hawaii much of their annual rainfall

Snow, although not usually associated with tropics, falls at higher elevations on the Big Island, on Mauna Loa as well as Mauna Kea, which reaches an altitude of 13,796 feet (4,205 m), in some winter months. Snow only rarely falls on Maui's Haleakala. Mount Waiʻaleʻale (Waiʻaleʻale), on the island of Kauai, is notable for its extreme rainfall, as it has the second highest average annual rainfall on Earth, with 460 inches (12,000 mm). Storm systems affect the state with heavy rains between October and March. Showers are common across the island chain, but thunderstorms are relatively rare. Local climates vary considerably on each island due to their topography, divisible into windward (Koʻolau) and leeward (Kona) regions based upon location relative to the higher mountains. The Kona coast is the only area in Hawaii with a summer precipitation maximum. Windward sides face the east to northeast trade winds and receive much more rainfall; leeward sides are drier and sunnier, with less rain and less cloud cover. In the late winter and spring during El Niño events, drier than average conditions can be expected in Hawaii.

Northern Marianas

The islands have a tropical marine climate moderated by seasonal northeast trade winds. There is a dry season which stretches from December to June, and a rainy season from July to November. Saipan's average annual precipitation is 82.36 inches (2,092 mm), with 67 percent falling during the rainy season. Typhoons frequent the island chain, which can lead to excessive rainfall.

Guam

Typhoons, such as Pongsona (2002), can bring excessive rainfall to Guam

Guam's climate is moderated by east to northeast trade winds through the year. The average annual rainfall for the island is 86 inches (2,200 mm). There is a distinct dry season from January to June, and a rainy season from July to December. Typhoons frequent the island, which can lead to excessive rainfall. During El Niño years, dry season precipitation averages below normal. However, the threat of a tropical cyclone is over triple what is normal during El Niño years, so extreme shorter duration rainfall events are possible.

American Samoa

American Samoa's climate regime is dominated by southeast trade winds. The island dependency is wet, with annual rainfall averaging near 120 inches (3,000 mm) at the airport, with amounts closer to 200 inches (5,100 mm) in other areas. There is a distinct rainy season when tropical cyclones occasionally visit between November and April. The dry season lasts from May to October. During El Niño events, precipitation averages about 10 percent above normal, while La Niña events lead to precipitation amounts which average close to 10 percent below normal.

Pago Pago harbor in American Samoa has the highest annual rainfall of any harbor in the world. This is due to the nearby Rainmaker Mountain.

Atlantic islands

Puerto Rico

There is a pronounced rainy season from April to November across the commonwealth, encompassing the annual hurricane season. Due to the Commonwealth's topography, rainfall varies greatly across the archipelago. Pico del Este averages 171.09 inches (4,346 mm) of rainfall yearly while Magueyes Island averages only 29.32 inches (745 mm) a year. Despite known changes in tropical cyclone activity due to changes in the El Niño/Southern Oscillation (ENSO), there is no known relationship between rainfall in Puerto Rico and the ENSO cycle. However, when values of the North Atlantic oscillation are high during the winter, precipitation is lower than average for Puerto Rico. There have not been any documented cases of snow falling within Puerto Rico, though occasionally it is brought in from elsewhere as a publicity stunt.

United States Virgin Islands

The climate of the United States Virgin Islands has sustained easterly trade winds through the year. There is a rainy season which lasts from September to November, when hurricanes are more prone to visit the island chain. The average rainfall through the island chain ranges from 51.55 inches (1,309 mm) at Annually to 37.79 inches (960 mm) at East Hill.

Changes due to global warming

US precipitation trends (lower 48), 1895–2014. Raw data:

Increasing temperatures tend to increase evaporation which leads to more precipitation. As average global temperatures have risen, average global precipitation has also increased. Precipitation has generally increased over land north of 30°N from 1900 to 2005, but declined over the tropics since the 1970s. Eastern portions of North America have become wetter. There has been an increase in the number of heavy precipitation events over many areas during the past century, as well as an increase since the 1970s in the prevalence of droughts—especially in the tropics and subtropics. Over the contiguous United States, total annual precipitation increased at an average rate of 6.1 percent per century since 1900, with the greatest increases within the East North Central climate region (11.6 percent per century) and the South (11.1 percent). Hawaii was the only region to show a decrease (−9.25 percent). From this excess precipitation, crop losses are expected to increase by US$3 billion (2002 dollars) annually over the next 30 years.

Monday, December 25, 2023

El Niño–Southern Oscillation

Southern Oscillation Index timeseries from 1876 to 2023. The Southern Oscillation is the atmospheric component of El Niño. This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters.

El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. The Southern Oscillation is the accompanying atmospheric component, coupled with the sea temperature change: El Niño is accompanied by high air surface pressure in the tropical western Pacific and La Niña with low air surface pressure there. The two periods last several months each and typically occur every few years with varying intensity per period.

The two phases relate to the Walker circulation, which was discovered by Gilbert Walker during the early twentieth century. The Walker circulation is caused by the pressure gradient force that results from a high-pressure area over the eastern Pacific Ocean, and a low-pressure system over Indonesia. Weakening or reversal of the Walker circulation (which includes the trade winds) decreases or eliminates the upwelling of cold deep sea water, thus creating El Niño by causing the ocean surface to reach above average temperatures. An especially strong Walker circulation causes La Niña, resulting in cooler ocean temperatures due to increased upwelling.

Mechanisms that cause the oscillation remain under study. The extremes of this climate pattern's oscillations cause extreme weather (such as floods and droughts) in many regions of the world. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected.

In climate change science, ENSO is known as one of the internal climate variability phenomena. The other two main ones are Pacific Decadal Variability (or oscillation) and Atlantic Multi-decadal Variability (or oscillation).

Terminology

An early recorded mention of the term "El Niño" ("The Boy" in Spanish) to refer to climate occurred in 1892, when Captain Camilo Carrillo told the geographical society congress in Lima that Peruvian sailors named the warm south-flowing current "El Niño" because it was most noticeable around Christmas. Although pre-Columbian societies were certainly aware of the phenomenon, the indigenous names for it have been lost to history.

Originally, the term El Niño applied to an annual weak warm ocean current that ran southwards along the coast of Peru and Ecuador at about Christmas time. However, over time the term has evolved and now refers to the warm and negative phase of the El Niño–Southern Oscillation (ENSO). La Niña ("The Girl" in Spanish) is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern.

Outline

The El Niño–Southern Oscillation is a single climate phenomenon that periodically fluctuates between three phases: Neutral, La Niña or El Niño. La Niña and El Niño are opposite phases which require certain changes to take place in both the ocean and the atmosphere before an event is declared.

Normally the northward flowing Humboldt Current brings relatively cold water from the Southern Ocean northwards along South America's west coast to the tropics, where it is enhanced by up-welling taking place along the coast of Peru. Along the equator, trade winds cause the ocean currents in the eastern Pacific to draw water from the deeper ocean to the surface, thus cooling the ocean surface. Under the influence of the equatorial trade winds, this cold water flows westwards along the equator where it is slowly heated by the sun. As a direct result sea surface temperatures in the western Pacific are generally warmer, by about 8–10 °C (14–18 °F) than those in the Eastern Pacific. This warmer area of ocean is a source for convection and is associated with cloudiness and rainfall. During El Niño years the cold water weakens or disappears completely as the water in the Central and Eastern Pacific becomes as warm as the Western Pacific.

Walker circulation

Diagram of the quasi-equilibrium and La Niña phase of the Southern Oscillation. The Walker circulation is seen at the surface as easterly trade winds which move water and air warmed by the sun towards the west. The western side of the equatorial Pacific is characterized by warm, wet low pressure weather as the collected moisture is dumped in the form of typhoons and thunderstorms. The ocean is some 60 centimetres (24 in) higher in the western Pacific as the result of this motion. The water and air are returned to the east. Both are now much cooler, and the air is much drier. An El Niño episode is characterised by a breakdown of this water and air cycle, resulting in relatively warm water and moist air in the eastern Pacific.

The Walker circulation is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean, and a low pressure system over Indonesia. The Walker circulations of the tropical Indian, Pacific, and Atlantic basins result in westerly surface winds in northern summer in the first basin and easterly winds in the second and third basins. As a result, the temperature structure of the three oceans display dramatic asymmetries. The equatorial Pacific and Atlantic both have cool surface temperatures in northern summer in the east, while cooler surface temperatures prevail only in the western Indian Ocean. These changes in surface temperature reflect changes in the depth of the thermocline.

Changes in the Walker circulation with time occur in conjunction with changes in surface temperature. Some of these changes are forced externally, such as the seasonal shift of the sun into the Northern Hemisphere in summer. Other changes appear to be the result of coupled ocean-atmosphere feedback in which, for example, easterly winds cause the sea surface temperature to fall in the east, enhancing the zonal heat contrast and hence intensifying easterly winds across the basin. These anomalous easterlies induce more equatorial upwelling and raise the thermocline in the east, amplifying the initial cooling by the southerlies. This coupled ocean-atmosphere feedback was originally proposed by Bjerknes. From an oceanographic point of view, the equatorial cold tongue is caused by easterly winds. Were the Earth climate symmetric about the equator, cross-equatorial wind would vanish, and the cold tongue would be much weaker and have a very different zonal structure than is observed today.

During non-El Niño conditions, the Walker circulation is seen at the surface as easterly trade winds that move water and air warmed by the sun toward the west. This also creates ocean upwelling off the coasts of Peru and Ecuador and brings nutrient-rich cold water to the surface, increasing fishing stocks. The western side of the equatorial Pacific is characterized by warm, wet, low-pressure weather as the collected moisture is dumped in the form of typhoons and thunderstorms. The ocean is some 60 cm (24 in) higher in the western Pacific as the result of this motion.

Sea surface temperature oscillation

The various "Niño regions" where sea surface temperatures are monitored to determine the current ENSO phase (warm or cold)

Within the National Oceanic and Atmospheric Administration in the United States, sea surface temperatures in the Niño 3.4 region, which stretches from the 120th to 170th meridians west longitude astride the equator five degrees of latitude on either side, are monitored. This region is approximately 3,000 kilometres (1,900 mi) to the southeast of Hawaii. The most recent three-month average for the area is computed, and if the region is more than 0.5 °C (0.9 °F) above (or below) normal for that period, then an El Niño (or La Niña) is considered in progress. The United Kingdom's Met Office also uses a several month period to determine ENSO state. When this warming or cooling occurs for only seven to nine months, it is classified as El Niño/La Niña "conditions"; when it occurs for more than that period, it is classified as El Niño/La Niña "episodes".

Normal Pacific pattern: Equatorial winds gather warm water pool toward the west. Cold water upwells along South American coast. (NOAA / PMEL / TAO)
 
El Niño conditions: Warm water pool approaches the South American coast. The absence of cold upwelling increases warming.
 
La Niña conditions: Warm water is farther west than usual.

Neutral phase

Average equatorial Pacific temperatures

If the temperature variation from climatology is within 0.5 °C (0.9 °F), ENSO conditions are described as neutral. Neutral conditions are the transition between warm and cold phases of ENSO. Ocean temperatures (by definition), tropical precipitation, and wind patterns are near average conditions during this phase. Close to half of all years are within neutral periods. During the neutral ENSO phase, other climate anomalies/patterns such as the sign of the North Atlantic Oscillation or the Pacific–North American teleconnection pattern exert more influence.

The 1997 El Niño observed by TOPEX/Poseidon

Warm phase

When the Walker circulation weakens or reverses and the Hadley circulation strengthens an El Niño results, causing the ocean surface to be warmer than average, as upwelling of cold water occurs less or not at all offshore northwestern South America. El Niño (/ɛlˈnnj/, /-ˈnɪn-/, Spanish pronunciation: [el ˈniɲo]) is associated with a band of warmer than average ocean water temperatures that periodically develops off the Pacific coast of South America. El niño is Spanish for "the child boy", and the capitalized term El Niño refers to the Christ child, Jesus, because periodic warming in the Pacific near South America is usually noticed around Christmas. El Niño accompanies high air surface pressure in the western Pacific. Mechanisms that cause the oscillation remain under study.

Cold phase

An especially strong Walker circulation causes La Niña, resulting in cooler ocean temperatures in the central and eastern tropical Pacific Ocean due to increased upwelling. La Niña (/lɑːˈnnjə/, Spanish pronunciation: [la ˈniɲa]) is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño Southern Oscillation climate pattern. The name La Niña originates from Spanish, meaning "the child girl", analogous to El Niño meaning "the child boy". During a period of La Niña the sea surface temperature across the equatorial eastern central Pacific will be lower than normal by 3–5 °C. In the United States, an appearance of La Niña happens for at least five months of La Niña conditions. However, each country and island nation has a different threshold for what constitutes a La Niña event, which is tailored to their specific interests. The Japan Meteorological Agency for example, declares that a La Niña event has started when the average five month sea surface temperature deviation for the NINO.3 region, is over 0.5 °C (0.90 °F) cooler for 6 consecutive months or longer.

Transitional phases

Transitional phases at the onset or departure of El Niño or La Niña can also be important factors on global weather by affecting teleconnections. Significant episodes, known as Trans-Niño, are measured by the Trans-Niño index (TNI). Examples of affected short-time climate in North America include precipitation in the Northwest US and intense tornado activity in the contiguous US.

Southern Oscillation

The regions where the air pressure are measured and compared to generate the Southern Oscillation Index
Southern Oscillation Index correlated with mean sea level pressure.

The Southern Oscillation is the atmospheric component of El Niño. This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters. The strength of the Southern Oscillation is measured by the Southern Oscillation Index (SOI). The SOI is computed from fluctuations in the surface air pressure difference between Tahiti (in the Pacific) and Darwin, Australia (on the Indian Ocean).

  • El Niño episodes have negative SOI, meaning there is lower pressure over Tahiti and higher pressure in Darwin.
  • La Niña episodes have positive SOI, meaning there is higher pressure in Tahiti and lower in Darwin.

Low atmospheric pressure tends to occur over warm water and high pressure occurs over cold water, in part because of deep convection over the warm water. El Niño episodes are defined as sustained warming of the central and eastern tropical Pacific Ocean, thus resulting in a decrease in the strength of the Pacific trade winds, and a reduction in rainfall over eastern and northern Australia. La Niña episodes are defined as sustained cooling of the central and eastern tropical Pacific Ocean, thus resulting in an increase in the strength of the Pacific trade winds, and the opposite effects in Australia when compared to El Niño.

Although the Southern Oscillation Index has a long station record going back to the 1800s, its reliability is limited due to the presence of both Darwin and Tahiti well south of the Equator, resulting in the surface air pressure at both locations being less directly related to ENSO. To overcome this question, a new index was created, being named the Equatorial Southern Oscillation Index (EQSOI). To generate this index data, two new regions, centered on the Equator, were delimited to create a new index: The western one is located over Indonesia and the eastern one is located over equatorial Pacific, close to the South American coast. However, data on EQSOI goes back only to 1949.

Related patterns

Madden–Julian oscillation

A Hovmöller diagram of the 5-day running mean of outgoing longwave radiation showing the MJO. Time increases from top to bottom in the figure, so contours that are oriented from upper-left to lower-right represent movement from west to east.
The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric Research (NCAR). It is a large-scale coupling between atmospheric circulation and tropical deep atmospheric convection. Unlike a standing pattern like the El Niño–Southern Oscillation (ENSO), the Madden–Julian oscillation is a traveling pattern that propagates eastward, at approximately 4 to 8 m/s (14 to 29 km/h; 9 to 18 mph), through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself most clearly as anomalous rainfall.

Interactions with global warming

Colored bars show how El Niño years (red, regional warming) and La Niña years (blue, regional cooling) relate to overall global warming. The El Niño–Southern Oscillation has been linked to variability in longer-term global average temperature increase.

In climate change science, ENSO is known as one of the internal climate variability phenomena. The other two main ones are Pacific Decadal Variability (or oscillation) and Atlantic Multi-decadal Variability (or oscillation).

El Niño events cause short-term (approximately 1 year in length) spikes in global average surface temperature while La Niña events cause short term cooling. Therefore, the relative frequency of El Niño compared to La Niña events can affect global temperature trends on decadal timescales. Over the last several decades, the number of El Niño events increased, and the number of La Niña events decreased, although observation of ENSO for much longer is needed to detect robust changes.

The studies of historical data show the recent El Niño variation is most likely linked to global warming. For example, one of the most recent results, even after subtracting the positive influence of decadal variation, is shown to be possibly present in the ENSO trend, the amplitude of the ENSO variability in the observed data still increases, by as much as 60% in the last 50 years. A study published in 2023 by CSIRO researchers found that climate change may have increased by two times the likelihood of strong El Niño events and nine times the likelihood of strong La Niña events. The study claims it found a consensus between different models and experiments.

Future trends in ENSO are uncertain as different models make different predictions. It may be that the observed phenomenon of more frequent and stronger El Niño events occurs only in the initial phase of the global warming, and then (e.g., after the lower layers of the ocean get warmer, as well), El Niño will become weaker. It may also be that the stabilizing and destabilizing forces influencing the phenomenon will eventually compensate for each other. More research is needed to provide a better answer to that question. The ENSO is considered to be a potential tipping element in Earth's climate and, under the global warming, can enhance or alternate regional climate extreme events through a strengthened teleconnection. For example, an increase in the frequency and magnitude of El Niño events have triggered warmer than usual temperatures over the Indian Ocean, by modulating the Walker circulation. This has resulted in a rapid warming of the Indian Ocean, and consequently a weakening of the Asian Monsoon.

The IPCC Sixth Assessment Report summarized the state of the art of research in 2021 into the future of ENSO as follows:

  • "In the long term, it is very likely that the precipitation variance related to El Niño–Southern Oscillation will increase" and
  • "It is very likely that rainfall variability related to changes in the strength and spatial extent of ENSO teleconnections will lead to significant changes at regional scale". and
  • "There is medium confidence that both ENSO amplitude and the frequency of high-magnitude events since 1950 are higher than over the period from 1850 and possibly as far back as 1400".

Impacts

On precipitation

Regional impacts of El Niño
 
Regional impacts of La Niña.

Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected by ENSO. The effects of El Niño in South America are direct and strong. An El Niño is associated with warm and very wet weather months in April–October along the coasts of northern Peru and Ecuador, causing major flooding whenever the event is strong or extreme. La Niña causes a drop in sea surface temperatures over Southeast Asia and heavy rains over Malaysia, the Philippines, and Indonesia.

To the north across Alaska, La Niña events lead to drier than normal conditions, while El Niño events do not have a correlation towards dry or wet conditions. During El Niño events, increased precipitation is expected in California due to a more southerly, zonal, storm track. During La Niña, increased precipitation is diverted into the Pacific Northwest due to a more northerly storm track. During La Niña events, the storm track shifts far enough northward to bring wetter than normal winter conditions (in the form of increased snowfall) to the Midwestern states, as well as hot and dry summers. During the El Niño portion of ENSO, increased precipitation falls along the Gulf coast and Southeast due to a stronger than normal, and more southerly, polar jet stream.

In the late winter and spring during El Niño events, drier than average conditions can be expected in Hawaii. On Guam during El Niño years, dry season precipitation averages below normal. However, the threat of a tropical cyclone is over triple what is normal during El Niño years, so extreme shorter duration rainfall events are possible. On American Samoa during El Niño events, precipitation averages about 10 percent above normal, while La Niña events lead to precipitation amounts which average close to 10 percent below normal. ENSO is linked to rainfall over Puerto Rico. During an El Niño, snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well-below normal across the Upper Midwest and Great Lakes states. During a La Niña, snowfall is above normal across the Pacific Northwest and western Great Lakes. In Western Asia, during the region's November–April rainy season, it was discovered that in the El Niño phase there was increased precipitation, and in the La Niña phase there was a reduced amount of precipitation on average.

Although ENSO can dramatically affect precipitation, even severe droughts and rainstorms in ENSO areas are not always deadly. Scholar Mike Davis cites ENSO as responsible for droughts in India and China in the late nineteenth century, but argues that nations in these areas avoided devastating famine during these droughts with institutional preparation and organized relief efforts.

On Tehuantepecers

The synoptic condition for the Tehuantepecer, a violent mountain-gap wind in between the mountains of Mexico and Guatemala, is associated with high-pressure system forming in Sierra Madre of Mexico in the wake of an advancing cold front, which causes winds to accelerate through the Isthmus of Tehuantepec. Tehuantepecers primarily occur during the cold season months for the region in the wake of cold fronts, between October and February, with a summer maximum in July caused by the westward extension of the Azores-Bermuda high pressure system. Wind magnitude is greater during El Niño years than during La Niña years, due to the more frequent cold frontal incursions during El Niño winters. Tehuantepec winds reach 20 knots (40 km/h) to 45 knots (80 km/h), and on rare occasions 100 knots (190 km/h). The wind's direction is from the north to north-northeast. It leads to a localized acceleration of the trade winds in the region, and can enhance thunderstorm activity when it interacts with the Intertropical Convergence Zone. The effects can last from a few hours to six days.

On coral bleaching

Following the El Nino event in 1997 – 1998, the Pacific Marine Environmental Laboratory attributes the first large-scale coral bleaching event to the warming waters.

On hurricanes

Based on modeled and observed accumulated cyclone energy (ACE), El Niño years usually result in less active hurricane seasons in the Atlantic Ocean, but instead favor a shift of tropical cyclone activity in the Pacific Ocean, compared to La Niña years favoring above average hurricane development in the Atlantic and less so in the Pacific basin.

Variations

The traditional ENSO (El Niño Southern Oscillation), also called Eastern Pacific (EP) ENSO, involves temperature anomalies in the eastern Pacific. However, in the 1990s and 2000s, nontraditional ENSO conditions were observed, in which the usual place of the temperature anomaly (Niño 1 and 2) is not affected, but an anomaly arises in the central Pacific (Niño 3.4). The phenomenon is called Central Pacific (CP) ENSO, "dateline" ENSO (because the anomaly arises near the dateline), or ENSO "Modoki" (Modoki is Japanese for "similar, but different"). There are flavors of ENSO additional to EP and CP types and some scientists argue that ENSO exists as a continuum often with hybrid types.

The effects of the CP ENSO are different from those of the traditional EP ENSO. The El Niño Modoki leads to more hurricanes more frequently making landfall in the Atlantic. La Niña Modoki leads to a rainfall increase over northwestern Australia and northern Murray–Darling basin, rather than over the east as in a conventional La Niña. Also, La Niña Modoki increases the frequency of cyclonic storms over Bay of Bengal, but decreases the occurrence of severe storms in the Indian Ocean.

The recent discovery of ENSO Modoki has some scientists believing it to be linked to global warming. However, comprehensive satellite data go back only to 1979. More research must be done to find the correlation and study past El Niño episodes. More generally, there is no scientific consensus on how/if climate change might affect ENSO.

There is also a scientific debate on the very existence of this "new" ENSO. Indeed, a number of studies dispute the reality of this statistical distinction or its increasing occurrence, or both, either arguing the reliable record is too short to detect such a distinction, finding no distinction or trend using other statistical approaches, or that other types should be distinguished, such as standard and extreme ENSO.

Following the asymmetric nature of the warm and cold phases of ENSO, some studies could not identify such distinctions for La Niña, both in observations and in the climate models, but some sources indicate that there is a variation on La Niña with cooler waters on central Pacific and average or warmer water temperatures on both eastern and western Pacific, also showing eastern Pacific Ocean currents going to the opposite direction compared to the currents in traditional La Niñas.

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