Chemistry at Venus' Cloud Tops

There is a curiosity I keep wondering about concerning the inner solar system’s planet’s atmospheres.  I have often read how Earth’s powerful magnetic field helps to deflect the solar wind and maintain our dense atmosphere.  Mercury, the moon, and Mars have only weak magnetic fields and it is asserted that their little to no atmospheres are the result of the wind ionizing the gasses and then literally stripping them away.

But there was always one obvious exception to this generality:  Venus.  Venus too has no magnetic field but easily possesses the densest atmosphere of the inner worlds, much denser than Earth’s.  Part of this is probably due to the carbon dioxide composition of Venus’ atmosphere; CO₂ is a large, heavy molecule that is no doubt easier to retain than Earth-like gasses of oxygen, nitrogen, argon, and water vapor.  Furthermore, the active (though periodic) heavy volcanism on Venus means that this gas is being regularly generated and introduced into the planet’s atmosphere (the early loss of heavy volcanism is probably why the same hasn’t occurred on Mars), perhaps as fast or even faster than the solar wind can strip it away.

But I wonder if there is another reason. Venus is topped by a thick layer of sulfuric acid clouds, which largely (I think) overlays the carbon dioxide nearer the surface.  This layer could act as a shield against incoming electrons and protons from the sun.  Sulfuric acid is a very heavy molecule which would probably fracture into smaller radicals and ions when struck by such particles.  Possible reactions could be:

 H₂SO₄ + e^- ® OH^- + HSO₃·

 H₂SO₄ + p⁺ ® H₂O₂ + SO₂²⁺

If OH^- ions are formed they are probably to weak to be helped by Venus’ gravity, but they might recombine with other radicals/ions first.  The other species will probably also hang around long enough to recreate sulfuric acid, while scattering the electrons and protons at lower energies.  Bear in mind, this is probably a very small sampling of the kind of chemistry that occurs at Venus’ cloud levels.  If it is happening then Venus protects its atmosphere with chemistry instead of magnetism.  Similar chemistry could be going on at Saturn’s moon Titan’s cloud tops, although the solar wind is much weaker there.

A Favorite Way of Picturing Deep Time

Portraying geology and geology in terms of "deep time" (essentially goin back to the beginning of Earth and the solar system) isn't easy, but I think this picture does a reasonably good job of it.

Spice, Salt, and Civilizations?

Some years ago a writer I much admire named Jared Diamond wrote Guns, Germs, and Steel, the main premise of which (though it isn't in the title, oddly) is that Eurasian civilizations took off sooner and faster than African or American due to the large number of domesticatable plants and animals living there (e.g., cattle, swine, chickens, wheat and other grains, etc.), which is why Eurasia came to dominate the rest of the world so badly once we developed ocean going vessels.

If we define civilization as the transition from nomadic to settled cultures, there may be another factor, this one concerning food.  The reason uncivilized cultures are nomadic is that food is a constant requirement but, with obvious exceptions like tropical areas, is not plentiful anywhere all year round.  Their is a time of plenty, and a time of -- well, what?  Without means to preserve (many) foods, it's either go hungry or move to new places of plenty.  Hense nomadism.

We take freezing and refrigeration (in technologically modern cultures) as the obvious way to preserve meat, fish, and other perishable food items, but that's only been quite recent (and still is no where near universal).  Prior to cold, the main preservatives used by humans were salt and spices -- even if you went to market everyday such places often had to be kept going by sellers and producers using salt & spices to keep their foods reasonably fresh for their buyers.

I don't know what the archeological evidence here is (which means I'll have to check it), but may I suggest that at least part of what triggered settled behaviors in Homo sapiens was the discovery of substances which can preserve perishable foods for fairly long periods?  At least this makes sense to me.  Nomadism is a brutal way of life, happily abandoned the moment people can do so.  On the go most of the time, carrying all you own with you, over mountain passes and deserts and other nasty places?  In truth, it doesn't even sound romantic.

When you first settle, you're still uncivilized in all other ways.  A stone-age culture that doesn't move about.  Although there are other obvious reasons, perhaps one of the causes of tropical people living "primitive" lives long after the rest of us have abandoned them, is the year-round presence of food.  They're settled because they don't have to move.  And even though many of them do use preservation methods, they're not an absolute essential; you literally can get fresh food every day.

Well.  I suppose I'm not the first person to think of this.  But I haven't seen a book entitled Spice, Salt, and Civilizations, anywhere, by anyone.  So proably not too much has been done with this idea amongst the lay public, and maybe not even among scientists.  If so, I'd love to hear about it.