Just adding a few links, basically, there's a bit of magnetosphere on Mars right now which provides some patchy shielding from the solar wind, but no shielding from galactic cosmic radiation. Most relevant for study of escape of gases from the atmosphere - below these patches of magnetosphere then the escape of gases is slower than elsewhere on Mars.
I don't know if the shielding would be enough to give some protection from solar flares for the surface below these spots - during a large solar flare (very rare event only every few decades) then Mars can receive several years of radiation equivalent, flare as perhaps several outbursts over a few days of the year. You'd think if it makes a difference to escape of gases from the atmosphere that it would also make a difference to measured radiation levels on the surface. But how much I don't know. And in any case if it did anything, would only make a significant difference for a few days every few decades.
In any case overall not much reduction.
This shows areas of Mars which have high patches of ionosphere
Here is a paper about the earlier stronger magnetic fields on Mars, and whether it made any difference to any Martian life forms on early Mars Page on www.dlr.de
Found that only cosmic radiation at lower energy levels are affected, so doesn't provide much shielding. A thicker atmosphere would make more difference.
I don't know if the shielding would be enough to give some protection from solar flares for the surface below these spots - during a large solar flare (very rare event only every few decades) then Mars can receive several years of radiation equivalent, flare as perhaps several outbursts over a few days of the year. You'd think if it makes a difference to escape of gases from the atmosphere that it would also make a difference to measured radiation levels on the surface. But how much I don't know. And in any case if it did anything, would only make a significant difference for a few days every few decades.
In any case overall not much reduction.
This shows areas of Mars which have high patches of ionosphere
Colors represent the probability that Mars Global Surveyor will be in the ionosphere when orbiting at 400 kilometer's altitude. Blue is a low probability, meaning the spacecraft is usually in the solar wind and the ionosphere is below the spacecraft. Yellow and red show where the ionosphere often protrudes above 400 kilometers altitude. (Credit: David Mitchell, UC Berkeley.)
The Solar Wind at Mars
Here is a paper about the earlier stronger magnetic fields on Mars, and whether it made any difference to any Martian life forms on early Mars Page on www.dlr.de
Found that only cosmic radiation at lower energy levels are affected, so doesn't provide much shielding. A thicker atmosphere would make more difference.
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Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
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