Re: Strikes occur almost daily . . .
"a few chunks (a fistful of scattered grams, possibly ounces, per bolide that would explode in the atmosphere due to heat exchange upon entry) that reach a solid surface, mainly around the poles."
Why the poles? I would expect a random distribution, or if anything, a bias towards equatorial regions that get more direct hits from the ecliptic (sp.?) plane.
All the rest of the explanation sounded great.