Atmospheric Cosmic Dust Fluxes in the Size Range 10–4 to 10 Centimeters

摘要: We show that the long-time-averaged "effective" flux of extraterrestrial particles (ETPs) on Earth over a wide range particle sizes is significantly different from incident Earth's atmosphere, as result ablation and fragmentation larger objects in atmosphere. have analytically deduced "modified" size spectrum ETPs using equilibrium model developed by Dohnanyi for meteoroid population interplanetary space direct observations large number meteorites Our shows most secondary are produced radii 1 cm to m, where differential relatively much flatter, compared either end. A significant fraction impacting mass, about 50%, volatilized during would be globally deposited, will smaller than few microns, contrast remaining mass greater 10-20 μm size, which we expect deposited close point impact object. Although fluxes greatly enhanced, these not sampled efficiently stratospheric collections, since they whose rates small. Thus, collections biased toward collection primary ETPs, whereas terrestrial accumulations representing (area × time) products, case ocean sediments, sample fragmented particles.