In:
Journal of Geophysical Research: Atmospheres, American Geophysical Union (AGU), Vol. 122, No. 20 ( 2017-10-27)
Abstract:
About 40 t of space dust enters the atmosphere every day. Around 20% of the dust vaporizes during entry because the particles enter at speeds of over 40,000 kph. The resulting metal vapors (principally Fe, Mg, and Si) then oxidize and condense into tiny particles known as meteoric smoke, around 1 nm in radius. This study examines where the meteoric smoke is deposited at the Earth's surface. The smoke has been detected in polar ice cores, with a much higher deposition rate than expected from measurements in the upper atmosphere. A global circulation model was therefore used to analyze how the smoke is transported from around 80 km altitude and deposited in Greenland and Antarctica, mainly by snow. The model cannot satisfactorily account for either the absolute rate of deposition or the ratio of the deposition rates in the polar regions. A variety of explanations to account for this discrepancy are then explored, including a volcanic artifact in the ice cores, fragmentation of meteoroids, and a temporal change in the cosmic dust input.
Type of Medium:
Online Resource
ISSN:
2169-897X
,
2169-8996
DOI:
10.1002/jgrd.v122.20
DOI:
10.1002/2017JD027143
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
2017
detail.hit.zdb_id:
710256-2
detail.hit.zdb_id:
2016800-7
detail.hit.zdb_id:
2969341-X
SSG:
16,13
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