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The modern atmospheric background dust load: Recognition in central Asian snowpack, and compositional constraints
Author(s) -
Hinkley Todd,
Pertsiger Felix,
Zavjalova Liliya
Publication year - 1997
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl01533
Subject(s) - snowpack , geology , volcano , asian dust , mineral dust , snow , range (aeronautics) , massif , earth science , atmospheric dust , atmospheric sciences , physical geography , aerosol , geochemistry , geomorphology , geography , meteorology , materials science , composite material
Dusts in strata of snowpack in the Alai‐Pamir range, Kirghizstan, Central Asia, have chemical compositions that are in the same restricted range as those of the dusts found in snowpacks at three other locations: central south Greenland, the St. Elias range (Alaska), and coastal Antarctica, where special‐type local dust sources certainly cannot dominate. This similarity at the four widely separated sites appears to indicate that there is a modern atmospheric background dust that is the same on a regional, hemispheric, or global scale. The common compositional range is that of average crustal rock, or of moderately ferromagnesian volcanic rock. It is not that of carbonate, nor highly siliciceous rocks. Previously, the existence of an atmospheric background dust has been postulated only on the basis of its particle size distribution, and only from observations in polar regions. The present study partially determines the chemical composition of the background dust, and confirms its existence in snowpack at four localities worldwide, including the center of the earth's largest continent where dusts of local source have considerable influence.