MODERN EOLIAN DUST DEPOSITION IN CENTRAL-ASIA

Citation
Cp. Wake et al., MODERN EOLIAN DUST DEPOSITION IN CENTRAL-ASIA, Tellus. Series B, Chemical and physical meteorology, 46(3), 1994, pp. 220-233
Citations number
NO
Categorie Soggetti
Metereology & Atmospheric Sciences
ISSN journal
02806509
Volume
46
Issue
3
Year of publication
1994
Pages
220 - 233
Database
ISI
SICI code
0280-6509(1994)46:3<220:MEDDIC>2.0.ZU;2-U
Abstract
Glaciers around the globe provide a unique medium for investigating th e temporal and spatial variation of dust deposition. Here we investiga te the spatial and seasonal distribution of eolian dust deposition in central Asia through the analysis of concentrations and size distribut ions of insoluble particles (over the size range 1-22 mum diameter) in snow and ice samples collected from eight glaciers in the mountains o f central Asia. The sample locations cover a wide geographic area and fall within 4 distinct landscape/climate zones: the southern slopes of the eastern Himalaya; the Karakoram; south eastern Tibetan Plateau; n orthern/western Tibetan Plateau. Snow samples from each of the 4 lands cape/climatic zone displays distinct dust deposition characteristics w hich are dependent upon the physiographic location of the sampling sit e with respect to source regions of dust and atmospheric transport pat hways. The southern slopes of the eastern Himalaya show very low parti cle concentrations and low annual dust deposition. This region is rela tively free from the influence of Asian dust. The Karakoram appears to be a major sink for particles less than 2 mum in diameter which have been transported long distances with the westerly jet stream. Glaciers in the south eastern Tibetan Plateau record the influx of dust genera ted in the arid and semi-arid regions to the west. Glaciers on the nor thern and western margin of the Tibetan Plateau lie adjacent to vast a rid and semi-arid regions of western China and provide dust depostion records mainly of local significance. Our results suggest that high el evation glaciers in the eastern Himalaya, Karakoram and the south east ern Tibetan Plateau are those most likely to provide longer term dust deposition records which reflect regional to hemispheric signals.