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Atmospheric Dynamics Patterns in Southern Central Asia Since 800 ka Revealed by Loess‐Paleosol Sequences in Tajikistan
Author(s) -
Lu Hao,
Jia Jia,
Yin Qiuzhen,
Xia Dunsheng,
Gao Fuyuan,
Liu Hao,
Fan Yijiao,
Li Zaijun,
Wang Xin,
Berger André,
Oimuhammadzoda Ilhomjon,
Gadoev Mustafo
Publication year - 2020
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 - 10.1029/2020gl088320
Subject(s) - loess , westerlies , geology , atmospheric circulation , interglacial , climatology , southern hemisphere , grain size , glacial period , paleosol , atmospheric sciences , physical geography , geomorphology , geography
The atmospheric mechanisms responsible for the loess grain‐size variations in central Asia are less clear, and an increasing number of studies have found that the coarse‐grained component is likely supplied by the surface circulation rather than by the westerlies (westerlies circulation). In this study, we attempt to determine the atmospheric dynamics patterns in the Afghan‐Tajik Basin during the past 800 kyr, based on the coarse grain‐size fraction of loess, combined with a study of modern dust transport processes. We suggest that the coarse grain‐size fraction can be used to indicate the intensity of near‐surface winds, while on glacial‐interglacial time scales, the variations of loess grain size in Tajikistan are dominated by Northern Hemisphere ice volume via its effect on the strength of the Siberian High. In addition, we suggest that atmospheric greenhouse gases concentration affected the loess grain size during interglacials via their influence on the temperature of southern high latitudes.