Influence of Central Siberian Snow-Albedo Feedback on the Spring East Asian Dust Cycle and Connection With the Preceding Winter Arctic Oscillation

The Asian dust cycle has significant effects on the climate and environment, while its spatiotemporal variability and change mechanisms are not yet completely understood. Reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA2), data set are used t...

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Bibliographic Details
Published in:Journal of Geophysical Research: Atmospheres
Main Authors: Liu, Heng, Liu, Xiaodong, Dong, Buwen
Format: Report
Language:English
Published: AMER GEOPHYSICAL UNION 2018
Subjects:
East Asia
dust cycle
snow-albedo feedback
cloud-albedo feedback
Arctic Oscillation
SAHARAN AIR LAYER
TIBETAN PLATEAU
COVER VARIABILITY
STORM FREQUENCY
CLIMATE-CHANGE
PART II
EMISSION
PRECIPITATION
REANALYSIS
VEGETATION
Meteorology & Atmospheric Sciences
Arctic
albedo
Climate change
Siberia
Online Access:http://ir.ieecas.cn/handle/361006/14428
https://doi.org/10.1029/2018JD029385
Description
Summary:The Asian dust cycle has significant effects on the climate and environment, while its spatiotemporal variability and change mechanisms are not yet completely understood. Reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA2), data set are used to explore the spatiotemporal distribution of the East Asian dust cycle and possible reasons for the interannual variations. Based on the empirical orthogonal function analysis, the dominant mode of dust emissions from the East Asian deserts in the dust season (spring) shows that the Gobi Desert contributes most of the interannual variance of dust emissions in East Asia. The patterns of the regional circulation, temperature, and radiation are analyzed by regressing these variables against the principal component time series of the first empirical orthogonal function mode. The results show that the enhanced dust emissions are associated with a cyclonic circulation anomaly and cooling in the lower and middle troposphere over Central Siberia. The cooling is attributed to local snow-albedo and cloud-albedo feedbacks. The surface cooling is conducive to maintain the snow cover, whereas the cooling in the middle troposphere is associated with the increase of the relative humidity and cloud cover. The increased snow and cloud cover reflect more shortwave radiation, tending to maintain or amplify the surface cooling. It is also found that the negative phase of the Arctic Oscillation in winter initiates the surface cooling in the next spring and results in positive snow-albedo and cloud feedbacks in Central Siberia, eventually enhancing the East Asian dust cycle.

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