TY - JOUR
T1 - Influence of the tian shan on arid extratropical Asia
AU - Baldwin, Jane
AU - Vecchi, Gabriel Andres
N1 - Funding Information:
CMAP, GPCP, and University of Delaware precipitation data provided by the NOAA/ OAR/ESRL Physical Sciences Division, Boulder, Colorado, from their website (http://www.esrl.noaa.gov/psd/). University of East Anglia data were provided by their Climate Research Unit from their website (http://www. cru.uea.ac.uk/data). We thank Thomas Delworth, Xiaosong Yang, P.C.D.Milly, and Isaac Held for helping conceptualize this project, and for useful comments and discussion.We also thank Seth Underwood for his crucial technical support. Finally, we are grateful for insightful comments from John Chiang and another anonymous reviewer. JWB was supported by the National Science Foundation Graduate Research Fellowship under Grant DGE 1148900. This work was partially supported by the NOAA Climate Program Office.
Publisher Copyright:
© 2016 American Meteorological Society.
PY - 2016
Y1 - 2016
N2 - Arid extratropical Asia (AEA) is bisected at the wetter Tian Shan (a northern offshoot of the Tibetan Plateau) into east and west deserts, each with unique climatological characteristics. The east deserts (~35°- 55°N, ~75°-115°E) have a summer precipitation maximum, and the west deserts (~35°-55°N, ~45°-75°E) have a winter-spring precipitation maximum. A new high-resolution (50 km atmosphere-land) global coupled climate model is run with the Tian Shan removed to determine whether these mountains are responsible for the climatological east-west differentiation of AEA. Multicentennial simulations for the Control and NoTianshan runs highlight statistically significant effects of the Tian Shan. Overall, the Tian Shan are found to enhance the precipitation seasonality gradient across AEA, mostly through altering the east deserts. The Tian Shan dramatically change the precipitation seasonality of the Taklimakan Desert directly to its east (the driest part of AEA) by blocking west winter precipitation, enhancing subsidence over this region, and increasing east summer precipitation. The Tian Shan increase east summer precipitation through two mechanisms: 1) orographic precipitation, which is greatest on the eastern edge of the Tian Shan in summer, and 2) remote enhancement of the East Asian summer monsoon through alteration of the larger-scale seasonal mean atmospheric circulation. The decrease in east winter precipitation also generates remote warming of the Altai and Kunlun Shan, mountains northeast and southeast of the Tian Shan, respectively, due to reduction of snow cover and corresponding albedo decrease.
AB - Arid extratropical Asia (AEA) is bisected at the wetter Tian Shan (a northern offshoot of the Tibetan Plateau) into east and west deserts, each with unique climatological characteristics. The east deserts (~35°- 55°N, ~75°-115°E) have a summer precipitation maximum, and the west deserts (~35°-55°N, ~45°-75°E) have a winter-spring precipitation maximum. A new high-resolution (50 km atmosphere-land) global coupled climate model is run with the Tian Shan removed to determine whether these mountains are responsible for the climatological east-west differentiation of AEA. Multicentennial simulations for the Control and NoTianshan runs highlight statistically significant effects of the Tian Shan. Overall, the Tian Shan are found to enhance the precipitation seasonality gradient across AEA, mostly through altering the east deserts. The Tian Shan dramatically change the precipitation seasonality of the Taklimakan Desert directly to its east (the driest part of AEA) by blocking west winter precipitation, enhancing subsidence over this region, and increasing east summer precipitation. The Tian Shan increase east summer precipitation through two mechanisms: 1) orographic precipitation, which is greatest on the eastern edge of the Tian Shan in summer, and 2) remote enhancement of the East Asian summer monsoon through alteration of the larger-scale seasonal mean atmospheric circulation. The decrease in east winter precipitation also generates remote warming of the Altai and Kunlun Shan, mountains northeast and southeast of the Tian Shan, respectively, due to reduction of snow cover and corresponding albedo decrease.
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U2 - 10.1175/JCLI-D-15-0490.1
DO - 10.1175/JCLI-D-15-0490.1
M3 - Article
AN - SCOPUS:84983483139
SN - 0894-8755
VL - 29
SP - 5741
EP - 5762
JO - Journal of Climate
JF - Journal of Climate
IS - 16
ER -