Premium
Large‐Scale Dynamics and Moisture Sources of the Precipitation Over the Western Tibetan Plateau in Boreal Winter
Author(s) -
Liu Xiaolin,
Liu Yimin,
Wang Xiaocong,
Wu Guoxiong
Publication year - 2020
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2019jd032133
Subject(s) - climatology , teleconnection , anticyclone , middle latitudes , westerlies , troposphere , plateau (mathematics) , boreal , subtropics , precipitation , cyclone (programming language) , environmental science , north atlantic oscillation , atmospheric sciences , geology , el niño southern oscillation , geography , meteorology , biology , mathematical analysis , paleontology , mathematics , field programmable gate array , fishery , computer science , computer hardware
One of the heaviest precipitations over the Asian continent in winter is located in the western Tibetan Plateau (TP). In this study, the dynamics of the precipitation over the western TP (PWTP) in boreal winter and its interannual variability are explored. The moisture origins and paths are detected using a Lagrangian Integrated Trajectory model. In climatology, the PWTP is generated as results of upward air motions on the windward side of the TP and ranges from 0.5 to 2.5 mm·day −1 . Under the influence of midlatitude westerlies and the subtropical high over the Arabian Peninsula, three key moisture sources (by percentage contribution) are identified: South Asia‐North Indian Ocean (56.6%), Central Eurasia‐North Africa (37.7%), and Central‐North Atlantic (5.6%). The dominant precipitating cloud types are nimbostratus and stratus/stratocumulus derived from satellite data. On the interannual timescale, PWTP variation is closely associated with El Niño‐Southern Oscillation (ENSO) and midlatitude cyclones. ENSO warm events lead to an anomalous anticyclone over the tropical northwest Indian Ocean and intensify moisture transport northward in the lower troposphere, as well as abnormal divergence in upper troposphere. However, ENSO explains only about 38.1% of the PWTP variance. Midlatitude teleconnection also contributes to the PWTP variability, which is comparable to the effect of ENSO. The cyclones imbedded in the subtropical jet are part of the teleconnection, with an anticyclone upstream over the North Atlantic and an cyclone over the western TP. Further evidence suggests that the transient eddies in the North Atlantic help to maintain the teleconnection.