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What Distinguishes Summer Extreme Precipitation From Non‐Extreme Precipitation Over the Tibetan Plateau?

Authors :
Ding, Zhiyuan
Ha, Yao
Huangfu, Jingliang
Zhong, Zhong
Source :
Geophysical Research Letters; 10/28/2024, Vol. 51 Issue 20, p1-11, 11p
Publication Year :
2024

Abstract

This study focuses on the primary synoptic‐scale patterns and precursors of extreme and non‐extreme precipitation over the Tibetan Plateau (TP). Atmospheric circulation anomalies and their precursors associated with regional extreme precipitation events (REPE) demonstrate distinct precursor wave train and heightened intensity than regional non‐extreme precipitation events (non‐REPE). Specifically, REPE over the northwestern TP (NWTP) exhibits a geopotential height anomaly induced by a latitudinal propagating Rossby wave train along 40°N. In contrast, over the southeastern TP (SETP), REPE is characterized by a geopotential height anomaly caused by a northwest‐southeastward propagating Rossby wave train. The ascending motion anomalies of REPE over both NWTP and SETP are primarily attributed to the geostrophic zonal temperature advection, which is significantly stronger during REPE compared to non‐REPE. This finding provides valuable insights for forecasting summer extreme precipitation over TP. Plain Language Summary: Tibetan Plateau (TP) is experiencing warming and increased humidity in the context of climate change, leading to a rise in extreme precipitation events. This study focuses on analyzing the circulation patterns and precursors associated with summer extreme precipitation over TP, aiming to identify differences between extreme and non‐extreme precipitation events, as well as explaining the unique characteristics of summer extreme precipitation over TP to answer the question of what distinguishes summer extreme precipitation from non‐extreme precipitation over TP. The findings suggest that summer regional extreme precipitation events (REPE) over the northwest and southeast TP (NWTP and SETP, respectively) display distinct characteristics in terms of atmospheric circulation anomalies and their precursors, which are significantly stronger compared to regional non‐extreme precipitation events (non‐REPE) of varying intensities observed in these two regions. The ascending motion (ω) anomalies responsible for TP's REPE are primarily influenced by the Laplacian of geostrophic zonal temperature advection (term B‐x). Key Points: The extreme precipitation characteristics of the NWTP and SETP, as well as the atmospheric circulation patterns influencing them, exhibit significant disparitiesCirculation anomalies associated with extreme precipitation exhibit a stronger and more distinct precursor wave train, compared to non‐extreme precipitationThe dominant factor driving ascending motion for extreme precipitation over TP is the geostrophic zonal temperature advection [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00948276
Volume :
51
Issue :
20
Database :
Complementary Index
Journal :
Geophysical Research Letters
Publication Type :
Academic Journal
Accession number :
180561888
Full Text :
https://doi.org/10.1029/2024GL111192