Page 110 - 《高原气象》2025年第6期

高 原 气 象 44 卷
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The Impact of Plateau Sensible Heat on the Plateau Monsoon

Based on Station Observations

LI Yixin， ZHANG Shaobo， ZHAO Yong， YANG Xianyu
（College of Atmospheric Sciences， Chengdu University of Information Technology / Sichuan Key Laboratory of Plateau
Atmosphere and Environment / Chengdu Plain Urban Meteorology and Environment Sichuan Province Field Scientific
Observation Research Station / Sichuan Province Laboratory of Meteorological Disaster Forecast and
Warning Engineering， Chengdu 610225， Sichuan， China）

Abstract： To investigate the relationship between sensible heat （SH） over the Qinghai-Xizang Plateau （QXP）
and TP monsoon dynamics， this study employs station-derived SH data （1979 -2016） alongside ERA5 reanaly‐
sis datasets to compute multiple QXP monsoon indexes. Using correlation and composite analyses， the spatiotem‐
poral variability and interactions between SH and monsoon systems were explained. The primary findings are
summarized as follows： （1） The two monsoon indexes （IPM and IPM zhang ） exhibit divergent temporal respons‐
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es to SH variability， attributable to their distinct definitions. Summer SH and summer monsoon intensity show a
significant negative correlation with IPM zhang （r=−0. 30， p<0. 1） but only a weak， statistically insignificant corre‐
lation with IPM . Conversely， May SH correlates positively with summer IPM （r=0. 32， p<0. 1） and nega‐
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tively with summer IPM zhang （r=−0. 44， p<0. 01）， underscoring May SH’s critical role in preconditioning mon‐
soon intensity.（2） For summer SH and monsoon interactions， IPM reveals an east-west dipole spatial correla‐
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tion with SH， whereas IPM zhang displays a north-south contrast. Despite regional disparities， both indexes align
with monsoon-precipitation linkages， reflecting soil moisture feedback that suppresses SH through monsoon-
driven precipitation.（3） Elevated May SH across the southern QXP initiates an upper-tropospheric anomalous
low-pressure system over the central QXP in summer， generating a midlatitude “− + − + −” wave train. Coupled
with a low-level ascending vertical structure and anomalous mid-upper tropospheric pressure systems， these dy‐
namics establish a synergistic thermodynamic framework conducive to precipitation in the southeastern QXP. A
600 hPa anomalous low-pressure system over the southeastern QXP and intensified westerlies over the northern
QXP further strengthen IPM while weakening IPM zhang ， demonstrating May SH’s pivotal influence on summer
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monsoon modulation.
Key wrods： Qinghai-Xizang Plateau； Plateau sensible heat； Plateau Monsoon； precipitation