基于台站观测资料的高原感热对高原季风影响研究
网络出版日期: 2025-04-29
基金资助
国家自然科学基金青年项目(42105034);第二次青藏高原综合科学考察研究项目(2019QZKK0103);四川省自然科学基金项目(2025ZNSFSC0332);四川省气象局重点创新团队项目(SCQXTD202402)
The Impact of Plateau Sensible Heat on the Plateau Monsoon Based on Station Observations
Online published: 2025-04-29
为了研究高原感热与高原季风之间的关系,本文使用 1979-2016 年站点感热资料和 ERA5(EC‐MWF Reanalysis V5)再分析资料,计算不同高原季风指数,并利用相关分析与合成分析方法对高原感热和高原季风的变化特征和相关关系进行分析,探讨高原感热对高原季风的影响。结果表明:(1)IPMtang和IPMzhang两种高原季风指数因定义角度不同导致对高原感热的响应存在显著时效性差异,其中对于夏季高原季风与夏季感热的关系,IPMzhang呈显著负相关(r=-0. 30,p<0. 1),而IPMtang呈弱的负相关但不显著;对于夏季高原季风与5月感热的关系,IPMtang呈显著正相关(r=0. 32,p<0. 1),IPMzhang呈显著负相关(r=-0. 44,p<0. 01),反映了 5月感热对于高原季风强弱的影响。(2)对于夏季感热和夏季高原季风的空间相关分布特征,IPMtang为东西反向,而 IPMzhang则呈南北相反。尽管不同指数反映的相关区域存在差异,但均可以与季风和降水的相关性有效对应,反映了季风活动下,因为降水所带来的土壤湿度变化后,对高原感热的抑制作用。(3)对于5月感热而言,5月高原南部感热偏强时,会激发夏季对流层高层高原主体异常低压系统以及中纬度“-+-+-”型波列生成,配合低层上升的垂直结构以及对流层中高层的异常高低压系统,为高原东南部降水提供动力-热力协同作用,促进该地区的降水生成。600 hPa上高原东南部的异常低压系统和高原北部的异常西风分量,也分别有利于 IPMtang的偏强与 IPMzhang的偏弱,揭示了5月感热对于夏季季风活动的影响。
李义鑫, 张少波, 赵 勇, 杨显玉 . 基于台站观测资料的高原感热对高原季风影响研究 [J]. 高原气象, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00045
To investigate the relationship between sensible heat(SH)over the Tibetan Plateau(TP)and TP monsoon dynamics,this study employs station-derived SH data(1979-2016)alongside ERA5 reanalysis datasets to compute multiple TP monsoon indexes. Using correlation and composite analyses,the spatiotemporal variability and interactions between SH and monsoon systems were explained. The primary findings are summarized as follows:(1)The two monsoon indexes(IPMtang and IPMzhang)exhibit divergent temporal responses 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 correlation with IPM tang. Conversely,May SH correlates positively with summer IPMtang(r=0. 32,p<0. 1)and negatively with summer IPM zhang(r=-0. 44,p<0. 01),underscoring May SH’s critical role in preconditioning monsoon intensi‐ ty.(2)For summer SH and monsoon interactions,IPMtang reveals an east-west dipole spatial correlation with SH,whereas IPMzhang 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 TP initiates an upper-tropospheric anomalous low-pressure system over the central TP in summer,generating a midlatitude“- + - + -”wave train. Coupled with a low-level ascending vertical structure and anomalous mid-upper tropospheric pressure systems,these dynamics establish a synergistic thermodynamic framework conducive to precipitation in the southeastern TP. A 600 hPa anomalous low-pressure system over the southeastern TP and intensified westerlies over the northern TP further strengthen IPM tang while weakening IPMzhang,demonstrating May SH’s pivotal influence on summer monsoon modulation.
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