春季青藏高原感热异常对副热带东北太平洋低云的影响
Impact of Sensible Heat Flux Anomaly over Qinghai-Tibet Plateau on Low Cloud Amount over the Subtropical Northeastern Pacific
何维帅 1龙景超 2朱陵晶 2庄淑淇 1徐海 1张树钦 1薛宇峰 2徐建军2
作者信息
- 1. 广东海洋大学海洋与气象学院/南海海洋气象研究院,广东 湛江 524088
- 2. 广东海洋大学海洋与气象学院/南海海洋气象研究院,广东 湛江 524088;中国气象局-广东海洋大学南海海洋气象联合实验室,广东 湛江 524088;广东省高等学校陆架及深远海气候、资源与环境重点实验室,广东 湛江 524088;广东省近海海洋变化与灾害预警实验室,广东 湛江 524088
- 折叠
摘要
[目的]探究春季青藏高原感热异常对同期副热带东北太平洋(Subtropical Northeastern Pacific,SNEP)低云量的影响.[方法]基于卫星观测和再分析资料,采用回归分析、相关分析、合成分析以及模式模拟等方法,分析青藏高原感热与SNEP低云量的关系.[结果与结论](1)青藏高原感热和SNEP低云量奇异值分解的第一模态方差贡献率为33.76%,时间序列相关系数达0.84.(2)春季青藏高原地表感热异常增加时,大气环流异常自青藏高原到SNEP呈现"+-+-+"的准正压波列状结构.SNEP异常反气旋环流会加强北太平洋副热带高压强度,使其向东北移动.同时,异常正压反气旋环流加强下沉运动,大气低层逆温层强度加强,低云高度降低.(3)反气旋环流东南侧的东北风异常加速背景风速,导致海表感热增加,海气界面稳定度减弱,湍流混合运动加强,因此有利于海面向云层输送水汽,促使低云量增加.(4)青藏高原感热异常强年的响应显著大于弱年,体现不对称性.本研究探究青藏高原与SNEP低云变异的物理联系,可为SNEP低云的预测提供参考.
Abstract
[Objective]To investigate the influence of Qinghai-Tibet Plateau(QTP)sensible heat flux anomaly on the low cloud amount over the Subtropical Northeastern Pacific(SNEP)in spring.[Method]Based on satellite observations and reanalysis data,linear regression,correlation analysis,composite analysis and numerical model simulation were used to analyze the relationship between QTP sensible heat flux and SNEP low cloud amount.[Result and Conclusion](1)The variance of leading mode of singular value decomposition between the QTP sensible heat flux and SNEP low cloud amount is 33.76%,and the correlation coefficient between the two time series is 0.84.(2)Strengthened surface sensible heat in spring can generate a barotropic wave train from QTP to the SNEP,presenting an atmospheric circulation anomalies like"+-+-+".The anomalous anticyclonic circulation on the SNEP intensifies the subtropical high in the North Pacific and then shift northeastward.Meanwhile,the anomalous barotropic anticyclone strengthens the downward motion and low level inversion strength,reducing low cloud height.(3)The increased northeasterly winds on the southeast flank of the anticyclone intensifies the prevailing northeasterly,leading to an increase in surface sensible heat,a reduction in the atmospheric stability at air-sea interface,and an enhancement of turbulent mixing.As a result,increased water vapor supply facilitates low cloud formation.(4)The composite analysis reveals an asymmetric response between anomalous strong and weak years.This study discusses the physical relationship between QTP sensible heat flux anomaly and SNEP low cloud changes,which could be a potential reference for the low cloud prediction over the SNEP.
关键词
青藏高原/副热带东北太平洋/低云/感热/大气环流Key words
Qinghai-Tibet Plateau/subtropical Northeast Pacific/low cloud/sensible heat flux/atmospheric circulation引用本文复制引用
基金项目
国家自然科学基金青年基金(41905006)
青藏高原综合科学考察研究项目(第二次)(2019QZKK0105)
广东省教育厅创新团队项目(2023KCXTD015)
广东海洋大学科研启动基金(R19018)
国家自然科学基金(72293604)
出版年
2024
国家科技期刊平台
NSTL
万方数据