摘要
为了揭示云南低纬高原地区冬季气温变化的主要特征及影响的关键环流因子,本文利用云南124站地面气象站月平均气温观测资料、NCEP/NCAR大气环流再分析资料,以及CPC和NCC提供的部分大气遥相关型和环流特征指数,首先分析了云南冬季气温变化的主要特征,表明冬季气温年际变率东部大于西部,主要空间分布有全区一致、东西差异、经向三级差异、西北-东南差异四种型态,前四个模态占EOF总方差贡献的90%,其中前三个模态线性变化趋势明显,第四模态主要表现出显著的年代际波动特征。分析发现相应不同气温模态,中高纬度异常波列呈现出明显不同的形势和走向,与500 hPa中高纬度异常波列相关的四个关键区的高度异常,以及孟加拉湾地区的高低层环流异常对气温主要模态有十分重要的影响:第一模态与东亚中低纬度南(20°N-30°N,90°E-120°E)北(45°N-60°N,90°E-120°E)两个区域经向差异密切联系,北低南高(北高南低)形势有利于全区一致偏暖(冷);第二模态与中高纬度纬向波列有关,当东亚-西北太平洋区域(25°N-45°N,120°E-160°E)高度偏高(低)、700 hPa孟加拉湾北部区域(15°N-25°N,80°E-100°E)气旋(反气旋)活动、300 hPa东南亚纬向风切变Uwnd-shear-300大于(小于)零时,有利于气温西冷东暖(西暖东冷);第三模态与中高纬度西北-东南向波列有关,高原区域(30°N-50°N,80°E-110°E)高度偏高(低)有利于气温中冷东西暖(中暖东西冷)经向三级模态;第四模态主要受孟加拉湾区域高低层局地环流变化的影响。气温模态与大气遥相关型和关键环流系统指数的相关进一步表明了中高纬度异常波列的重要作用,同时表明了高原高度场也是影响云南冬季气温变化的重要的因子之一。
To reveal the main characteristics of winter temperature change in Yunnan and the key circulation factors affecting on it,the winter temperature variation is first investigated by using monthly mean temperature data of 124 meteorological observation stations in Yunnan,NCEP/NCAR reanalysis data,some atmospheric teleconnection indices and atmospheric circulation characteristic indices provided by CPC(Climate Prediction Center)and NCC(National Climate Center).The results show that the annual variability of winter temperature is more obvious in the East than that in the West.There are four dominant EOF patterns of winter temperature in Yunnan,i.e.the whole regional consistent pattern,the East-West difference pattern,the meridional triple-like pattern and the northwest-southeast difference pattern.The four dominant patterns account for 90%of the EOF total variance contribution.The interannual changes of the first three patterns show a significant linear trend,but the fourth pattern mainly shows interdecadal fluctuation characteristics.It is found that the situation and trends of wave train in mid-high latitude regions is obvious different corresponding to different temperature patterns.The geopotential height in four key areas related to the anomalous wave trains in mid-high latitude regions at 500 hPa,as well as the atmospheric circulation anomalies in low-high level in the Bay of Bengal(BOB),have a very important impact on the temperature patterns.The first EOF pattern is closely related to geopotential height difference between in the southern(20°N-30°N,90°E-120°E)and Northern(45°N-60°N,90°E-120°E)East Asia.When the geopotential height is low in Southern and high in Northern,the temperature is uniform warming,and vice versa.The second pattern is related to the zonal wave trains in the mid-high latitude regions.When the geopotential height from East Asia to Northwest Pacific region(15°N-25°N,80°E-100°E)is high(low),there is a cyclone(anticyclone)occur in 700 hPa in the northern BOB(15°N-25°N,80°E-100�
作者
晏红明
王灵
金燕
马思源
黎文懋
万云霞
YAN Hongming;WANG Ling;JIN Yan;MA Siyuan;LI Wenmao;WAN Yunxia(Yunnan Province climate center,Kunming 650034,Yunnan,China;Yunnan Province bureau,Kunming 650034,Yunnan,China;Yunnan meteorological science and technology service center,Kunming 650034,Yunnan,China)
出处
《高原气象》
CSCD
北大核心
2023年第2期386-402,共17页
Plateau Meteorology
基金
国家自然科学基金项目(U1902209,41775073)
西南区域重点项目(2014-4)。
关键词
云南冬季气温
主要模态
关键环流因子
中高纬度波列
高原高度场
孟加拉湾环流
西伯利亚高压
Winter temperature in Yunnan
dominant patterns
key circulation factors
wave train in mid-high latitude
geopotential height over plateau
BOB cyclone
Siberian High
