青藏高原及周边地区近地层气候要素特征分析  

Analysis of Climate Characteristics of Near-surface Layer over TibetanPlateau and Its Surrounding Areas

作　　者：李英[1,2] 卢萍 赵兴炳[1,2] LI Ying;LU Ping;ZHAO Xingbing(Institute of Plateau Meteorology,China Meteorological Administration,Chengdu 610072,China;Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China)

机构地区：[1]中国气象局成都高原气象研究所,四川成都610072 [2]高原与盆地暴雨旱涝灾害四川省重点实验室,四川成都610072

出　　处：《沙漠与绿洲气象》2023年第2期81-90,共10页Desert and Oasis Meteorology

基　　金：高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金项目(SCQXKJYJXMS202216);第二次青藏高原综合科学考察研究项目(2019QZKK0103,2019QZKK0105)。

摘　　要：利用中国气象局成都高原气象研究所建立的5个边界层站(湄潭、巴中、什邡、曲麻莱、狮泉河)2019年的观测资料,对比分析青藏高原及周边地区近地层大气要素变化和陆—气能量交换特征及异同点,探讨其原因。结果表明:(1)青藏高原及周边地区近地层大气温度、相对湿度、风速、感热通量、潜热通量、动量通量均符合一峰一谷的常规日变化特征,气压具有双峰双谷的日变化特征。(2)高海拔台站近地层温度日变幅(12℃)高于周边低海拔地区(4~6℃),季变幅与海拔高度的关系不显著。(3)相对湿度与温度关系密切,相对湿度的垂直结构和日变化都具有明显的区域差异,其垂直梯度夜间显著高于白天,峰值出现时间随夏、秋、春、冬季呈现季节性滞后,而谷值超前。(4)风速春季较大,夏、秋季次之,冬季小,季变幅略小于日变幅;低海拔区域的风速及其日变幅均显著低于高海拔区域。(5)低海拔区域气压季变幅(>13 hPa)远高于日变幅(2.5 hPa左右),而高海拔区域气压季变幅(>3 hPa)略低于日变幅(2 hPa左右)。(6)感热通量春季大、冬季小;感热通量和动量通量在高海拔区域均较高,二者具有较一致的日、季变化特征,表明大气动力因子对于陆—气过程感热交换起着重要的作用;潜热通量夏季高、冬季低,与海拔高度关系不明显,主要由测站所在位置、温度、湿度、地形、地貌等因素共同决定。Based on the observational data of five boundary layer stations(Meitan,Bazhong,Shifang,Qumalai and Shiquanhe)established by Institute of Plateau Meteorology,China Meteorological Administration in 2019,the characteristics and differences of atmospheric elements and energy exchange between land-air in this area are compared and analyzed,and the reasons are discussed.The results show that:(1)The diurnal variation of air temperature,relative humidity,wind speed,sensible heat flux,latent heat flux and momentum flux in the surface layer of the Qinghai-Tibet Plateau and its surrounding area shows the conventional characteristics of single peak and single valley,but atmospheric pressure appears the characteristics of double peaks and double valleys.(2)The daily variation amplitude of surface temperature in the high altitude stations(12℃)is much higher than that in the surrounding low altitude area(4-6℃),and the relationship between the seasonal variation and the altitude is not significant.(3)Relative humidity is closely related to temperature,and the vertical structure and daily variation characteristic of relative humidity have obvious regional differences.The vertical gradient at night is significantly higher than that during the day,and the time of peak value of relative humidity is seasonally delayed with summer,autumn,spring and winter,while the valley value is ahead.(4)The wind speed is higher in spring,followed by summer and autumn,smaller in winter,and its seasonal variation is slightly smaller than the daily variation.The wind speed and amplitude in low altitude area are significantly lower than those in the high altitude area.(5)The seasonal variation of pressure in low altitude area(more than 13 hPa)is much higher than the diurnal variation(about 2.5 hPa),while the seasonal variation of pressure in high altitude area(more than 3 hPa)is slightly lower than the diurnal variation(about 2 hPa).(6)The sensible heat flux is affected by surface temperature difference,wind speed,relative humidity and net radiatio

关 键 词：青藏高原 近地层 日变化 梯度 湍流输送 

分 类 号：P482.1[天文地球—大气科学及气象学]