帕米尔高原近地层气象要素垂直变化特征

Vertical Variations of the Near-surface Layer Meteorological Element Profile in Pamirs

利用中国与巴基斯坦交界的红其拉甫口岸帕米尔高原陆气相互作用观测站32 m梯度铁塔资料,分析了帕米尔高原在不同天气下近地层气温、湿度和风速等气象要素廓线日变化和脉动特征,结果表明:(1)晴天,日间风速随高度升高而增大,夜间风速随高度升高呈波动减小;阴雨天,风速整体随高度升高而增大;不同天气下各高度层脉动风速概率分布均呈现高度越高,脉动风速分布越集中的特征。(2)气温廓线在晴天表现为夜间辐射型、早上过渡型、白天日射型和傍晚过渡型四种类型,气温脉动随着高度的降低而增大;阴雨天气时气温廓线均为白天日射型,各高度层的气温脉动变化特征与晴天相反。(3)不同天气的比湿廓线分布均随高度增加而减小,比湿脉动范围晴天大于阴雨天,且在时间序列上波动性均具有一致性。

Based on the 32 m gradient tower data of the Pamir Plateau Land-Atmosphere Interaction Observation Station at Khunjerab Port,which is located at the junction of China and Pakistan,this paper analyzes the diurnal variation and fluctuation characteristics of meteorological elements such as surface temperature,humidity and wind speed in the Pamir Plateau under different weather conditions.The results show that:(1)In clear days,the daytime wind speed increases with height,while the nighttime wind speed decreases with the increase in height.Besides,the wind speed increases with altitude in rain-cloudy days.The law of higher the altitude,more concentrated the fluctuated wind speed distribution is presented in the fluctuated wind speed frequency distribution at various altitudes under different weather conditions.(2)Under clear conditions,the temperature profile is divided into four types:night radiation,morning transition,day-time insolation,and evening transition.The temperature pulsation increases with the decrease in altitude.The temperature profiles under rain-cloudy weather are all of day-time insolation type,and the fluctuation characteristics of temperature in each high layer are opposite to that in sunny days.(3)The specific humidity profile distribution under different weather conditions decreases with the increase in height.In addition,the specific humidity pulsation range is larger in sunny days than in cloudy and rainy days,and the fluctuation in time series are consistent.