西藏羊卓雍错湖面水热通量变化及其与气象因子的关联  

Lake surface water-heat flux variation and its correlation with meteorological factors in the Yamzhog Yumco,Tibet

作　　者：张雪芹[1] 靳铮 沈鹏珂 郑度[1] ZHAG Xueqin;JIN Zheng;SHEN Pengke;ZHENG Du(Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;Department of Atmospheric and Oceanic Sciences,Fudan University,Shanghai 200438,China;National Climate Center,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]中国科学院地理科学与资源研究所中国科学院陆地表层格局与模拟重点实验室,北京100101 [2]复旦大学大气与海洋科学系,上海200438 [3]中国气象局国家气候中心,北京100081

出　　处：《地理学报》2023年第11期2797-2810,共14页Acta Geographica Sinica

基　　金：第二次青藏高原综合科学考察研究(2019QZKK0202-02);国家自然科学基金项目(41471064)。

摘　　要：气候变暖背景下湖泊表层水热交换及其气候归因对高寒湖泊蒸发机制和水分平衡有重要影响。本文基于2016—2017年西藏高寒湖泊羊卓雍错非封冻期涡动相关湍流观测通量数据,首次探讨了该湖水热通量小时、日、月变化特征及其与气象因子的关联。研究发现,4—12月羊卓雍错湖面潜热通量平均值显著高于感热通量;水热通量季节差异明显,夏季较高的空气温湿度组合对湖面的湖—气能量交换控制作用显著。在小时、日、月等时间尺度上,与感热通量统计相关性最高的气象因子为湖—气温差;在半小时、日平均等时间尺度上,潜热通量与风速、风速—水汽压差协同量均为较强正相关;日、月平均时间尺度上的湖面水热通量则与水面净辐射通量呈显著负相关,这归因于水面净辐射季节变化以及因湖—气温差和水—气热容量差异所导致的湖面水热通量强度变化的位相差异。本文揭示了藏南高寒湖泊水热通量变化在不同时间尺度上的主控气象因子差异,增进了对高寒湖泊在气候变化背景下能量交换和蒸发机制的认识。Lake surface water-heat exchange and its climatic attribution critically influence the evaporation mechanism and water balance in alpine lakes in a warming climate.Based on the eddy covariance turbulent flux observation of Yamzhog Yumco,an alpine lake in Tibet,this paper explored the characteristics of the hourly,daily,and monthly variations of the lake surface water-heat flux and their correlations with meteorological factors during the nonfreezing period in 2016 and 2017.We found that the average latent heat flux was much higher than the sensible heat flux on the lake surface from April to December.Moreover,the waterheat flux exhibited remarkable seasonal variation,and the higher air temperature and humidity in summer jointly controlled the lake-air energy exchange over the lake surface.First,the lakeair temperature difference was the most significant meteorological factor related to sensible heat flux on half-hourly,daily,and monthly scales.Second,the latent heat flux was strongly positively correlated with wind speed and the synergies of wind speed and water vapor pressure deficit on the daily and half-hourly scales.Third,the lake surface water-heat flux was significantly negatively correlated with the net radiation flux on the daily and monthly scales,which was attributed to the seasonal variation of the water surface net radiation and the phase difference of the water-heat flux intensity change due to the lake-air temperature difference and heat capacity contrast.The results revealed the differences of the main controlling meteorological factors in the variation of water-heat flux in the alpine lakes in south Tibet on different timescales.The work will hopefully improve our understanding of the mechanisms of energy exchange and evaporation over alpine lakes in the future projected climate conditions.

关 键 词：湖面水热通量 主控气象因子 涡动相关 高寒湖泊 羊卓雍错 

分 类 号：P343.3[天文地球—水文科学] P339[天文地球—地球物理学]