Acta Geographica Sinica ›› 2023, Vol. 78 ›› Issue (11): 2797-2810.doi: 10.11821/dlxb202311010

• Surface Process • Previous Articles     Next Articles

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

ZHAG Xueqin1(), JIN Zheng2, SHEN Pengke3, ZHENG Du1   

  1. 1. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. Department of Atmospheric and Oceanic Sciences, Fudan University, Shanghai 200438, China
    3. National Climate Center, China Meteorological Administration, Beijing 100081, China
  • Received:2023-07-19 Revised:2023-11-14 Online:2023-11-25 Published:2023-11-29
  • Supported by:
    The Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0202-02);National Natural Science Foundation of China(41471064)

Abstract:

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 non-freezing 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 water-heat 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 lake-air 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.

Key words: lake surface water-heat flux, meteorological factor, eddy covariance, alpine lakes, Yamzhog Yumco