藏东南地区复杂下垫面能量收支特征分析

Analysis on the Features of Energy Budget on the Complicated Underlying Surfaces in Southeast Tibet

利用公益性行业(气象)科研专项项目"藏东南地区复杂下垫面地气交换观测研究"在藏东南地区进行的地气交换观测实验数据,分析典型晴天和阴天条件下不同下垫面能量过程的特征及其差异。结果表明:在典型晴空状态下,不同下垫面的地表净辐射均具有明显的日变化特征,在典型阴天的情况下,不同下垫面地表净辐射日均值显著减小;在典型晴空天气下,4种类型下垫面上潜热均随着净辐射的增加而表现为增加的趋势,在典型阴天的情况下,潜热通量明显比晴空天气小;不同下垫面感热通量的日变化存在显著的差异,不同下垫面感热的变化特征在典型晴空和阴天条件下的差异不明显;不同下垫面土壤热通量与净辐射的变化趋势基本一致,阴天夜晚土壤热流的交换与晴天夜晚的差异不大,四种下垫面土壤均存在能量损失,土壤处于降温状态。

Observation data from the land-atmosphere exchange experiment conducted in Nyingchi Region by the publicservice （weather） scientific research project ＂observation and study on the land-atmosphere exchange on the complicated underlying surfaces in southeast Tibet＂ was applied to analyze the characteristics and differences of surface energy typical on different underlying surfaces in typical sunny days and cloudy days. Results showed that： there is a obvious daily variation of net radiation on different underlying surfaces in typical sunny days, the average daily value of net radiation in typical cloudy days decreased significantly ; latent heat increased with the increasing of net radiation, and it is smaller in cloudy days than in sunny days ; there was a significant difference on the daily variation tendency of sensible heat flux in different underlying surface, but the differences of sensible heat flux between typical sunny days and in typical cloudy days is not obvious; soil heat flux has the same obvious diurnal variation characteristic with net radiation in different underlying surface, the differences of sensible heat flux between night and daytime is not obvious, four kinds of underlying surface soil has energy losses.