GAME/Tibet实验中感热通量计算方法的讨论

摘要

Based on previous research on sensible heat flux, we investigate it from different aspects usingGAME/Tibet data measured during 6 June-13 September, 1998. This work consists of the derivationof the surface heat flux equation, analysis on counter-gradient heat transference, comparison betweentwo different methods to compute the sensible heat flux, and investigation on the calculation scheme ofsensible heat flux in the Simple Biosphere model 2 (SiB2) with relevant simulation. By improving twoprevious formulations, an integrated formulation for calculating surface heat flux is given. Secondly, usingthe measured data, the counter-gradient heat flux is clarified, leading to the fact that buoyancy plays animportant role in the sensible heat transfer process. It is concluded that (1) energy imbalance is a commonphenomenon resulting from the use of the traditional closure scheme on the heterogeneous underlyingsurface because the measured ensemble heat fluxes by eddy correlation contain the effect of nonlocal parcelmovements; and (2) nonlocal parcel movement deserves more attention in any future heat flux study.%回顾了前人对感热通量的分析研究,详细分析了计算感热通量公式的推导过程.结合GAME/Tibet那曲近地面通量观测站1998年6月6日到9月13日的观测资料验证了近地面层逆梯度热输送现象的存在;并比较了两种不同计算感热通量的方法.同时,对简化生物圈模式(SiB2)计算感热通量方案进行了分析.主要结论有:(1)由于用涡旋相关法测量得到的总体感热通量本身已经包含了非局地热(冷)泡运动的影响,所以在非均匀下垫面上,传统的闭合方案必然会"遭遇"能量不平衡.这里,非均匀下垫面可能是导致能量不平衡的关键所在.(2)在今后的有关热通量研究中,有必要仔细研究非局地热(冷)泡运动对热通量的贡献,而为了更好地理解这种贡献,应用陆面过程模式研究能量平衡是必需的.