青藏高原中部聂荣半干旱草地夏季近地层能量平衡与输送分析  

A Study on Energy Balance and Transfer in the Surface Layer over Semi-Arid Grassland of Nyainrong Area in Central Tibetan Plateau in Summer

作　　者：杨丽薇[1] 高晓清[1] 惠小英[1] 周亚[1,2] 侯旭宏[1] YANG Liwei GAO Xiaoqing HUI Xiaoying ZHOU Ya HOU Xuhong(Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730030 University of Chinese Academy of Sciences, Beijing 100049)

机构地区：[1]中国科学院西北生态环境资源研究院寒旱区陆面过程与气候变化重点实验室,兰州730030 [2]中国科学院大学,北京100049

出　　处：《气候与环境研究》2017年第3期335-345,共11页Climatic and Environmental Research

基　　金：国家自然科学基金项目91437108;科技部公益性行业(气象)科研专项GYHY201406001~~

摘　　要：利用青藏高原中部聂荣地区草地下垫面2014年7~8月近地层气象要素梯度观测及湍流观测数据,分析讨论了该地区观测期间的基本气象要素特征、能量平衡特征以及能量输送特征,主要结论如下:(1)向下、向上短波辐射和净辐射日变化规律一致,向下、向上长波辐射日变化平缓。反照率呈"U"型分布,早晚大,中午小,聂荣夏季地表平均反照率为0.20。(2)在夏季白天,聂荣地区净辐射大部分以潜热的形式加热大气。考虑了土壤浅层热储存和垂直运动引起的平流输送后,能量闭合率由0.65提高到0.80,闭合率有显著的提高。(3)在不稳定层结下,动量总体输送系数CD平均值为4.7×10^(-3)和热量总体输送系数CH平均值为3.5×10^(-3);在稳定层结下,CD平均值为3.4×10^(-3),CH平均值为1.8×10^(-3);C_D和C_H在近中性层结下的平均值分别为4.30×10^(-3)和2.39 10^(-3)。Based on gradient and turbulence data observed in the near surface layer over semi-arid grassland of Nyainrong area in the central Tibetan Plateau from 18 July 2014 to 31 August 2014, characteristics of several basic meteorological elements and energy balance and transfer are analyzed. The main results are： （1） The downward and upward short-wave radiation and net radiation fluxes have a similar diurnal variation pattern, and the diurnal fluctuation of the downward and upward long-wave radiation fluxes are small. The surface albedo shows a ＂U＂ type distribution with large values in the morning and evening and small values in the noon. The mean surface albedo over Nyairong area in summer is 0.20. （2） The latent heat flux is obviously larger than the sensible heat flux, which indicates that the latent heat plays a dominate role in the heat transfer between the atmosphere and surface. The closure rate of surface energy balance increases significantly from 0.65 to 0.80 after considering the heat storage in the shallow soil layer and heat advection caused by vertical movement. （3） The bulk transfer coefficients CD and CH for momentum and heat are 4.7 × 10-3 and 3.5 × 10-3 respectively under unstable stratification; their values are 3.4 × 10-3 and 1.8 × 10-3 under stable stratification, and 4.30 × 10-3 and 2.39× 10-3 under near neutral stratified condition.

关 键 词：青藏高原 半干旱草地 能量平衡 总体输送系数 

分 类 号：P422.4[天文地球—大气科学及气象学]