Characteristics of land-atmosphere energy and turbulentfluxes over the plateau steppe in central Tibetan Plateau  

作　　者：MaoShan Li ZhongBo Su YaoMing Ma XueLong Chen Lang Zhang ZeYong Hu 

机构地区：[1]Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China [2]Faculty of Geo-Information Science and Earth Observation of the University of Twente,Enschede,The Netherlands [3]Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Research in Cold and Arid Regions》2016年第2期103-115,共13页寒旱区科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 91337212, 41175008);Cold and Arid Regions Environmental and Engineering Research Institute Youth Science Technology Service Network initiative (STS);the China Exchange Project (Grant No. 13CDP007);the National Natural Science Foundation of China (Grant Nos. 40825015 and 40675012)

摘　　要：The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the Tibetan Plateau(TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point(BJ) of the Nagqu Plateau Climate and Environment Station(NPCE-BJ), different characteristics of the energy flux during the Asian summer monsoon(ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energy fluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than that of the post-monsoon period. Footprint modeling shows the distribution of data quality assessments(QA) and quality controls(QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly representative of the target land-use type. The target surface contributed more to the fluxes under unstable conditions than under stable conditions. The main wind directions(180° and 210°) with the highest data density showed flux contributions reaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density, e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance(SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was also explored in this study. The Nash-Sutcliffe model efficiency coefficients(NSEs) of the observed fluxes with the SEWAB model runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of-0.9 for latent heat flux during the post-monsoon period.The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the Tibetan Plateau(TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point(BJ) of the Nagqu Plateau Climate and Environment Station(NPCE-BJ), different characteristics of the energy flux during the Asian summer monsoon(ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energy fluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than that of the post-monsoon period. Footprint modeling shows the distribution of data quality assessments(QA) and quality controls(QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly representative of the target land-use type. The target surface contributed more to the fluxes under unstable conditions than under stable conditions. The main wind directions(180° and 210°) with the highest data density showed flux contributions reaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density, e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance(SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was also explored in this study. The Nash-Sutcliffe model efficiency coefficients(NSEs) of the observed fluxes with the SEWAB model runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of-0.9 for latent heat flux during the post-monsoon period.

关 键 词：turbulent energy flux Asian summer monsoon GAP-FILLING surface energy water balance model central Tibetan Plateau 

分 类 号：P422.4[天文地球—大气科学及气象学]