夏季不同天气条件下沙漠辐射和能量平衡的对比分析  

Comparative Analysis of Radiation and Energy Budget over Badain Jaran Desert on Clear and Cloudy Days in Summer

作　　者：李建刚[1,2] 奥银焕[1] 李照国[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所寒旱区陆面过程与气候变化重点实验室,兰州730000 [2]中国科学院研究生院,北京100049

出　　处：《地理科学进展》2012年第11期1443-1451,共9页Progress in Geography

基　　金：国家自然科学基金项目(40975007);国家重点基础研究发展计划项目(2009CB421402;2010CB950503)

摘　　要：利用2009年7月24日-9月12日＂巴丹吉林沙漠陆—气相互作用观测试验＂资料,对比分析了典型晴天和阴天下巴丹吉林沙漠地表辐射、能量平衡和土壤温度的日变化规律。结果表明：①巴丹吉林沙漠典型晴天条件下总辐射、地表反射辐射、地表长波辐射、有效辐射、净辐射的峰值和日积分值都比典型阴天条件下大,大气长波辐射比阴天条件下小。两种天气条件下净辐射日积分值占太阳总辐射的1/3。②沙漠地区典型晴天地表反射率呈U型,白天均值为0.32;阴天变化较平缓,均值为0.29。③两种天气条件下地表热量平衡都以感热输送为主,波文比分别为4.55和1.16。晴天不平衡能量达到净辐射的20%,阴天为30%。④晴天条件下有效能量夜间为负值,白天为正值,阴天全天为正值;湍流能量全天均为正值。能量闭合度（EBR）晴天平均为0.68,阴天为0.76。⑤土壤温度5~10 cm日较差逐渐减小,20、40 cm日变化不明显;5 cm土壤热通量日变化较大,20 cm土壤热通量振幅较小。Based on the study of land-atmosphere interactions in Badain Jaran desert in the summer of 2009,this paper presents a comparative analysis of diurnal variations of surface radiation,energy budget and soil temperature under different synoptic conditions.As shown in the results：（1） In Badain Jaran desert,global radiation,surface reflection radiation,surface long-wave radiation,effective radiation and net radiation are all greater on typical clear days than those on typical cloudy days.However,atmospheric long-wave radiation is greater on cloudy days.Under both weather conditions,daily integral value of net radiation is 1/3 of global radiation.（2） The distribution of day-time surface albedo on clear days takes a U shape with an average value of 0.32,while it is relatively flat on cloudy days with an average value of 0.29.（3） The sensible heat transfer is the major component of the surface energy budget.On clear days and cloudy days,Bowen ratio（the ratio of sensible heat to latent heat） is 4.55 and 1.16 respectively,and imbalance energy accounts for 20% and 30% of net energy respectively.（4） The effective energy is negative in day time and positive in night time on clear days,and is positive all the time on cloudy days.Turbulent energy is always positive.The average EBR（energy budget ratio） is 0.68 on clear days and 0.76 on cloudy days.（5） The diurnal variations of soil temperature decrease as the depth changes from 5 to 10 cm（Δ15.7℃ vs.Δ9.4℃）.In 20~40 cm depth range,there is almost no diurnal variation.Under both weather conditions,soil heat flux shows greatest diurnal variations at 5 cm depth and very little at 20 cm depth.

关 键 词：巴丹吉林 沙漠 辐射 能量平衡 

分 类 号：P422.2[天文地球—大气科学及气象学]