摘要
利用“我国西北干旱区陆 气相互作用试验”加强期 (IOP)在甘肃省敦煌绿洲观测的资料 ,系统地分析了夏季典型晴天敦煌地表辐射收支和地表能量平衡特征及小气候特征 ,结果发现 :敦煌绿洲总辐射特别大 ,其峰值高达10 38.1w·m-2 ;地表净辐射也高于其它地区 ,白天能超过 6 0 0w·m-2 ;在地表能量分配中 ,感热、潜热和地热流量的日积分值的量级相当 ,白天地热流量比潜热要大 ,几乎与感热相当 ;地表反照率除中午比较接近荒漠戈壁的值外 ,其它时候均明显比荒漠戈壁的值小 ;Bowen比在白天 1～ 2之间 ,比一般灌溉地区要大。地表能量不平衡差额较大 ,这可能与水平热通量的影响有很大关系。另外 ,还首次发现了比较可观的下沉气流 ,部分证实了绿洲与荒漠之间存在的热力环流。
Utilizing the data of the intensive observation period (May-June 2000) in Dunhuang oasis of Dunhuang land-surface process field experiment that belongs to 'Land-atmosphere Interactive Field Experiment over Arid Region of Northwest China', the radiation budget, energy balance and microclimate at surface in Dunhuang oasis are analyzed systemically. It is found that, (a) the short-wave irradiance at surface in Dunhuang oasis is very high and can reach 1 038.1 w·m -2, (b) the surface net radiation can exceed 600 w·m -2, (c) the daily-integral values of sensible heat flux, latent heat flux and soil heat flux are in same order of magnitude, and (d) soil heat flux is larger than latent heat flux and is almost in same order of magnitude, in the partition of surface energy. The daily-integrated values of the short-wave irradiance, downward long-wave, upward long-wave and reflection radiation over Dunhuang oasis are 31.17, -36.15, 27.51 and -8.08 MJ·m -2·d -1, respectively. The daily integration of the net radiation is 14.53 MJ·m -2·d -1, and accounts for about 50% of that of the short-wave irradiance. The daily-integrated values of the sensible heat, the latent heat and the soil heat flux over Dunhuang oasis are respectively 4.04, 4.31 and 2.02 MJ·m -2·d -1 which account respectively for 27.7 %, 30.00% and 14.0 % of the net radiation. The residue of energy budget arrives at 28.7%. The surface albedo of oasis is always evidently bigger than that of Gobi desert except for noon when the surface albedo of oasis is evidently bigger than that of Gobi desert. The Bowen ratio over oasis is within 1-2, which is larger than that over desert (or Gobi). The considerable deficit of surface energy budget found in Dunhuang oasis, maybe the result of local thermodynamic circulation caused by surface thermodynamic difference between oasis and desert nearby.
出处
《植物生态学报》
CAS
CSCD
北大核心
2002年第6期717-723,共7页
Chinese Journal of Plant Ecology
基金
国家自然科学基金项目 (4 0 175 0 0 4)
国家重点基础研究发展规划项目 (G19980 40 90 6_2 )
中国科学院知识创新领域前沿项目(2 2 0 0 0 5 )资助
