绿洲与荒漠背景夏季近地层大气特征的对比分析  

Comparison of Atmospheric Characteristics of Near-Surface Layer between Oasis and Desert Background in Summer

作　　者：张强[1] 王胜[1] 

机构地区：[1]中国气象局兰州干旱气象研究所

出　　处：《冰川冻土》2005年第2期282-289,共8页Journal of Glaciology and Geocryology

基　　金：国家科技部"西部开发科技行动"重大项目(2004BA901A16);国家自然科学基金项目(40175004)资助

摘　　要：利用观测试验资料, 对比分析了夏季典型晴天敦煌绿洲与周围荒漠戈壁背景近地面层大气特征的差异. 结果表明: 绿洲具有降温、保湿、风屏等效应, 地表温度和近地面层大气温度明显要比周围荒漠的低, 近地面层大气湿度要明显比周围荒漠的大, 近地面层大气风速和摩擦速度要比周围荒漠的小, 近地面层感热通量比周围荒漠小1/5, 近地面层潜热通量比周围荒漠大 10 倍左右. 同时, 绿洲与周围荒漠相比有比较可观的下沟运动, 这会对绿洲的能量和水分输送有贡献. 绿洲的 Bowen比大约是周围荒漠戈壁的1/20, 相差一个量级, 这说明绿洲和周围荒漠的气候特征相差十分明显.By using the observed data, the differences of atmospheric characteristics of the near-surface layer between oasis and its surrounding Gobi are analyzed in this paper, and the microclimate features in oasis eco-system on the background of Gobi were discovered. As a result, it is revealed that oasis has the effects of decreasing temperature, keeping humidity and wind shielding. The temperature in ground surface and near-surface layer is obviously lower, the atmospheric humidity in near-surface layer is larger and the wind velocity and friction velocity in near-surface layer are smaller in the oasis, as compared with those in its surrounding Gobi. The sensible heat in oasis is only 20% of that in Gobi, and the latent heat in oasis is 10 times that in Gobi. At the same time, there is a considerable downward vertical motion over the oases, which contributes to the transportation of energy and vapor in oases. The Bowen ratio of oasis is about 1/20 that of Gobi, showing an obvious difference in climatic features between oasis and Gobi.

关 键 词：绿洲 荒漠戈壁背景 近地面层大气 小气候特征 Bowen比 

分 类 号：P404[天文地球—大气科学及气象学]