夏季晴空金塔绿洲温度场的初步分析

Preliminary Analysis on Temperature Fields of Jinta Oasis under Clear Sky in Summer

利用2004年6～8月在甘肃省酒泉金塔地区开展的“绿洲-沙漠能量和水分循环的野外观测试验（JTEX）”的温度场资料，分析了该地区的温度场结构。结果表明：绿洲在白天（夜晚）相比周围环境是冷（暖）中心。沙漠和绿洲的相互影响同沙漠与绿洲的边缘和形状有关。由于各观测点所处的位置和站点的土壤特性不同，地表温度的量值有较大差别，但总体来说，绿洲的地表温度比沙漠的低；土壤温度的垂直变化一直可活跃到大约20cm深处，40cm深土壤温度基本无日变化，不同层间的土壤温度在一天内有两次相交。深度越深，出现的时间越靠后，沙漠上出现不同深度间温度交叉的时间比绿洲靠后。沙漠上各层的温度都始终高于绿洲上的，沙漠的日变化也大于绿洲上的。

Characteristics of the temperature fields observed in the ＂JTEX＂ field test were analyzed. The results are showed as follows： The cold center and the warm center of oasis formed respectively in daytime and nighttime; The interaction between oasis and desert has relation with their edge and shape; There were obvious difference of ground temperature among the observation stations due to their different sites and soil types. Generally, the ground temperature of oasis was always lower than that of desert in daytime. In oasis, the vertical variation of soil temperature could be active till 20 cm below the surface, and there was no daily variation below 40 cm; The soil temperature of different layers were same twice in one day, the deeper the layer the later the same temperature appeared. For the same two layers, the temperature-being-same in oasis appeared earlier than that in desert. The soil temperature of every layer in desert was always higher than that in oasis, and the daily variation of different layers in desert was more obvious than that in oasis.