关键词: 地表辐射平衡, 地表能量平衡, 小气候, 绿洲荒漠过渡带, 张掖

Abstract:

Based on the data intensively observed on June 24 to July 26, 2006 in Zhangye Arid Meteorology and Ecological Environment Experimental Station, the surface radiation balance, energy balance and microclimate were analyzed systemically for the oasis-desert ecotone of Zhangye on these typical clear days in summer. It is showed that the solar radiation is high (can reach 1 000 W\5m-2) and the surface net radiation is also high, which indicates that the a vailable heat energy is so ample that the necessary condition is provided for heating the atmosphere and soil. During the courses of surface energy distribution, the most of energy is used for sensible heat exchange caused by atmospheric flow, the following is soil exchange, but the energy used for water evaporation is relatively low. The diurnal variation of air temperature in surface layer is contrary to that of humidity in oasis-desert ecotone. At daytime, the air temperature is increasing gradually with the increase of the height, and at night, the air temperature is decreasing gradually with the increase of the height. The diurnal variation of surface layer air temperature is far slower than that of surface temperature. At daytime, solar radiation can increase soil temperature, and the lower the soil layers is, the faster the soil temperature increases. At night, the soil temperature drops, especially in the soil layers near to the land surface，the drop of soil temperature is obvious. The horizontal wind speed of surface layer air is relatively large at daytime, and gradually decreases at night. The air vertical movement is downward in a whole day. Horizontal wind speed increase obviously with increasing height.

Key words: surface radiation balance, surface energy balance, microclimate, oasis-desert ecotone, Zhangye