2006年5月27日~6月30日HEST2006大气科学实验对珠峰北坡山谷的辐射(总辐射、净辐射)和温、湿度、风等进行了综合观测。沿珠峰北坡山谷布设了3个观测站,3个测站的辐射、温度、风都表现出明显的日变化规律,它们在08:00或09:00(地方时,下同)达到极大值。3个测站总辐射和净辐射的日变化都比较一致。从日变化最大值出现的时间来看,各站的辐射通量早于气温,气温早于风速。3个测站中任意2站之间辐射(总辐射、净辐射)最大值之比与温度和风速最大值之比均比较接近。因辐射状况、地形结构、大气温度等不同,远离珠峰区域的风一天之内多次改变风向,靠近珠峰区域则24h都为南风。珠峰北坡山谷不同区域风向风速变化存在明显时差,南风强于北风,且持续时间长。研究表明,辐射能量对于珠峰北坡大气运动具有重要的驱动作用,是控制和改变其大气运动方式最基本、最重要的因子。净辐射在不同区域风向转变或风速变化过程中起着决定性的作用。
Solar global radiation, net radiation, temperature, humidity, and wind were measured on the north slope of the Mount Qomolangma from May 27 to June 30, 2006. 3 stations were set up alone with the north slop of the Qomolangma, the measured radiation, temperature, wind showed an evident diurnal variation at 3 stations, and reached their daily maximums of changing rates at 08:00, 09:00, respectively. Solar global and net radiation displayed similar diurnal pattern. For the beginning time of daily maximum, radiation is earlier than temperature, and temperature earlier than wind speed for all stations. The ratio of daily maximum of radiation including global and net radiation and the ratio of daily maximum of temperature and wind speed for any 2 stations were closer. For monthly averaged diurnal variation, wind direction in the region far away from the Qomolangma was changed several times during a day, but wind direction in the region near the Qomolangma wasn't changed, and was south wind all the time, which was caused by the difference of radiation, geological structure, air temperature, and etc. The change of wind (including direction and speed) alone valley on the north slop of the Qomolangma exhibited an obvious time lag, and south wind was stronger the north wind, and persisted longer time. Radiative energy plays an important driving role on the motion of the atmosphere on the north slop of the Qomolangma, and is the most basic and important factor to control and change the motion manner of the atmosphere. Net radiation plays a critical role in the processes of the changing of wind direction and speed at different regions.