乌鲁木齐大气边界层结构的四季特征初探

利用乌鲁木齐市2011～2012年08时、20时L波段(1型)雷达探测的高空资料建立了乌鲁木齐大气边界层气象要素数据库,分析了乌鲁木齐边界层内气温、风向、风速和相对湿度的垂直分布及其时间变化特征。结果表明：边界层内温度廓线的日变化和季节变化比较显著,各月均有逆温出现,且08时较20时更易出现逆温,冬季08时逆温层厚度较厚且强度最大。边界层内夏、冬两季风速随高度变化波动较大,春、秋两季变化较小。近地层春、夏、秋三季08时盛行西南偏南风,冬季盛行偏东风和西南风；20时春季盛行东北风,夏秋盛行偏北风和西北风,冬季则盛行东风和东北偏东风。08时、20时风向均随高度的增加呈明显的向右偏转趋势,且日风向的变化具有明显的“山谷风”特点。08、20时的相对湿度冬季最大,夏季最小,且随高度增加,春、夏两季08、20时相对湿度的变化较大。

Analysis on Atmospheric Boundary Layer Structure and Its characteristics in Different Seasons in Urumqi City

Based on the L-band radar system data during 2011 to 2012, we built the atmospheric boundary layer structure database in Urumqi city. And atmospheric boundary layer conditions, such as vertical distribution and time variation characteristics of temperature, wind velocity, wind direction and humidity, were analyszed. The results show that there have a significant changes in daily and seasonal variation in profiles of temperature in atmospheric boundary layer. There have temperature inversion in each month, and the morning(8:00) have more temperature inversion than the evening(20:00), as well as have a thicker and the strongest temperature inversion in winter. The wind velocity have a higher volatile change with altitude change in summer and winter, and the smaller in spring and autumn. The prevailing wind directions in surface layer was SSW in spring, summer, and autumn, and E, SW in winter in the morning. As well as NE in spring, N and NW in summer, E and ENE in winter in the evening. The wind direction has a significant right trend with altitude change, as well as the significant characteristics of mountainvalley breeze. There has a highest humidity in winter, and smallest in summer, as well as a higher variation with altitude change in spring and summer.