乌鲁木齐市低空大气逆温特征分析

Temperature inversion characteristics of low-air atmosphere of Urumqi City

为了分析乌鲁木齐低层大气逆温变化特征,通过利用乌鲁木齐市气象站2000-2004年的探空观测资料,从逐日探空原始记录中提取得到贴地逆温、脱地逆温的底部、顶部高度、温度,分析它们的变化情况。乌鲁木齐市低空大气温度层结全年以弱稳定为主,一年四季都存在逆温层。冬季是逆温特征最为显著的季节,强度最强,平均为1.06℃/100 m。冬季逆温发生频率最高,平均为89%,贴地逆温厚度最厚,平均为860 m,脱地逆温底高平均为534 m,顶高平均为1 187 m。由于蒙古反气旋的冷空气在准噶尔盆地堆积,使得乌鲁木齐冬季近地面大气稳定。

In order to analyze the change characteristics of low-air temperature inversion, the original daily sounding records in Urumqi Meteorological Station were used to get the ground temperature inversion, heights of bottom and peak of untouched temperature inversion, temperature and analyze their temperature changes from 2000 to 2004. The results show that there is an infirmly-steady low-air temperature inversion over Urumqi City all the year round. In winter, the temperature inversion characteristic is the most remarkable with the strongest intensity, the highest occurring frequency, and the thickest ground inversion. Their average intensity, occurring frequency and ground inversion thickness are 1.06 ℃/100 m, 89 percent and 860 m, respectively. The average temperature inversion intensity is stronger than that of Lanzhou, Guiyang, Changchun and Beijing city zone and the average ground temperature inversion is thicker than that of Lanzhou, Guiyang, Changchun and Jinan in winter. The heights of untouched inversion bottom and inversion peak are 534 m and 1 187 m respectively. Because of the cold air from Mongolian anticyclone accumulating in the Junggar Basin and 5 months steady snow accumulation, the ground layer atmosphere in Urumqi City is relatively steady in winter.