沙漠与城市气溶胶散射系数变化比较

利用塔克拉玛干沙漠大气环境观测试验站和中国气象局乌鲁木齐沙漠气象研究所承担的乌鲁木齐大气成分观测站2010年1月1日至12月31日的单波段积分浊度计的观测资料，分析了沙漠（塔中）和城市（乌鲁木齐）两种不同下垫面地区的气溶胶散射系数的变化特征。（1）散射系数小时平均值：塔中地区变化范围在39.6～8 442.8 Mm^-1，平均值318.4 Mm^-1；乌鲁木齐变化范围在28.9～6 590.0 Mm^-1，平均值451.5 Mm^-1；乌鲁木齐小时平均值在1 000 Mm^-1以上的高值区间大于塔中地区。（2）散射系数日变化：塔中呈现单峰变化，其中最大值387.0 Mm^-1出现于凌晨02：00，最小值276.4 Mm^-1出现于午后的17：00；乌鲁木齐呈现三锋变化，3个峰值分别出现于09：00、14：00、22：00，与塔中地区存在明显差异。（3）散射系数月均值变化：塔中的月平均值最大是4月，为500.2 Mm^-1，最小是2月，为145.9 Mm^-1；乌鲁木齐月均值最大在2月，为1 086.3 Mm^-1，最小值在7月，为101.1 Mm^-1，两地区月均值变化整体呈现相反的现象。（4）散射系数季节变化：塔中地区春季>夏季>秋季>冬季；乌鲁木齐冬季>秋季>春季>夏季。

Comparison of Aerosol Scattering Coefficiens between Desert and City

The observation data of single-band integral nephelometer from January 1, 2010 to December 31, 2010 in Taklimakan Desert atmospheric observations and Experiment Station (Tazhong, referred to as desert) and atmospheric composition observatories station (Urumqi, referred to city) were used to analyze the change characteristics of aerosol scattering coefficients of these two different underlying surface areas. The results showed that: (1) The hourly average aerosol scattering coefficients range from 39.6 to 8 442.8 Mm^-1 in Tazhong, and the average value is 318.4 Mm^-1; the hourly average aerosol scattering coefficients range from 28.9 to 6 590.0 Mm^-1 in Urumqi, and the average value is 451.5 Mm^-1; the hours with the average value above 1000 Mm^-1 in Urumqi was much more than that in Tazhong. (2) The diurnal variation of aerosol scattering coefficients shows a single peak in Tazhong, and the maximum value is 387.0 Mm^-1 which appears at 02:00, the minimum value is 276.4 Mm^-1 which appears at 17:00. The diurnal variation of aerosol scattering coefficients presents three peaks in Urumqi, and the three peaks appear at 09:00, 14:00, and 22:00, respectively. There were significant differences for diurnal variation between Tazhong and Urumqi. (3) In Tazhong, the maximum value of monthly average aerosol scattering coefficients is 500.2 Mm^-1 which appears in April, the minimum value of 145.9 Mm^-1 is in February. In Urumqi, the maximum value of monthly average aerosol scattering coefficients is 1 086.3 Mm^-1 in February, the minimum value is 101.1 Mm^-1 in July. The monthly change in the two regions as a whole shows an opposite trend. (4) The seasonal average values in Tazhong are ranked in the sequence of spring>summer>autumn>winter, and the seasonal average values in Urumqi are ranked in the sequence of winter>autumn>spring>summer.