中国东部地区SO2, SO4=和HNO3(g)干沉降速度的季节变化
THE SEASONAL VARIATION OF SO2, SO4= AND HNO3(g) DRY DEPOSITION VELOCITIES OVER EASTERN CHINA
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摘要: 使用中国东部及其邻近地区各主要台站1992年全年00点和12点(GMT)地面及探空资料,由中尺度气象预报模式MM4产生中国东部地区地面以上大约40m高度(最低模式层)处二维温度、湿度和风场,使用污染物干沉降模块及该地区下垫面类型资料,计算出了该地区SO2,SO4=和HNO3(g)全年干沉降速度的区域分布和季节变化。结果表明,由于受气象条件和下垫面类型的综合影响,3种污染物的干沉降速度有明显的变化。对SO2,全年区域平均极小值为0.088cm/s,极大值为1.275cm/s,平均值为0.430cm/s;对SO4=,分别为0.014cm/s,0.287cm/s和0.118cm/s;对HNO3(g),分别为0.060cm/s,5.250cm/s和1.123cm/s。SO2干沉降速度极大值分布在巴丹吉林沙漠和腾格里沙漠一带,对SO4=和HNO3(g),除在上述沙漠地带有一极大值区域外,在靠近四川的云贵高原尚有另一极大区。对1992年全年来说,SO2和HNO3(g)干沉降速度极大值均出现在七月份,分别为0.552cm/s和1.518cm/s;而对SO4=,干沉降速度极大值出现在九月份,其值为0.096cm/s。这些值均在实测范围内。Abstract: SO2, SO4= and HNO3(g) dry deposition velocities and their seasonal variations at a height of approximately 40m above sruface over eastern China were calculated using MM4 mesescale meteorological model by combining detailed landuse data with meteorological information throughout 1992. It was found that spatial and time variations of SO2, SO4= and HNO3(g) dry deposition velocities are very notable because of the combining influences of meteorological conditions and landuse. SO2, SO4= and HNO3 (g) domain-averaged dry deposition velocities vary among 0.088-1.275cm/s, 0.014-0.287cm/s and 0.060-5.250cm/s, respectively, the averaged values are 0.430cm/s, 0.118cm/s and 1.123cm/s, respectively. There was a maximun value region of domain-averaged SO2 deposition velocity in Badain Jarain Desert and Tengger Desert, but for SO4= and HNO3 (g), there was also an other maximum value region in northern part of Yun-Gui Plateau except above mentioned areas. For one year period, SO2 and HNO3(g) maximum domain-averaged dry deposition velocities appeared in July 1992, which was 0.552cm/s and 1.518cm/s, respectively, but for SO4=, that appeared in September, and was 0.096cm/s. These values were all in the field measurement scope.