沙尘天气等对西安市空气污染影响的研究  

Influence of Dust Storms and Other Meteorological Factors on Air Pollution in Xi'an City

作　　者：王建鹏[1] 王式功[2] 孟小绒 赵燕宁[4] 林杨 刘小英 

机构地区：[1]南京气象学院,江苏南京210044 [2]兰州大学资源环境学院大气科学系,甘肃兰州730000 [3]西安市气象局,陕西西安710016 [4]青海省气象台,青海西宁810001

出　　处：《中国沙漠》2004年第5期558-564,共7页Journal of Desert Research

基　　金：国家重点基础研究发展规划项目(G2000048703);科技部社会公益类项目(中国西北地区沙尘暴监测预警系统)共同资助

摘　　要：通过对西安市1981—2000年TSP、SO2和NOx年平均浓度资料,1998—2000年周报和日报环境监测资料以及相应的地面、高空常规气象观测资料的统计分析,研究了该市空气污染的时间变化特点以及沙尘天气等几种气象条件对其浓度变化的影响。结果表明:(1)颗粒污染物(TSP和PM10)是西安市的首要污染物,其次是SO2。1981—2000年期间,TSP年平均浓度降低了75%,SO2年平均浓度降低了77%,NOx年平均浓度总体上变化不大;这三种污染物月平均浓度的年变化都呈单周期型,冬季1月份最高,夏季最低(TSP是7月份最低,SO2和NOx是8月份最低)。(2)2001年春季3～4月份沙尘天气的频繁发生,使西安市空气污染日出现全年的第二个多发期(23d·月-1),这有别于正常年份仅在冬季1月份出现一个浓度峰值的特点;强沙尘暴天气过程会使西安市PM10浓度在非常短的时间内提高3倍左右,造成严重的颗粒物污染。(3)西安市冬半年出现轻度污染以上级别的几率明显大于夏半年。影响西安市的地面天气系统可归纳为12类,当受不同天气系统控制时,其污染状况会有较大差异。(4)西安市一年四季都有逆温存在,100m平均逆温强度为0.90℃;全年以低层逆温出现日数最多,但冬季贴地逆温出现日数最多,厚度最厚,强度最大,是造成西安市冬季空气污染严重的最重要气象因素之一。(5)Temporal variation of air pollution and influence of dust storms and other meteorological factors on air pollution in Xi'an City have been investigated by using data of annual mean concentration of TSP, SO_(2) and NO_(x) from 1981 to 2000, data of weekly reports and daily reports of environmental monitoring from 1998 to 2000 as well as data of routine surface and upper air observation. The research results are as follows: The particulate pollutant such as TSP or PM_(10) is chief pollutant in Xi'an,next one is SO_(2). During 1981—2000, annual mean concentration of TSP and SO_(2 )presents a trend of fluctuating decrease. Within the 20 years mean concentration of TSP reduced by 75%, SO_(2) concentration decreased by 77%, but mean concentration of NO_(x) hardly changed. Annual variation of monthly mean concentration of the three kinds of pollutants showed a single cycle, that is, they were the highest in January of winter and were the lowest in summer. (2) Sand-dust weather happened frequently in March and April of spring. This made a second highest period(23 days per month) of polluted days in the whole year in Xi'an, and it is different from the characteristics that the heaviest pollution occurs in January of winter. A severe dust storm could cause a very heavy particulate pollution that PM_(10) concentration increased by three times in a moment. (3)The probability of air pollution days was higher in cold half a year than in warm half a year in Xi'an. When Xi'an City was controlled by the foreside of high pressure system or the foreside of cold front, a moderate or heavy pollution easily happened there. When Xi'an City was controlled by high pressure system or homogeneous pressure system, only light pollution might happen. (4) In Xi'an City thermal inversion might occur in four seasons of a year, but its frequency was the highest in winter. Annual mean intensity of inversion was 0.90 ℃·(100m)^(-1). A low-level inversion happened most frequently in the whole year, but in winter close-to-ground inversion happene

关 键 词：沙尘天气 空气污染 环境监测 气象观测 

分 类 号：P445.4[天文地球—大气科学及气象学] X513[环境科学与工程—环境工程]