乌鲁木齐冬季浅薄型焚风对大气扩散条件及空气质量的影响  

The Influence of Shallow Foehn on Atmospheric Diffusion Conditions and Air Quality over Urumqi in Winter

作　　者：赵克明[1,2,3,4] 李霞 孙鸣婧[3] 于碧馨 阿不力米提江.阿布力克木 卢新玉 ZHAO Keming;LI Xia;SUN Mingjing;YU Bixin;Ablimitjan Ablikim;LU Xinyu(Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,China;Center for Central Asia Atmosphere Science Research,Urumqi 830002,China;Xinjiang Meteorological Bureau,Urumqi 830002,China;College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [2]中亚大气科学研究中心,新疆乌鲁木齐830002 [3]新疆气象台,新疆乌鲁木齐830002 [4]兰州大学大气科学学院,甘肃兰州730000

出　　处：《沙漠与绿洲气象》2019年第1期13-20,共8页Desert and Oasis Meteorology

基　　金：国家自然科学基金(41575011);中亚大气科学研究基金(CAAS201805);中央级公益性科研院所基本科研业务费专项资金项目(IDM201501)联合资助

摘　　要：基于2013—2015年冬季乌鲁木齐市6个环境监测站6类污染物逐时的浓度数据,结合乌鲁木齐逐时的地面气象数据、风廓线雷达及常规探空资料,分析了浅薄型焚风对大气扩散条件及污染物浓度变化规律的影响。研究发现:冬季乌鲁木齐浅薄型焚风的出现频率为57.3%,焚风气流平均气流底高约600 m,气流顶高约2100 m,气流厚度约1500 m;乌鲁木齐市冬季焚风日大气扩散条件与非焚风日相比,最大混合层厚度偏低200 m,逆温层厚度偏厚350 m,逆温差差异达4.4℃,逆温强度和平均风速差别不大;焚风日各污染等级的出现频率都高于非焚风日:Ⅲ-Ⅵ级污染日出现频率累积偏高18%,Ⅵ级严重污染日则必有焚风相伴随;除O3以外,焚风日里各类污染物浓度都高于非焚风日,但日变化规律类似;6类污染物浓度的空间分布在焚风日和非焚风日一致,但是各站污染物浓度均高于非焚风日(O3除外)。市区偏南地带空气质量稍优于市区中心和北部地区。Using hourly air pollutants concentration from six environmental monitor stations,meteorological data and wind profile radar data in winter during 2013-2015,the influences of shallow foehn on diffusion conditions and air pollution concentration over Urumqi were analyzed.The results showed that the occurrence frequency of shallow foehn was 57.3%in Urumqi in winter.The flow depth,base height and top height of shallow foehn were about 1500 m,600 m and 2100 m,respectively.The maximum mixing layer depth,the inversion depth,the temperature difference between the top and bottom of inversion layer on foehn days were 200 m lower,344 m thicker and 4.4℃ higher than the corresponding values on non-foehn days,respectively.However,the differences of wind speed and inversion intensity between on foehn days and on non-foehn days were slight.Also,the frequency of each pollution level on foehn days was higher than on non-foehn days with extra frequency of 18% from level Ⅲ to level Ⅳ.Moreover,there was foehn existence on days with air pollution level Ⅵ.Except for O3,the other five air pollutant concentrations at each environmental station on foehn days were all higher than those on non-foehn days but with similar diurnal variation.The spatial distributions of six air pollutants were almost same on foehn days and non-foehn days.Overall,the air quality at south urban area was relatively excellent than that at other areas.

关 键 词：浅薄型焚风 最大混合层厚度 逆温 日变化 空间分布 

分 类 号：P445[天文地球—大气科学及气象学] X16[环境科学与工程—环境科学]