摘要
利用2007—2017年乌鲁木齐市L波段探空雷达和地面常规观测数据,以Holzworth干绝热曲线原理,估算该地逐日最大边界层高度,并计算对应的边界层平均风速和通风量等数据。同时,应用2015—2017年空气污染指数(AQI),探讨空气质量与大气边界层参数的关系。结果表明:乌鲁木齐市日最大边界层年均高度为1415 m,总体上呈下降趋势,平均降幅为5. 9 m·a^(-1)。时间序列上,日最大边界层高度分布呈明显周期性。逐月数据呈"抛物线"状,1月平均高度最低(336 m),6月平均高度最高(2400 m)。冬季边界层平均风速最小,为2. 6 m·s^(-1),春季和夏季最大,均为5. 6 m·s^(-1)。一年中,1月平均通风量最小,为977. 0 m^2·s^(-1),5月平均通风量最大,为14835. 9 m^2·s^(-1),4—9月为平均通风量大值期,平均通风量为13282. 3 m^2·s^(-1)。大气污染物在风速弱、边界层高度低和通风量小条件下的累积,易造成中度以上污染。冬季,乌鲁木齐常处于蒙古高压后部或底部,为造成冬季污染严重的重要原因之一。
Based on L-band radar and conventional observation data in Urumqi city from 2007 to 2017,the maximum daily boundary layer height was estimated using the principle of Holzworth dry adiabatic curve,and the corresponding average wind speed and ventilation volume of the boundary layer were calculated.Meanwhile,the air pollution index (AQI) from 2015 to 2017 was used to discuss the relationship between air quality and atmospheric boundary layer parameters.The results show that the average annual height of the maximum daily boundary layer is 1415 m,and demonstrates a downward trend,with an average decline rate of 5.9 m · a^-1 .In time series,the daily maximum boundary layer height distribution shows obvious periodicity.The monthly data presents a "parabola",with the lowest average height in January (336 m) and the highest average height in June (2400 m).In winter,the average wind speed of the boundary layer is the smallest,with 2.6 m · s^-1 ,and the largest in spring and summer,with 5.6 m · s ^-1 .In a year,the average ventilation volume in January is the smallest,which is 977.0 m ^2 · s^-1 ,and the average ventilation volume in May is the largest,which is 14835.9 m ^2 · s^-1 .From April to September,the average ventilation volume is 13282.3 m ^2 · s -1 .The accumulation of atmospheric pollutants under the conditions of weak wind speed,low boundary layer height,and small ventilation volume is easy to cause moderate pollution.In winter,Urumqi is always located at the rear or bottom of Mongolia high pressure,which is one of the important causes for serious pollution in winter.
作者
贾健
杨佩琪
蒋慧敏
JIA Jian;YANG Pei-qi;JIANG Hui-ming(Urumqi Meteorological Service,Urumqi 830000,China)
出处
《气象与环境学报》
2019年第2期55-60,共6页
Journal of Meteorology and Environment
基金
乌鲁木齐市气象局面上基金项目(Wk201801)资助
关键词
干绝热
日最大边界层高度
平均风速
通风量
Dry adiabatic
Daily maximum boundary layer height
Average wind speed
Ventilation volume
