摘要
利用NCEP/NCAR和FNL再分析资料以及NOAA扩展重建海温资料,结合2014年2月观测资料,探讨了2014年2月21-26日天津重污染天气过程的气象成因及预报分析。结果表明,重污染期间,东亚大槽和东亚冬季风呈现偏弱的态势,天津出现明显东南风异常且河北以南地区存在大范围高湿区,近地面层存在弱气流辐合且维持弱偏东或偏南风,对流层中低层为弱辐散下沉气流和西南气流,同时也存在逆温层结,这种静稳条件有利于黄渤海及河北以南的水汽和污染物平流输送至天津且在近地面聚集。HYSPLIT模式模拟显示污染物来源于河北省中南部,以平流和弱辐散沉降的方式输送至天津。湿度条件对于重污染天气的产生仅是必要条件,污染物大量聚集才是重要条件。WRF-CMAQ模式短期内能较好模拟重污染期间PM_(2.5)浓度空间分布及重污染天气结束时间;重污染同期及前期秋季阿留申群岛南部海域持续出现显著正海温距平,可以用作中长期预报的一个参考因素。
Based on NCEP/NCAR reanalysis data and NOAA extended reconstructed sea surface temperature data,combining observed data in February 2014,the meteorological causes of a heavy air pollution process（HAPP）occurred from February 21 to 26 2014 in Tianjin and its prediction approaches were discussed. Results show that during the HAPP,the East Asian trough and winter monsoon presented weaker than normal. There existed significant southeasterly anomalies and widespread high relative humidity（RH） areas in the south of Hebei Province and weak airflow convergence and partial easterly and southern in the surface layer. Weak divergence downward airflow and southwesterly occurred in the mid-low troposphere,and simultaneous inversion layer existed during the HAPP. The above stable situations were beneficial to the transportation of water vapor（WV） and enormous pollutants from Bohai,Yellow Sea and south-central Hebei Province to Tianjin and gathering in the surface layer. Simulated results of HYSPLIT model depicted that pollutants transported from south-central Hebei Province to Tianjin in the ways of advection and weak divergence deposition. RH is merely a necessary condition to the formation of HAPP,while the concentration of numerous pollutants is a key factor. WRF-CMAQ can better simulate spatial distribution of PM_（2.5）concentration and dispersing time of HAPP and it can be used as the tool for the shortrange forecast of HAPP. During HAPP,strong sea surface temperature anomalies（SSTA） occurred in the south waters of Aleutian Islands in February and previous autumn,which can be seemed as a factor for the Tianjin middle-long term forecast of HAPP.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2015年第12期77-82,157,共7页
Environmental Science & Technology
基金
天津市科技支撑项目(BZCZDSF02100)
天津市气象局科研专项(201407)
关键词
天津地区
重污染天气过程
气象条件
海温异常
成因分析
Tianjin area
heavy air pollution process（HAPP）
meteorological conditions
SSTA
cause analysis
