摘要: |
利用美国NCEP/NCAR风场再分析资料和云南高空、地面、高山风塔实测风资料,对云南地区的大气风场特征进行了分析。结果表明,云南对流层中低层大气风场常年盛行偏西气流,风向稳定,尤以西南风最多,冬-春-夏-秋四季风场变化特征明显。腾冲、思茅高空盛行风向以西风为主。云南除滇东北、滇东南和局地地形影响外,大部分地区近地面全年以盛行西南风为主。山区全年盛行风向以西南风为主。云南近地面年平均风速1.9m/s,北部大于南部,东部大于西部,冬春季风大,夏秋季风小,风速日变化特征显著。昆明地区大气边界层存在逆温现象,冬季突出,夏季微弱,秋冬春季频率高,夏季频率低。云南空气污染具有干湿季分布特点,1-5月为主要污染时段,冬春季节存在西南和东北两条污染传输通道。 |
关键词: 大气风场;西南风;季节变化;逆温;空气质量 |
DOI: |
投稿时间:2023-02-02修订日期:2023-02-27 |
基金项目: |
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Analysis of Wind Field Characteristics Affecting Air Quality in Yunnan |
XIE Ming-en,YAO Yu,PENG Qi-yang,DOU Xiao-dong,FAN Li-zhang,LIU Ping-ying |
(Yunnan Meteorological Service Center;Yunnan Climate Center;Yunnan Meteorological Disaster Prevention Technology Center) |
Abstract: |
Based on the NCEP/NCAR wind field reanalysis data from the United States and the measured wind data from radiosonde stations, ground weather stations and mountainous wind observation towers in Yunnan, the characteristics of the atmospheric wind field in Yunnan are analyzed. The results show that the wind field in the middle and lower troposphere of Yunnan is dominated by westerly air in ordinary year, and the wind direction is stable, especially the southwest wind, and the variation of upper wind fields in winter, spring, summer and autumn is obvious. The prevailing upper wind direction at Tengchong and Simao radiosonde station is mainly west wind. In addition to the influence of northeast and southeast Yunnan and local topography, southwest wind prevails in most areas near the surface throughout the year. The prevailing wind direction in mountainous areas is mainly southwest. The average annual wind speed near the surface in Yunnan is 1.9m/s, which is larger in the north than in the south, and larger in the east than in the west. The wind speed is large in winter and spring, and the wind speed is small in summer and autumn, and the diurnal variation of wind speed is significant. The atmospheric boundary layer temperature inversion phenomenon exists in Kunming area, which is prominent in winter, weak in summer, high frequency occurs in autumn, winter ,spring and low frequency occurs in summer.Air pollution in Yunnan is distributed in wet and dry seasons,the main pollution period is from January to May. In winter and spring, there are two pollution transport channels in southwest and northeast. |
Key words: atmospheric wind field;southwester;seasonal variation;thermal inversion layer;air quality |