佛山内部风场特征与能见度的相关性分析

Correlation Analysis between Internal Wind Field Characteristics and Visibility in Foshan

采用佛山市2000—2016年各区域自动站和南海、三水、顺德3个国家观测站资料,运用累积百分率、回归等统计方法,分析了佛山市各区能见度、近地层风,结果发现:(1)三站的能见度随着时间的推移呈持续上升的趋势,但是能见度低值与高值的差距越来越大,南海和顺德整体能见度呈持续上升的趋势,能见度高值和中值上升较明显,三水整体上升不明显;而三站的能见度低值上升的幅度不大,整体呈现比较平整的发展趋势。(2)夏季佛山风场以西风和西南风为主,其中在三水区域以西北风为主导。风速与南海和顺德的夏季能见度整体基本呈现负相关的状态,整体的西风和西南风风速越大,南海和顺德能见度越差;而在三水靠北的区域中出现相关系数为正的区域,意味着在三水区域的西北风与南海与顺德能见度有呈正的相关关系,当三水出现西北风异常加大时,南海和顺德的能见度为正异常。三水的能见度更多与当地的西北风相关关系有关。(3)三水和高明区域主要受到西北风的作用,南海主要受南风和北风交汇影响,而顺德主要受西南风的作用。南海和顺德能见度与市内的风速基本呈现负相关关系,其中负相关区域主要由北向南延伸,在影响南海和顺德的南北风交汇的风速减弱时,两站的能见度出现正异常。秋冬季节,在市内南风出现整体控制,或者北风整体控制时,能见度才会出现正异常。(4)两者交汇风速加快时,能见度就会出现负异常。三水的能见度与当地北风区域呈正相关关系,北风对三水当地污染物的清除作用较大。

Based on the data of automatic stations in each region and three national observation stations in Nanhai,Sanshui and Shunde from 2000 to 2016,the visibility and near-ground wind in each district of Foshan city were analyzed by statistical methods such as cumulative percentage and regression.The results showed that:(1)The visibility of the three stations showed a trend of continuous increase over time,but the gap between low and high visibility became larger and larger.The overall visibility of The South China Sea and Shunde showed a trend of continuous increase,and the high and median visibility increased significantly,while the overall visibility of Sanshui increased not significantly.However,the low visibility of the three stations showed a relatively smooth development trend.(2)The wind field in Foshan is dominated by west wind and southwest wind in summer,and northwest wind was dominant in Sanshui area.There was a negative correlation between wind speed and summer visibility in The South China Sea and Shunde.The greater the west wind speed and southwest wind speed,the worse the visibility in the South China Sea and Shunde.The positive correlation coefficient appears in the area to the north of Sanshui,which means that the northwest wind in Sanshui had a positive correlation with the visibility of the South China Sea and Shunde.When the northwest wind abnormally increases in Sanshui,the visibility of the South China Sea and Shunde is positive anomaly.The visibility of Sanshui wass more related to the local northwest wind.(3)Sanshui and Gaoming are mainly influenced by northwest wind,the South China Sea was mainly influenced by the convergence of south wind and north wind,and Shunde is mainly influenced by southwest wind.The visibility of The South China Sea and Shunde showed a negative correlation with the wind speed in the city,and the negative correlation area mainly extended from north to south.When the wind speed of the south-north wind intersection affecting the South China Sea and Shunde weakened,the visibility of the two stations showed a positive anomaly.In autumn and winter,visibility will be abnormal only when the overall control of the south wind or north wind occurs in the city.(4)When the wind speed speeds up,visibility will appear negative anomaly.The visibility of Sanshui is positively correlated with the local north wind area,and the north wind had a great effect on the removal of local pollutants in Sanshui.