Although the concentration of atmospheric particulate matter in Shanghai has declined in recent years,aerosols remain one of the major pollutants affecting air quality.Herein,spatio-seasonal variation in aerosol optic...Although the concentration of atmospheric particulate matter in Shanghai has declined in recent years,aerosols remain one of the major pollutants affecting air quality.Herein,spatio-seasonal variation in aerosol optical properties and aerosol types were studied overa 10-year period(2006-2015)in Shanghai,China,using satellite data from Moderate Resolution Imaging Spectroradiometer(MODIS)and CloudAerosol Lidar with Orthogonal Polarization(CALIOP).The average aerosol optical depth values for central urban and suburban areas of Shanghai were between 0.9 and 1.0.Clear seasonal variation in aerosol concentrations occurred,causing strongest attenuation in summer and weakest attenuation in autumn.Polluted dust,polluted continental(urban/industrial)and smoke aerosols were the main aerosol types.Desert dust aerosols occurred in the Shanghai area at higher altitudes(greater than 3 km)in spring,related to dusty weather in the north;while in winter,smoke aerosols occurred at high altitudes,related to haze pollution in the north.The aerosols detected in autumn were mainly from local sources,comprising polluted dust,polluted continental,and smoke aerosols.Aerosols in Shanghai clearly reflect both local and regional sources at different times.展开更多
This paper retrieves the yearly and monthly mean 0.75μm aerosol optical depth(AOD)of 41 A-class solar radiation stations over China from 1979 to 1990,and analyzes the spatial and temporal distribution of AOD over Chi...This paper retrieves the yearly and monthly mean 0.75μm aerosol optical depth(AOD)of 41 A-class solar radiation stations over China from 1979 to 1990,and analyzes the spatial and temporal distribution of AOD over China mainland.The data employed are daily direct solar radiation and sunshine duration,as well as the TOMS version-7 ozone observation data in the same time.The results indicate that the Siehuan Basin is the largest center of yearly mean AOD over China.and the other two larger centers lie in Wuhan City and the South Xinjiang Basin, separately.AOD values are also relatively larger in the middle-and-lower reaches area of Changjiang River.Shandong Peninsula and coastal area of Guangdong Province:while in Yunnan Province,coastal area of Fujian Province.most parts of Northwest and Northeast China,AOD values are relatively smaller.The distribution of AOD varies with different months.In most parts of China.the maximum of AOD occurs in spring season;but the minimum varies in different regions,From 1979 to 1990.in the Qinghai-Xizang Plateau,West Siehuan Basin,North Guizhou Province.most areas of the middle-and-lower reaches of Changjiang River,Shandong Peninsula and west part of South Xinjiang Basin.AOD shows an increasing trend.But in Northeast China, most part of Northwest China,Yunnan-Guizhou Plateau,western Guangxi Region and the coastal areas of East China,AOD shows decreasing tendency.Generally,the seasonal variation characteristics of AOD in China can be classified into four typical models,i.e.,mono-modal types A and B,bimodal and Poly-modal.展开更多
基于MODIS 3 km AOD遥感数据,利用空间自相关模型及地理探测器对2010—2016年京津冀地区AOD的时空变化特征及其影响因子进行探测。结果表明:(1)2010—2016年京津冀地区年平均AOD值为0.83,其中天津市年均AOD值为研究区最高,河北省次之,...基于MODIS 3 km AOD遥感数据,利用空间自相关模型及地理探测器对2010—2016年京津冀地区AOD的时空变化特征及其影响因子进行探测。结果表明:(1)2010—2016年京津冀地区年平均AOD值为0.83,其中天津市年均AOD值为研究区最高,河北省次之,北京市最低。研究区及各分区AOD的7 a变化趋势大体一致,呈现先下降后上升再小幅波动的状态。(2)空间自相关分析表明京津冀地区AOD空间分布呈现显著正相关。局部高高聚集区主要集中在北京市东南部、天津市南部及河北省的中南部,低低聚集区集中分布在西北部山区。研究区高低聚集区面积均呈减小趋势,不显著区呈扩大态势。(3)地理探测器结果表明不同区域的主导影响因子不同,北京市首要影响因子为NDVI,其次为人口密度,且二者交互作用明显。天津市主导因子为风速,人口密度、第二产业生产总值等人为因子的作用力也较大,风速与其交互作用较强。河北省主导因子为人口密度,GDP与第二产业生产总值等的作用力次之,整体交互作用偏弱。通过地理探测器解析京津冀地区AOD空间分异的影响机理,其结果对我国大气污染治理具有重要意义。展开更多
This paper analyzes the correlation between variations of total and low cloud amounts and the varying features of aerosols related to urban development of Beijing by using the cubic spline fitting method based on the ...This paper analyzes the correlation between variations of total and low cloud amounts and the varying features of aerosols related to urban development of Beijing by using the cubic spline fitting method based on the monthly meteorological data of temperature,humidity,precipitation,clouds,and aerosol optical depth （AOD） during 1950-2005.The statistics on the development of the city of Beijing in this period,including the total industrial output,population,residential housing development,highway construction,charcoal production,etc.,is revealed.Accompanying the rapid urban development of Beijing over the past 55 years or so,the urban aerosol concentration and composition have changed.The results indicate that：1） there is a general trend of climate warming and drying in Beijing;2） the total cloud amount in all seasons declines drastically,but lower cloud amount climbs up slightly;3） the high correlations between cloud amount and the indices of Beijing urban development such as the housing area,charcoal production,and road construction show that the variation of cloud amount is closely related to the urban development;4） the changing trend of AOD coincides more closely with the variation of low cloud amount.The evident drop of total cloud amount is in agreement with the trend of climate warming and drying,while the slight growth of low cloud amount is likely caused by more haze and fog occurrences in the lower troposphere in association with the pollution responsible for the＂darkening＂of Beijing and the surrounding areas.展开更多
基金The MODIS and CALIOP data were obtained from NASA's Level-1 and Atmosphere Archive&Distribution System Distributed Active Center(LAADS DAAC)and Atmospheric Science Data Center(ASDC),respectively.This work was supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.91644211)the Fundamental Research Funds for the Central Universities(Grant No.2232019D3-27)+1 种基金the China Postdoctoral Science Foundation(Grant No.2019M651322)and the National Natural Science Foundation of China(Grant Nos.41905131 and 91637101).
文摘Although the concentration of atmospheric particulate matter in Shanghai has declined in recent years,aerosols remain one of the major pollutants affecting air quality.Herein,spatio-seasonal variation in aerosol optical properties and aerosol types were studied overa 10-year period(2006-2015)in Shanghai,China,using satellite data from Moderate Resolution Imaging Spectroradiometer(MODIS)and CloudAerosol Lidar with Orthogonal Polarization(CALIOP).The average aerosol optical depth values for central urban and suburban areas of Shanghai were between 0.9 and 1.0.Clear seasonal variation in aerosol concentrations occurred,causing strongest attenuation in summer and weakest attenuation in autumn.Polluted dust,polluted continental(urban/industrial)and smoke aerosols were the main aerosol types.Desert dust aerosols occurred in the Shanghai area at higher altitudes(greater than 3 km)in spring,related to dusty weather in the north;while in winter,smoke aerosols occurred at high altitudes,related to haze pollution in the north.The aerosols detected in autumn were mainly from local sources,comprising polluted dust,polluted continental,and smoke aerosols.Aerosols in Shanghai clearly reflect both local and regional sources at different times.
文摘This paper retrieves the yearly and monthly mean 0.75μm aerosol optical depth(AOD)of 41 A-class solar radiation stations over China from 1979 to 1990,and analyzes the spatial and temporal distribution of AOD over China mainland.The data employed are daily direct solar radiation and sunshine duration,as well as the TOMS version-7 ozone observation data in the same time.The results indicate that the Siehuan Basin is the largest center of yearly mean AOD over China.and the other two larger centers lie in Wuhan City and the South Xinjiang Basin, separately.AOD values are also relatively larger in the middle-and-lower reaches area of Changjiang River.Shandong Peninsula and coastal area of Guangdong Province:while in Yunnan Province,coastal area of Fujian Province.most parts of Northwest and Northeast China,AOD values are relatively smaller.The distribution of AOD varies with different months.In most parts of China.the maximum of AOD occurs in spring season;but the minimum varies in different regions,From 1979 to 1990.in the Qinghai-Xizang Plateau,West Siehuan Basin,North Guizhou Province.most areas of the middle-and-lower reaches of Changjiang River,Shandong Peninsula and west part of South Xinjiang Basin.AOD shows an increasing trend.But in Northeast China, most part of Northwest China,Yunnan-Guizhou Plateau,western Guangxi Region and the coastal areas of East China,AOD shows decreasing tendency.Generally,the seasonal variation characteristics of AOD in China can be classified into four typical models,i.e.,mono-modal types A and B,bimodal and Poly-modal.
文摘基于MODIS 3 km AOD遥感数据,利用空间自相关模型及地理探测器对2010—2016年京津冀地区AOD的时空变化特征及其影响因子进行探测。结果表明:(1)2010—2016年京津冀地区年平均AOD值为0.83,其中天津市年均AOD值为研究区最高,河北省次之,北京市最低。研究区及各分区AOD的7 a变化趋势大体一致,呈现先下降后上升再小幅波动的状态。(2)空间自相关分析表明京津冀地区AOD空间分布呈现显著正相关。局部高高聚集区主要集中在北京市东南部、天津市南部及河北省的中南部,低低聚集区集中分布在西北部山区。研究区高低聚集区面积均呈减小趋势,不显著区呈扩大态势。(3)地理探测器结果表明不同区域的主导影响因子不同,北京市首要影响因子为NDVI,其次为人口密度,且二者交互作用明显。天津市主导因子为风速,人口密度、第二产业生产总值等人为因子的作用力也较大,风速与其交互作用较强。河北省主导因子为人口密度,GDP与第二产业生产总值等的作用力次之,整体交互作用偏弱。通过地理探测器解析京津冀地区AOD空间分异的影响机理,其结果对我国大气污染治理具有重要意义。
基金Supported by the Special Grant in Atmospheric Sciences of the China Meteorological Administration(GYHY200706036)the National"973"Program of China(2011CB403404)the International Cooperation Project on Monsoon Monitoring (200 9DFA21430)
文摘This paper analyzes the correlation between variations of total and low cloud amounts and the varying features of aerosols related to urban development of Beijing by using the cubic spline fitting method based on the monthly meteorological data of temperature,humidity,precipitation,clouds,and aerosol optical depth （AOD） during 1950-2005.The statistics on the development of the city of Beijing in this period,including the total industrial output,population,residential housing development,highway construction,charcoal production,etc.,is revealed.Accompanying the rapid urban development of Beijing over the past 55 years or so,the urban aerosol concentration and composition have changed.The results indicate that：1） there is a general trend of climate warming and drying in Beijing;2） the total cloud amount in all seasons declines drastically,but lower cloud amount climbs up slightly;3） the high correlations between cloud amount and the indices of Beijing urban development such as the housing area,charcoal production,and road construction show that the variation of cloud amount is closely related to the urban development;4） the changing trend of AOD coincides more closely with the variation of low cloud amount.The evident drop of total cloud amount is in agreement with the trend of climate warming and drying,while the slight growth of low cloud amount is likely caused by more haze and fog occurrences in the lower troposphere in association with the pollution responsible for the＂darkening＂of Beijing and the surrounding areas.
