SO 2 measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO 2 at different types of sites in Northern China.The overall average c...SO 2 measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO 2 at different types of sites in Northern China.The overall average concentrations of SO 2 are （16.8±13.1） ppb,（14.8±9.4） ppb,and （7.5±4.0） ppb at China Meteorological Administration （CMA,Beijing urban area）,Gucheng （GCH,relatively polluted rural area,110 km to the southwest of Beijing urban area）,and Shangdianzi （SDZ,clean background area,100 km to the northeast of Beijing urban area）,respectively.The SO 2 levels in winter （heating season） are 4–6 folds higher than those in summer.There are highly significant correlations among the daily means of SO 2 at different sites,indicating regional characteristics of SO 2 pollution.Diurnal patterns of surface SO 2 at all sites have a common feature with a daytime peak,which is probably caused by the downward mixing and/or the advection transport of SO 2 -richer air over the North China Plain.The concentrations of SO 2 at CMA and GCH show highly significant downward trends （–4.4 ppb/yr for CMA and –2.4 ppb/yr for GCH）,while a less significant trend （–0.3 ppb/yr） is identified in the data from SDZ,reflecting the character of SDZ as a regional atmospheric background site in North China.The SO 2 concentrations of all three sites show a significant decrease from period before to after the control measures for the 2008 Olympic Games,suggesting that the SO 2 pollution control has long-term effectiveness and benefits.In the post-Olympics period,the mean concentrations of SO 2 at CMA,GCH,and SDZ are （14.3±11.0） ppb,（12.1±7.7） ppb,and （7.5±4.0） ppb,respectively,with reductions of 26%,36%,and 13%,respectively,compared to the levels before.Detailed analysis shows that the differences of temperature,relative humidity,wind speed,and wind direction were not the dominant factors for the significant differences of SO 2 between the pre-Olympics and post-Olympics periods.By extracting the data being more representative of local or regional characteristics,a reduction of up to 40% for SO 2 in polluted areas and a reduction of 20% for regional SO 2 are obtained for the effect of control measures implemented for the Olympic Games.展开更多
Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan （WLG）, the only global ...Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan （WLG）, the only global baseline station in the back-land of the Eurasian Continent. The concentrations of SO2 and HNO3 were observed at WLG from 1997 to 2009. The observed annual mean concentrations of SO2 and HNO3 at WLG were 1.28 ± 0.41 and 0.22 ± 0.19 μg/m3, respectively. The HNO3 concentrations were much higher in warmer seasons than in colder seasons, while the SO2 concentrations showed a nearly reversed seasonal pattern. In most months, the concentration of HNO3 was significantly correlated with that of SO2, suggesting that some common factors influence the variations of both gases and the precursors of HNO3 may partially be from the SO2-emitting sources. The SO2 concentration had a very significant （P 〈 0.0001） decreasing trend （-0.2 μg/（m3.yr）） in 1997-2002, but a significant （P 〈 0.05） increasing trend （＋0.06 μg/（m3-yr）） in 2003-2009. The HNO3 concentration showed no statistically significant trend during 1997-2009. While the decrease of SO2 in 1997-2002 agrees with the trend of global SO2 emissions, the increase in 2003-2009 is not consistent with the decreasing trends in many other regions over the world. Trajectory analysis suggests that the airmasses from the northern Qinghai-Tibetan Plateau and the Takla Makan Desert regions contributed significantly to the increasing trends of SO2 and HNO3 at WLG in 2003-2009, with a rate of ＋0.13 μg/（m3.yr） and ＋0.007μg/（m3.yr）, respectively.展开更多
Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions...Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions to SO2 concentration and sulfur deposition at various sites in Japan downwind were analyzed. The results showed that from 2001 to 2009 annual average concentration of SO2 was 0 -150 μg/m^3 and showed a decreasing trend on the whole in China. The correlation coefficient of annual average concentration of SO2 at different sites in Japan and China＇s SO2 emissions was lower than that of annual average concentration and emission of SO2 in China＇s cities on the whole, showing that SO2 discharged in China had small impact on SO2 concentration in Japan. The contribution rate of China＇s SO2 emissions to annual average concentration of SO2 at various sites in Japan in 2010 was 7.5% -44.0%, averaging 22.6% ; the annual average volume concentration of SO2 at different sites in Japan caused by China＇s SO2 emissions was 0 -0.5 × 10^-9. The contribution rate of China＇s SO2 emissions to sulfur deposition at various sites in Japan in 2010 varied from 8.0% to 41.0%, averaging 22.1%.展开更多
基金supported by the National Basic Research Program of China (No.2005CB4222002)the National Natural Science Foundation of China (No. 20407001,40775074)+1 种基金the Basic Research Fund of CAMS (No. 2008Z011,2011CX001,2011Z003)the China Meteorological Administration(No. GYHY200706036,GYHY201106050)
文摘SO 2 measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO 2 at different types of sites in Northern China.The overall average concentrations of SO 2 are （16.8±13.1） ppb,（14.8±9.4） ppb,and （7.5±4.0） ppb at China Meteorological Administration （CMA,Beijing urban area）,Gucheng （GCH,relatively polluted rural area,110 km to the southwest of Beijing urban area）,and Shangdianzi （SDZ,clean background area,100 km to the northeast of Beijing urban area）,respectively.The SO 2 levels in winter （heating season） are 4–6 folds higher than those in summer.There are highly significant correlations among the daily means of SO 2 at different sites,indicating regional characteristics of SO 2 pollution.Diurnal patterns of surface SO 2 at all sites have a common feature with a daytime peak,which is probably caused by the downward mixing and/or the advection transport of SO 2 -richer air over the North China Plain.The concentrations of SO 2 at CMA and GCH show highly significant downward trends （–4.4 ppb/yr for CMA and –2.4 ppb/yr for GCH）,while a less significant trend （–0.3 ppb/yr） is identified in the data from SDZ,reflecting the character of SDZ as a regional atmospheric background site in North China.The SO 2 concentrations of all three sites show a significant decrease from period before to after the control measures for the 2008 Olympic Games,suggesting that the SO 2 pollution control has long-term effectiveness and benefits.In the post-Olympics period,the mean concentrations of SO 2 at CMA,GCH,and SDZ are （14.3±11.0） ppb,（12.1±7.7） ppb,and （7.5±4.0） ppb,respectively,with reductions of 26%,36%,and 13%,respectively,compared to the levels before.Detailed analysis shows that the differences of temperature,relative humidity,wind speed,and wind direction were not the dominant factors for the significant differences of SO 2 between the pre-Olympics and post-Olympics periods.By extracting the data being more representative of local or regional characteristics,a reduction of up to 40% for SO 2 in polluted areas and a reduction of 20% for regional SO 2 are obtained for the effect of control measures implemented for the Olympic Games.
基金supported by the National Natural Science Foundation of China(No. 21177157)the Basic Research Fund of Chinese Academy of Meteorological Sciences (No. 2011CX001,2011Z003)+1 种基金China Meteorological Administration(No. GYHY201106023)the Desert Meteorological Foundation of China Meteorological Administration (No.Sqj2010012)
文摘Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan （WLG）, the only global baseline station in the back-land of the Eurasian Continent. The concentrations of SO2 and HNO3 were observed at WLG from 1997 to 2009. The observed annual mean concentrations of SO2 and HNO3 at WLG were 1.28 ± 0.41 and 0.22 ± 0.19 μg/m3, respectively. The HNO3 concentrations were much higher in warmer seasons than in colder seasons, while the SO2 concentrations showed a nearly reversed seasonal pattern. In most months, the concentration of HNO3 was significantly correlated with that of SO2, suggesting that some common factors influence the variations of both gases and the precursors of HNO3 may partially be from the SO2-emitting sources. The SO2 concentration had a very significant （P 〈 0.0001） decreasing trend （-0.2 μg/（m3.yr）） in 1997-2002, but a significant （P 〈 0.05） increasing trend （＋0.06 μg/（m3-yr）） in 2003-2009. The HNO3 concentration showed no statistically significant trend during 1997-2009. While the decrease of SO2 in 1997-2002 agrees with the trend of global SO2 emissions, the increase in 2003-2009 is not consistent with the decreasing trends in many other regions over the world. Trajectory analysis suggests that the airmasses from the northern Qinghai-Tibetan Plateau and the Takla Makan Desert regions contributed significantly to the increasing trends of SO2 and HNO3 at WLG in 2003-2009, with a rate of ＋0.13 μg/（m3.yr） and ＋0.007μg/（m3.yr）, respectively.
基金Supported by the National Natural Science Foundation of China(41373131)National Key Technology R&D Program(2014BAC23B03)Major Tender Project of Social Science Foundation of Human Province,China(14DA12)
文摘Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions to SO2 concentration and sulfur deposition at various sites in Japan downwind were analyzed. The results showed that from 2001 to 2009 annual average concentration of SO2 was 0 -150 μg/m^3 and showed a decreasing trend on the whole in China. The correlation coefficient of annual average concentration of SO2 at different sites in Japan and China＇s SO2 emissions was lower than that of annual average concentration and emission of SO2 in China＇s cities on the whole, showing that SO2 discharged in China had small impact on SO2 concentration in Japan. The contribution rate of China＇s SO2 emissions to annual average concentration of SO2 at various sites in Japan in 2010 was 7.5% -44.0%, averaging 22.6% ; the annual average volume concentration of SO2 at different sites in Japan caused by China＇s SO2 emissions was 0 -0.5 × 10^-9. The contribution rate of China＇s SO2 emissions to sulfur deposition at various sites in Japan in 2010 varied from 8.0% to 41.0%, averaging 22.1%.
