摘要
SO2 is an important gas in atmosphere with great environmental and climate implications.SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in the past few decades.SO2 has been observed from July 2005 to June 2010 at Linan WMO GAW regional station(30.3 °N,119.73 °E,138 m a.s.l.) located in the Yangtze Delta region in eastern China.These observation data are analyzed to understand the trend of regional SO2 background concentration.Strict quality controls are conducted to ensure the temporal comparability of the data.Significant downward trend with ?2.4 ppb/yr(P < 0.0001) of surface SO2 is observed from 2005 to 2010,especially after 2008.The average concentration of SO2 from July 2005 to June 2008 is 14.2±3.1 ppb,which is slightly higher than the mean values of 13.5±5.1 ppb during 1999?2000 and is two folds of the average value(7.1±3.1 ppb) from July 2008 to June 2010.More than 50% of the SO2 has been cut down after 2008 in the Yangtze Delta region due to the implementation of stricter emission control measures.The peak SO2 concentration appears around 10 o'clock in the morning after 2009 while appears at night before 2009.These diurnal variations of SO2 might indicate that after 2009,more SO2 is from the vertical exchange process than from the local accumulation.
SO2 is an important gas in atmosphere with great environmental and climate implications. SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in the past few decades. SO2 has been observed from July 2005 to June 2010 at Linan WMO GAW regional station （30.3 °N, 119.73 °E, 138 m a.s.l.） located in the Yangtze Delta region in eastern China. These observation data are analyzed to understand the trend of regional SO2 background concentration. Strict quality controls are conducted to ensure the temporal comparability of the data. Significant downward trend with -2.4 ppb/yr （P 〈 0.0001） of surface SO2 is observed from 2005 to 2010, especially after 2008. The average concentration of SO2 from July 2005 to June 2008 is 14.2±3.1 ppb, which is slightly higher than the mean values of 13.5±5.1 ppb during 1999-2000 and is two folds of the average value （7.1±3.1 ppb） from July 2008 to June 2010. More than 50% of the SO2has been cut down after 2008 in the Yangtze Delta region due to the implementation of stricter emission control measures. The peak SO2 concentration appears around 10 o＇clock in the morning after 2009 while appears at night before 2009. These diurnal variations of SO2 might indicate that after 2009, more SO2 is from the vertical exchange process than from the local accumulation.
基金
supported by the Planning Project Fund of Humanities and Social Science,Ministry of Education,China (11YJAZH071)
the Basic Research Fund of CAMS (2011Z003)
CMA (GYHY200706036)
Desert Meteorological Foundation of CMA (Sqj2010012)
