Ozone Concentrations in Rural Regions of the Yangtze Delta in China
Ozone Concentrations in Rural Regions of the Yangtze Delta in China
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DOI：
10.1007/s10874-006-9024-z
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发表时间：
2006-07
影响因子：
2
通讯作者：
W. Huixiang;Z. Lijun;Tang Xiaoyan
中科院分区：
文献类型：
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作者：
W. Huixiang;Z. Lijun;Tang Xiaoyan
在1999年和2000年进行的为期16个月的实地试验期间，在中国长江三角洲的六个非城市地面监测点观测到臭氧浓度升高，这是中美中国-MAP联合项目（中国长江三角洲作为一个不断发展的大都市农业）的一部分。在监测期间，各地点的平均日间（0900-1600小时）臭氧水平为35至47 ppbv（按体积计算的十亿分之一），平均臭氧水平为26至35 ppbv。观测资料显示，臭氧的季节变化明显，5月份的混合比最高。5月，各地点白天的平均臭氧水平在60至79 ppbv之间。高臭氧浓度在春末最为普遍。臭氧小时平均浓度超过60 ppbv和40 ppbv的频数在5月份出现峰值，分别为22-39%和42-74%。在两次区域性事件中，观测到白天臭氧水平甚至更高，2000年5月10日和5月23日（0900-1600 h）臭氧浓度为68 - 81 ppbv，1999年10月18日和10月28日（59 - 67 ppbv）臭氧混合比的峰值出现在春末，而不是夏季，是夏季季风造成的。后向轨迹表明，臭氧事件与气象条件有关。此外，许多高臭氧水平与高CO水平和高CO与NOx的比率有关，这表明涉及不完全燃烧的排放源的贡献。
Elevated concentrations of ozone have been observed at six non-urban, surface monitoring sites in the Yangtze Delta of China during a 16-month field experiment carried out in 1999 and 2000 as part of the joint Chinese-American China-MAP Project (the Yangtze Delta of china as an Evolving Metro-Agro-Plex). The average daytime (0900–1600 h) ozone levels for the monitoring period at sites ranged from 35 to 47 ppbv (parts per billion by volume) and the mean ozone levels from 26 to 35 ppbv. Observed data show seasonal variation obviously, with highest mixing ratios of ozone in May. Average daytime ozone levels in May at sites were between 60 and 79 ppbv. High ozone concentrations were most prevalent during the late spring. Frequency counts of hourly mean ozone concentration over 60 ppbv and 40 ppbv appeared peak values of 22–39% and 42–74% in May at sites. Even higher daytime ozone levels were observed during two regional episodes, in which average daytime (0900–1600 h) ozone concentrations during 10 May and 23 May 2000 were 68 to 81 ppbv, during Oct. 18 and Oct. 28, 1999 were 59 to 67 ppbv at sites.Peak value of ozone mixing ratio appearing in late spring, instead of in summer, was attributed to summer monsoon. Backward trajectories showed that ozone episodes associated with meteorological conditions. Also many high ozone levels associated with high CO levels and high CO to NOxratios, which suggests a contribution from sources of emission involving incomplete combustion.