Extreme urban haze is common in China and this pollution is transported over long range to the Pacific and the United States where it can damage human health and ecosystems. Therefore understanding the chemistry that produces this Chinese haze is important to us. Preliminary data and analysis show that current models grossly under-predict the fine particle pollution in this haze in China. This demonstrates that the chemistry in current models is incorrect and that we do not have confidence in their predictions that are used for assessments worldwide. The proposed work will measure the chemical and isotopic composition of the extreme haze in Beijing and analyze it with models to rectify this problem. The results should improve the forecasting of extreme air-pollution in China and also the exposure to the American population since this is transported over the Pacific to the United States.
The researchers will collect samples of fine particle pollution in the urban haze in Beijing. The samples will be brought to US where their mass, chemical composition (sulfate and nitrogen), and the oxygen isotopic composition of the fine particle pollution will be measured. The oxygen isotope data will then be used to fingerprint the chemical mechanisms that are amplifying the particle pollution in the haze. A US developed high-resolution chemistry, transport and isotope enable model centered over Beijing that will be adjusted to match the isotope observation. This revised model should be better constrained and more realistically capture the large particle-production measured in the Chinese haze and also its long-range transport to the United States.
