HR: 08:00h
AN: AE21A-01    [Abstracts]
TI: Surface Observation of NO$_{x}$ Produced by Lightning in Qinghai-Tibetan Plateau of China
AU: * Qie, X
EM: qiex@ns.lzb.ac.cn
AF: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, w. 260 Donggang Road, Lanzhou, 730000 China
AU: Zhou, Y
EM: zhouyj@ns.lzb.ac.cn
AF: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, w. 260 Donggang Road, Lanzhou, 730000 China
AB: The global production of nitrogen oxides are important for understanding many aspects of global atmospheric chemistry and the overall nitrogen cycle of the earth. But the production of NO$_{x}$ by lighting represents the largest uncertainty in the global NO$_{x}$ budget with varying by over two orders of magnitude. The global annual lightning-produced NO$_{x}$ budget is difficult to be estimated accurately without better understanding of the regional production of NO$_{x}$ by lightning and its role in regional atmospheric chemistry because lightning production is non-homogeneous in space and time. Here we present the surface observation of lightning-produced NO$_{x}$ on Qinghai-Tibetan Plateau, where no obvious artificial NO$_{x}$ sources and electromagnetic disturbance. The NOx concentration, average electric field, and types of lightning flashes have been observed in two sites of the Tibetan Plateau, Datong (2600m asl) in northeastern Qinghai province and Naqu (4500m asl) in northern Tibetan, by using NO$_{x}$ analyzer, electric field mill, as well as fast antenna system. In the stable atmospheric stratification of fine day, the values of NO$_{x}$ concentration and average electric field did not show visible variation. During thunderstorms, the peaks on surface NO$_{x}$ concentration are good correlated to lightning flashes, but with a distinct time lag between the NO$_{x}$ peak and the corresponding lightning flash. A linear correlation has been found between the increase of NO$_{x}$ concentration and the number of lightning flashes. The average increase of NO$_{x}$ concentration per lightning flash is 6.01ppbv in Naqu, and 90.6ppbv in Datong. The productions of NO by one lightning flash in Naqu is estimated to be 1.34\times10$^{26}$ molecules, and while that in Datong is 1.23\times10$^{28}$ molecules. Acknowledgement: This work is supported by National Natural Science Foundation of China (40135010).
DE: 3324 Lightning
DE: 3304 Atmospheric electricity
DE: 3314 Convective processes
SC: Atmospheric and Space Electricity [AE]
MN: 2004 AGU Fall Meeting