为了进一步认识闪电活动与对流层氮氧化物的关系及更准确地估算中国地区闪电产生的氮氧化物(LNO_x)总量,选取人口稀疏,工业生产水平较低的青藏高原地区作为研究区域,基于LIS(Lightning Imaging Sensor)和GOME-2(The Global Ozone Monitoring Experiment-2)卫星探测仪资料,分析了青藏高原中部区域2009年1月至2012年2月闪电与对流层NO_2垂直浓度(VCD)月均值资料的时空分布特性和相关性。在此基础上,结合Beirle et al.(2004)的LNO_x估算方法,估算了中国内陆地区的LNO_x产量。结果表明:青藏高原地区对流层NO_2与闪电与在年际趋势、空间分布及季节变化上保持很好的一致性,闪电密度与NO_2VCD的线性拟合相关系数为0.84,这表明青藏高原地区NO_x受人为源影响小,是研究LNO_x的理想区域。基于拟合结果,估算得到中国内陆地区LNO_x的年均产量为0.15(0.03~0.38)Tg(N) a~(-1)。这一结论进一步缩小了以往研究中中国地区LNO_x产量估算的不确定范围,有助于更清楚地认识闪电在中国气候变化中的重要作用。
英文摘要:
In order to better understand the relationship between lightning activities and nitrogen oxide (LNO_x) in the troposphere, and estimate the lightning-generated NO_x production in China more precisely, monthly means of lightning density and tropospheric NO_2 vertical column densities (VCD) from the Tibetan Plateau, where there is a sparse population and underdeveloped industrial activity, are analyzed in terms of their distribution and correlation. The data are obtained from LIS (Lightning Imaging Sensor) measurements and GOME-2 (the Global Ozone Monitoring Experiment-2) from January 2009 to February 2012. The LNO_x production in inland China is estimated based on Beirles LNO_x estimation method. The results show that the tropospheric NO_x over the selected region of inland China is influenced little by anthropogenic sources. Lightning densities over the region are in reasonable agreement with tropospheric NO_2 in terms of annual, spatial and seasonal variations. Combined with the correlation coefficient of 0.84 calculated by linear fitting, LNO_x production in inland China is evaluated as 0.15 (0.03-0.38) Tg(N) a~(-1). It is indicated that the Tibetan Plateau is an ideal area to study LNO_x. The conclusion further reduces the estimation uncertainty range of LNO_x production in previous work, helping us to more clearly recognize the important role of lightning in climate change in China.