东亚地区闪电产生NO_X的时空分布特征

Spatial and Temporal Distributions of NO_X Produced by Lightning in East Asian Region

利用NASA提供的2.5°×2.5°卫星闪电格点资料(1995—2002年),并根据纬度区分云闪和地闪后,对东亚地区(75°～155°E,0°～55°N)闪电产生NOX的时空分布进行分析,结果表明:闪电产生的NOX在东亚地区的年总产量平均值为2.30Tg,自南向北存在7个极值中心,它们分别集中于南部、中部和北部极值群内,三个极值群的最大值分别为16.4,12.7和5.46Bg/grid/yr。与该地区NOX的非闪电排放源相比较,闪电产生NOX的分布范围大,年产量约为非闪电源年排放总量的23%。闪电产生NOX的量在夏季最大,其区域性特征很明显。地球表面特性的差异造成了闪电产生的NOX在经度分布上存在较大的不平衡性。在气候冷暖交替月份的中低纬度地区闪电产生NOX的增加对强雷暴活动年闪电产生NOX的贡献最为明显。

The spatial and temporal distributions of NO-X produced by lightning(LNO-X) in East Asia Region have been analyzed by using satellite-based lightning data of NASA. The results show that the average annual total production of LNO-X in East Asia is about 2.30 Tg. Seven peak value centers are found to be within the 3 peak value groups which are located in south, middle, and north. The maximum values for the three groups are 16.4, 12.7, and 5.46 Bg/grid/yr, respectively. Compared with the total NO(X) emissions excluded lightning, it is found that the LNO-X distributes in larger regions, although its annual production value is only 23% of total NO-X emissions excluded lightning. The production of LNO-Xin summer is the highest. The regional characteristics of LNO-Xare obvious. The numerous lightning activity in some geographical location with special topography characteristics in middle latitude area contributegreatly to the total NO(X) production, in particularly in the boundary area of India and south of Chinese Tibet. The difference of the ground surface features is one of the major reasons for the inhomogeneous distribution of LNO-X in longitude. The increase contribution of LNO-X in the months corresponding to the climatic transition between warm and cold season is remarkable. The monthly LNO-X is characterized by a year cycle with two peaks structure.