深圳两次雷暴过程中地面氮氧化物浓度变化特征分析

综合利用深圳云地闪探测数据和大气成分探测数据,对两次雷暴过程中氮氧化物(NOx)浓度升高的案例进行了分析。结果表明:1云地闪可明显影响地面NOx的浓度,电场强度增加伴随着NOx浓度的升高;2NO和NO2浓度升高的过程具有不同的特征,NO2浓度升高过程比较缓慢,高浓度值持续时间较长;但浓度峰值较低;NO浓度升高通常滞后于NO2浓度的升高,但其升高过程非常迅速,浓度峰值也高于NO2;同时其浓度从峰值下降到较低浓度水平也比较迅速;3地面风场结构、云地闪落区位置对NOx浓度观测响应时间的长短以及浓度峰值大小都有关系,因此分析云地闪与NOx浓度的变化关系,必须考虑背景气象条件。

Studies on characteristics of surface nitric oxides concentration variation during two cloud ground lightning cases in Shenzhen

By use of the lightning detection and nitric oxides concentration data during two cloud ground lightning cases in Shenzhen, the relationship between the electric field intensity and frequency of lightning and NOx concentration variation is analyzed. The results suggest that: (1) Along with the increase of electric field intensity, the concentration of surface NOx increased significantly. (2) There were different characteristics in the concentration increase procedures of NO2 and NO. Evidences showed that the process of NO2 was relatively slow but it kept for a longer period at the stage of high concentration. For NO, the response of its concentration to the lightning was slower than that of NO2, but the variation process of the concentration was much faster and the peak value of the concentration was higher than that of NO2. (3) The ground wind field and the location of the flashes had significant impact on the response time and the peak concentration of NOx.