Air mass factor calculations for GOME measurements of lightning-produced NO 2

Abstract

The quantification of lightning-produced nitrogen oxide is difficult as the NO x-measurement must be concurrent with the thunderstorm. Also the interpretation of the measurements is complicated by the inhomogeneity of the clouds. Currently, the global NO x-production by lightning is estimated to be 2–20 TgN/a. This study analyses the possibility of the detection of NO 2-production by thunderstorms via satellite. Lightning can be detected by NASA/NASDA-satellite project Lightning Imaging Sensor (LIS). The European satellite spectrometer Global Ozone Monitoring Experiment (GOME) can be used for the coincident NO 2-measurements. For a quantitative analysis of NO 2 measurements, the air mass factor (AMF) is needed. AMF are calculated using the radiative transfer model SCIATRAN and indicate the sensitivity of GOME for NO 2 produced by flashes. The results of the AMF calculations show, that the sensitivity of GOME is largest at the top of a thundercloud, where most of the flash produced NO x is released. The measurement is insensitive to NO 2 under the thundercloud. For a quantitative analysis, the height of the cloud is needed, but the dependencies of the sensitivity to the height of the NO 2 outside the cloud and the cloud particles density are negligible.