Lightning production of NOX and ozone

Reactive nitrogen species play an important role in the chemistry of both t he stratosphere and the troposphere. Lightning emission is one of the main sources of NOx in the troposphere. NOx, in turn, affects the concentration of ozone in the atmosphere, which is an important greenhouse gas. A two-dim ensional model of radiative, dynamical and photochemical processes in the s tratosphere has been developed and used in this study. The main goal of the study is to evaluate the influence of NOx lightning source strength on the distribution of ozone in the troposphere and low stratosphere. The lightni ng source intensity is prescribed as a function of latitude, altitude and s eason. Several numerical simulations with different. values of total lightn ing source of NOx have been carried out. Simulated by our 2-D model NOy and O-3 mixing ratios are compared with available aircraft observations. The c omparison shows that the model cannot be tuned on the basis of the aircraft data because of their large uncertainty. The results of the simulation rev ealed that the best choice of total lightning emission value can be made by comparison of the model with the TOMS total ozone measurements. (C) 1999 E lsevier Science Ltd. All rights reserved.