Observational‐ and modeling‐based budget of lightning‐produced NOx in a continental thunderstorm

Abstract

NOx transport and production by lightning for the 10 July 1996 Stratosphere‐Troposphere Experiment‐Radiation, Aerosols, and Ozone convective storm is examined using radar, in situ observations and cloud model simulations. Observations and model simulations indicate that most of the NOx produced by the storm was transported out into the anvil. The analyzed NOx flux into the anvil, combined with results from a cloud model simulation, indicate that approximately 60 percent of the NOx transported into the anvil during the observational period is produced by lightning. Lightning flash rate and channel length measurements, obtained using the Office National d'Etudes et de Recherche Arospatiales lightning interferometer, are combined with the NOx budget to give estimates of average lightning NOx production per interferometer flash and per unit flash channel length. The analysis yields production rates of approximately 43.2 moles (2.6 × 1025 molecules) NOx per interferometer flash and 1.7 × 10−3 moles (1.0 × 1021 molecules) NOx per meter of flash channel. These production rates fall within the bounds of rates derived in previous studies using completely different approaches.