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

Abstract

NO x 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 NO x produced by the storm was transported out into the anvil. The analyzed NO x flux into the anvil, combined with results from a cloud model simulation, indicate that approximately 60 percent of the NO x 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 NO x budget to give estimates of average lightning NO x production per interferometer flash and per unit flash channel length. The analysis yields production rates of approximately 43.2 moles (2.6 × 10 25 molecules) NO x per interferometer flash and 1.7 × 10 −3 moles (1.0 × 10 21 molecules) NO x per meter of flash channel. These production rates fall within the bounds of rates derived in previous studies using completely different approaches.