Relationships between lightning and convective turbulence

Abstract

Total lightning has been shown to correlate well with thunderstorm dynamics. Thus, correlations may exist between in-cloud convective turbulence and total lightning activity. Over the continental United States, the NEXRAD Turbulence Detection Algorithm (NTDA) provides three-dimensional (3D) fields of in-cloud Eddy Dissipation Rate (EDR), which is a quantitative measure of turbulence. Comprehensive total lightning measurements are available in some regions of the United States such as in Northern Colorado and New Mexico. Herein, investigations of the temporal and spatial relationships of 3D total lightning and NTDA EDR measurements for non-severe single cell thunderstorms in New Mexico and severe storms in Colorado are described. Results suggest that the occurrence of moderate or greater turbulence at upper levels of storms is related to storm total lightning flash rate, though exact relationships depend on the storm type. Areas of moderate and greater turbulence are also observed to coincide with the footprint of horizontal lightning flash extents. Time series show that lighter turbulence begins to occur prior to lightning initiation in the storms and also extends past the storm’s lightning activity. Furthermore, trends of storm total moderate or greater turbulence are correlated to storm total lightning flash rate and extent. These observations are consistent with other recent studies by the authors and others that suggest that total lightning may be useful in diagnosing areas of potentially hazardous atmospheric turbulence. With the expected advent of geostationary satellite based lightning mapping in the next few years, possible relationships between lightning and turbulence characteristics might provide useful information to aviation users, particularly in oceanic or remote areas where ground-based Doppler weather radar observations are unavailable.