The kinematic and microphysical control of lightning rate, extent, and NOX production. Issue 13 (12th July 2016)

• Record Type: Journal Article
• Authors: Carey, Lawrence D.; Koshak, William; Peterson, Harold; Mecikalski, Retha M.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 13(2016)
• Page Start: 7975
• Page End: 7989
• Publication Date: 2016-07-12
• Subjects: lightning -- flash rate -- flash extent -- NOx production -- radar -- LMA; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2015JD024703
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: This study investigates the kinematic and microphysical control of lightning properties, particularly those that may govern the production of nitrogen oxides (NO X = NO + NO2 ) via lightning (LNO X ), such as flash rate, type, and extent. The NASA Lightning Nitrogen Oxides Model (LNOM) is applied to lightning observations following multicell thunderstorms through their lifecycle in a Lagrangian sense over Northern Alabama on 21 May 2012 during the Deep Convective Clouds and Chemistry (DC3) experiment. LNOM provides estimates of flash rate, type, channel length distributions, channel segment altitude distributions (SADs), and LNO X production profiles. The LNOM‐derived lightning characteristics and LNO X production are compared to the evolution of radar‐inferred updraft and precipitation properties. Intercloud, intracloud (IC) flash SAD comprises a significant fraction of the total (IC + cloud‐to‐ground [CG]) SAD, while increased CG flash SAD at altitudes >6 km occurs after the simultaneous peaks in several thunderstorm properties (i.e., total [IC + CG] and IC flash rate, graupel volume/mass, convective updraft volume, and maximum updraft speed). At heights <6 km, the CG LNO X production dominates the column‐integrated total LNO X production. Unlike the SAD, total LNO X production consists of a more equal contribution from IC and CG flashes for heights >6 km. Graupel volume/mass, updraft volume, and maximum updraft speed are all well correlated to the total flash rate (correlation coefficient, ρ ≥ 0.8) but are less correlated to total flash extent ( ρ ≥ 0.6) and total LNO X production ( ρ ≥ 0.5). Although LNOM transforms lightning observations into LNO X production values, these values are estimates and are subject to further independent validation. Key Points: NASA LNOM and radar combined provide a useful new approach for studying the dynamical control of lightning properties and LNO X production Flash extent and NO X production are not as well correlated to dynamical properties as flash rate Majority of NO X production is from ground flashes despite larger cloud flash extent and rates