Evaluation of deep convective transport in storms from different convective regimes during the DC3 field campaign using WRF‐Chem with lightning data assimilation

Abstract

Deep convective transport of surface moisture and pollution from the planetary boundary layer to the upper troposphere and lower stratosphere affects the radiation budget and climate. This study analyzes the deep convective transport in three different convective regimes from the 2012 Deep Convective Clouds and Chemistry field campaign: 21 May Alabama air mass thunderstorms, 29 May Oklahoma supercell severe storm, and 11 June mesoscale convective system (MCS). Lightning data assimilation within the Weather Research and Forecasting (WRF) model coupled with chemistry (WRF‐Chem) is utilized to improve the simulations of storm location, vertical structure, and chemical fields. Analysis of vertical flux divergence shows that deep convective transport in the 29 May supercell case is the strongest per unit area, while transport of boundary layer insoluble trace gases is relatively weak in the MCS and air mass cases. The weak deep convective transport in the strong MCS is unexpected and is caused by the injection into low levels of midlevel clean air by a strong rear inflow jet. In each system, the magnitude of tracer vertical transport is more closely related to the vertical distribution of mass flux density than the vertical distribution of trace gas mixing ratio. Finally, the net vertical transport is strongest in high composite reflectivity regions and dominated by upward transport.

Effects of Scavenging, Entrainment, and Aqueous Chemistry on Peroxides and Formaldehyde in Deep Convective Outflow Over the Central and Southeast United States

“…In this paper, we use aircraft and radar observations from DC3 combined with high‐resolution Weather Research and Forecasting model with Chemistry (WRF‐Chem, Grell et al, ; Fast et al, ) simulations to gain more insight into how ice retention interacts with other microphysical, dynamical, and chemical processes affecting reductions in mixing ratios of CH 3 OOH, CH 2 O, and H 2 O 2 . We focus our analysis on storms in Oklahoma and Alabama and a mesoscale convective system (MCS) over Arkansas/Missouri/Illinois/Mississippi because these storms have been successfully simulated with WRF‐Chem (Bela et al, ; Li et al, ; Phoenix et al, ; Yang et al, ); because the three storms differ greatly in updraft velocities, storm intensity, storm size, and other factors; and because we can build upon findings from semiidealized modeling studies (e.g., Barth et al, ; Mari et al, ; Salzmann et al, ) and DC3 (Barth et al, ; Bela et al, ; Fried et al, ).…”

The kinematic and microphysical control of lightning rate, extent, and NOX production

“…Ultimately, these relationships can be used to parameterize LNO X in numerical cloud models lacking explicit prediction of cloud electrical and lightning processes [e.g., However, it is important to note that these aircraft observations are not usable for comparison to the storm analyzed here because of the following reasons: (1) The NASA DC-8 aircraft only sampled the storm for 13 min (from 2117 to 2130 UTC) with one loop through the anvil at one altitude (11.5 km), which is not sufficient to characterize lightning NO X production and (2) the National Science Foundation/National Center for Atmospheric Research Gulfstream-V (NSF/NCAR-GV) aircraft only sampled downwind of the storm at 10 km for 25 min (from 2050 to 2115 UTC), but smaller NO X values were found close to the storm than farther downwind, indicating the likely influence of other upwind storms, thus making these observations unusable for an LNO X analysis for the storm of interest [Pollack et al, 2016]. In addition, other members of the DC3 group have, and are currently in the process of analyzing storms in Colorado, Oklahoma, and Alabama and are either using the LNO X observations to develop a measurement-based range for NO X production (such as Pollack et al [2016]) or doing Weather Research and Forecasting (WRF) modeling coupled with chemistry (i.e., WRF-Chem modeling [Li et al, 2014[Li et al, , 2016) and therefore it was decided to not duplicate this work. Also, this study closely follows that of MEA15 in that the same convective storm, together with the same dual-Doppler radar, NALMA and NLDN data are used.…”

Simulation of Chemical Transport by Typhoon Mireille (1991)

“…For example, Mireille's net water vapor flux was similar to that of Ingrid (Allison et al, 2018). Values of CO transport (i.e., flux density and concentration) also compared well to middle-latitude convection over East Asia (Klich & Fuelberg, 2014) and the central United States (Li et al, 2017).…”