Numerical simulations of the July 10 Stratospheric‐Tropospheric Experiment: Radiation, Aerosols, and Ozone/Deep Convection Experiment convective system: Kinematics and transport

Abstract

Abstract. The observed July 10, 1996, Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone (STERAO)convective system is broadly reproduced in a nonhydrostatic cloud model simulation using an idealized horizontally homogeneous sounding and no terrain. System evolution from a multicellular line to a supercell, along with line orientation, anvil structure, horizontal wind fields, depth of convection, and derived radar reflectivity, compares well with observations. Simulated passive tracer transport of CO and ozone generally agrees with aircraft measurements and shows a small amount of entrainment of environmental air in the updrafts, and a small amount of dilution occurring with transport downwind in the anvil; the entrainment and dilution are less pronounced in the supercell stage. The horizontally integrated vertical flux divergence for CO in the simulation shows a net gain at almost all levels above 8 km mean sea level (msl). The rate of increase of CO mass above 8 km varies significantly in time, with a peak at early times, followed by a decline and minimum as the system transitions to a supercell and a steady increase as the supercell matures. Trajectory analyses show that updrafts in the simulation are ingesting air from a layer spanning from 2 km to 3.5 km msl (from 0.5 to 2 km above the surface). The residence times for parcels in the updraft varies from just under 10 min to more than 20 min, with most parcels taking approximately 10 min to ascend to the anvil.

CELLS v1.0: updated and parallelized version of an electrical scheme to simulate multiple electrified clouds and flashes over large domains

“…As observed Skamarock et al, 2000), the 10 July 1996 STERAO storm simulated with Meso-NH evolved from a multicell to a supercell. Figure 2 shows the composite reflectivity (maximum radar reflectivity in a grid cell column, Z max , in dBZ) at different stages of the storm.…”

Cloud-scale model intercomparison of chemical constituent transport in deep convection

“…The simulations performed for the intercomparison mimic those described by Skamarock et al (2000) and Barth et al (2001. The environment was assumed to be homogeneous, thus a single profile was used for initialization.…”

“…Convective cloud models coupled with chemistry simulate the redistribution of passive trace gas species well (e.g. Pickering et al, 1996;Stenchikov et al, 1996;Wang and Prinn, 2000;Skamarock et al, 2000;DeCaria et al, 2000). The cloudresolving models, when incorporated with reasonably comprehensive chemistry, can also provide details of cloud processing of soluble chemical species as well as tropospheric production/destruction of short-lived species including critical hydrogen oxides precursors and aerosols influenced by the existence of convection (e.g.…”

“…The initial profiles of the meteorological data were obtained from sonde and aircraft data . To start the convection quickly so that the intercomparison could focus on chemical species transport, the convection was initiated with 3 warm bubbles (3 • C perturbation) oriented in a NW to SE line following Skamarock et al (2000). Their choice of three bubbles was based on obtaining a good representation of the storm structure and evolution (particularly the transition from a multicell storm to a quasi-supercell) with their cloud model.…”

Evaluation of a new lightning-produced NO<sub>x</sub> parameterization for cloud resolving models and its associated uncertainties

“…The simulation performed is similar to those described by Skamarock et al (2000Skamarock et al ( , 2003 and Barth et al (2001. The environment was assumed to be homogeneous, thus a single profile was used for initialization.…”