Analysis of cloud-resolving simulations of a tropical mesoscale convective system observed during TWP-ICE: Vertical fluxes and draft properties in convective and stratiform regions

Agnieszka A. Mrowiec, Catherine Rio, Ann M. Fridlind, Andrew S. Ackerman, Anthony D. Del Genio, Olivier M. Pauluis, Adam C. Varble, Jiwen Fan

Research output: Contribution to journalArticle

Abstract

We analyze three cloud-resolving model simulations of a strong convective event observed during the TWP-ICE campaign, differing in dynamical core, microphysical scheme or both. Based on simulated and observed radar reflectivity, simulations roughly reproduce observed convective and stratiform precipitating areas. To identify the characteristics of convective and stratiform drafts that are difficult to observe but relevant to climate model parameterization, independent vertical wind speed thresholds are calculated to capture 90% of total convective and stratiform updraft and downdraft mass fluxes. Convective updrafts are fairly consistent across simulations (likely owing to fixed large-scale forcings and surface conditions), except that hydrometeor loadings differ substantially. Convective downdraft and stratiform updraft and downdraft mass fluxes vary notably below the melting level, but share similar vertically uniform draft velocities despite differing hydrometeor loadings. All identified convective and stratiform downdrafts contain precipitation below ∼10 km and nearly all updrafts are cloudy above the melting level. Cold pool properties diverge substantially in a manner that is consistent with convective downdraft mass flux differences below the melting level. Despite differences in hydrometeor loadings and cold pool properties, convective updraft and downdraft mass fluxes are linearly correlated with convective area, the ratio of ice in downdrafts to that in updrafts is ∼0.5 independent of species, and the ratio of downdraft to updraft mass flux is ∼0.5-0.6, which may represent a minimum evaporation efficiency under moist conditions. Hydrometeor loading in stratiform regions is found to be a fraction of hydrometeor loading in convective regions that ranges from ∼10% (graupel) to ∼90% (cloud ice). These findings may lead to improved convection parameterizations.

Original languageEnglish (US)
Article numberD19201
JournalJournal of Geophysical Research: Space Physics
Volume117
Issue number18
DOIs
StatePublished - 2012

Fingerprint

vertical air currents
draft
convective system
updraft
hydrometeors
simulation
cold pool
melting
parameterization
graupel
ice clouds
ice
climate models
analysis
reflectivity
radar
climate modeling
convection
evaporation
wind velocity

ASJC Scopus subject areas

  • Atmospheric Science
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this

Analysis of cloud-resolving simulations of a tropical mesoscale convective system observed during TWP-ICE : Vertical fluxes and draft properties in convective and stratiform regions. / Mrowiec, Agnieszka A.; Rio, Catherine; Fridlind, Ann M.; Ackerman, Andrew S.; Del Genio, Anthony D.; Pauluis, Olivier M.; Varble, Adam C.; Fan, Jiwen.

In: Journal of Geophysical Research: Space Physics, Vol. 117, No. 18, D19201, 2012.

Research output: Contribution to journalArticle

Mrowiec, Agnieszka A. ; Rio, Catherine ; Fridlind, Ann M. ; Ackerman, Andrew S. ; Del Genio, Anthony D. ; Pauluis, Olivier M. ; Varble, Adam C. ; Fan, Jiwen. / Analysis of cloud-resolving simulations of a tropical mesoscale convective system observed during TWP-ICE : Vertical fluxes and draft properties in convective and stratiform regions. In: Journal of Geophysical Research: Space Physics. 2012 ; Vol. 117, No. 18.
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