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Title: The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection

Convective entrainment is a process that is poorly represented in existing convective parameterizations. By many estimates, convective entrainment is the leading source of error in global climate models. As a potential remedy, an Eulerian implementation of the Stochastic Parcel Model (SPM) is presented here as a convective parameterization that treats entrainment in a physically realistic and computationally efficient way. Drawing on evidence that convecting clouds comprise air parcels subject to Poisson-process entrainment events, the SPM calculates the deterministic limit of an infinite number of such parcels. For computational efficiency, the SPM groups parcels at each height by their purity, which is a measure of their total entrainment up to that height. This reduces the calculation of convective fluxes to a sequence of matrix multiplications. The SPM is implemented in a single-column model and compared with a large-eddy simulation of deep convection.
Authors:
 [1]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Earth and Planetary Science; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Climate and Ecosystem Sciences Division
Publication Date:
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Journal of Advances in Modeling Earth Systems
Additional Journal Information:
Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 1942-2466
Publisher:
American Geophysical Union (AGU)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Stochastic Parcel Model; convective parameterization
OSTI Identifier:
1414749

Romps, David M. The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection. United States: N. p., Web. doi:10.1002/2015MS000537.
Romps, David M. The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection. United States. doi:10.1002/2015MS000537.
Romps, David M. 2016. "The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection". United States. doi:10.1002/2015MS000537. https://www.osti.gov/servlets/purl/1414749.
@article{osti_1414749,
title = {The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection},
author = {Romps, David M.},
abstractNote = {Convective entrainment is a process that is poorly represented in existing convective parameterizations. By many estimates, convective entrainment is the leading source of error in global climate models. As a potential remedy, an Eulerian implementation of the Stochastic Parcel Model (SPM) is presented here as a convective parameterization that treats entrainment in a physically realistic and computationally efficient way. Drawing on evidence that convecting clouds comprise air parcels subject to Poisson-process entrainment events, the SPM calculates the deterministic limit of an infinite number of such parcels. For computational efficiency, the SPM groups parcels at each height by their purity, which is a measure of their total entrainment up to that height. This reduces the calculation of convective fluxes to a sequence of matrix multiplications. The SPM is implemented in a single-column model and compared with a large-eddy simulation of deep convection.},
doi = {10.1002/2015MS000537},
journal = {Journal of Advances in Modeling Earth Systems},
number = 1,
volume = 8,
place = {United States},
year = {2016},
month = {3}
}