A Stochastic Framework for Modeling the Population Dynamics of Convective Clouds
A stochastic prognostic framework for modeling the population dynamics of convective clouds and representing them in climate models is proposed. The framework follows the nonequilibrium statistical mechanical approach to constructing a master equation for representing the evolution of the number of convective cells of a specific size and their associated cloudbase mass flux, given a largescale forcing. In this framework, referred to as STOchastic framework for Modeling Population dynamics of convective clouds (STOMP), the evolution of convective cell size is predicted from three key characteristics of convective cells: (i) the probability of growth, (ii) the probability of decay, and (iii) the cloudbase mass flux. STOMP models are constructed and evaluated against CPOL radar observations at Darwin and convection permitting model (CPM) simulations. Multiple models are constructed under various assumptions regarding these three key parameters and the realisms of these models are evaluated. It is shown that in a model where convective plumes prefer to aggregate spatially and the cloudbase mass flux is a nonlinear function of convective cell area, the mass flux manifests a rechargedischarge behavior under steady forcing. Such a model also produces observed behavior of convective cell populations and CPM simulated cloudbase mass flux variability under diurnally varyingmore »
 Authors:

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 Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
 Univ. of Reading (United Kingdom). Dept. of Meteorology
 Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences
 Publication Date:
 Report Number(s):
 PNNLSA133047
Journal ID: ISSN 19422466; TRN: US1801830
 Grant/Contract Number:
 AC0576RL01830
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Advances in Modeling Earth Systems
 Additional Journal Information:
 Journal Volume: 10; Journal Issue: 1; Journal ID: ISSN 19422466
 Publisher:
 American Geophysical Union (AGU)
 Research Org:
 Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 54 ENVIRONMENTAL SCIENCES; stochastic; nonequilibrium; parameterization; population dynamics; convection
 OSTI Identifier:
 1423628
Hagos, Samson, Feng, Zhe, Plant, Robert S., Houze, Robert A., and Xiao, Heng. A Stochastic Framework for Modeling the Population Dynamics of Convective Clouds. United States: N. p.,
Web. doi:10.1002/2017ms001214.
Hagos, Samson, Feng, Zhe, Plant, Robert S., Houze, Robert A., & Xiao, Heng. A Stochastic Framework for Modeling the Population Dynamics of Convective Clouds. United States. doi:10.1002/2017ms001214.
Hagos, Samson, Feng, Zhe, Plant, Robert S., Houze, Robert A., and Xiao, Heng. 2018.
"A Stochastic Framework for Modeling the Population Dynamics of Convective Clouds". United States.
doi:10.1002/2017ms001214. https://www.osti.gov/servlets/purl/1423628.
@article{osti_1423628,
title = {A Stochastic Framework for Modeling the Population Dynamics of Convective Clouds},
author = {Hagos, Samson and Feng, Zhe and Plant, Robert S. and Houze, Robert A. and Xiao, Heng},
abstractNote = {A stochastic prognostic framework for modeling the population dynamics of convective clouds and representing them in climate models is proposed. The framework follows the nonequilibrium statistical mechanical approach to constructing a master equation for representing the evolution of the number of convective cells of a specific size and their associated cloudbase mass flux, given a largescale forcing. In this framework, referred to as STOchastic framework for Modeling Population dynamics of convective clouds (STOMP), the evolution of convective cell size is predicted from three key characteristics of convective cells: (i) the probability of growth, (ii) the probability of decay, and (iii) the cloudbase mass flux. STOMP models are constructed and evaluated against CPOL radar observations at Darwin and convection permitting model (CPM) simulations. Multiple models are constructed under various assumptions regarding these three key parameters and the realisms of these models are evaluated. It is shown that in a model where convective plumes prefer to aggregate spatially and the cloudbase mass flux is a nonlinear function of convective cell area, the mass flux manifests a rechargedischarge behavior under steady forcing. Such a model also produces observed behavior of convective cell populations and CPM simulated cloudbase mass flux variability under diurnally varying forcing. Finally, in addition to its use in developing understanding of convection processes and the controls on convective cell size distributions, this modeling framework is also designed to serve as a nonequilibrium closure formulations for spectral mass flux parameterizations.},
doi = {10.1002/2017ms001214},
journal = {Journal of Advances in Modeling Earth Systems},
number = 1,
volume = 10,
place = {United States},
year = {2018},
month = {2}
}