Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models

Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models

Show other versions (1)

<p>In the current global climate models (GCMs), the nonlinearity effect of subgrid cloud variations on the parameterization of warm-rain process, e.g., the autoconversion rate, is often treated by multiplying the resolved-scale warm-rain process rates by a so-called enhancement factor (EF). In...

Full description

Bibliographic Details
Main Authors: Z. Zhang, Q. Song, D. B. Mechem, V. E. Larson, J. Wang, Y. Liu, M. K. Witte, X. Dong, P. Wu
Format: Article
Language:English
Published: Copernicus Publications 2021-03-01
Series:Atmospheric Chemistry and Physics
Online Access:https://acp.copernicus.org/articles/21/3103/2021/acp-21-3103-2021.pdf
id doaj-fad033a1e36944c3b1c5146b4ffe6696
record_format Article
spelling doaj-fad033a1e36944c3b1c5146b4ffe66962021-03-02T06:29:11ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242021-03-01213103312110.5194/acp-21-3103-2021Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate modelsZ. Zhang0Z. Zhang1Q. Song2Q. Song3D. B. Mechem4V. E. Larson5J. Wang6Y. Liu7M. K. Witte8M. K. Witte9X. Dong10P. Wu11P. Wu12Department of Physics, University of Maryland Baltimore County (UMBC), Baltimore, 21250, USAJoint Center for Earth Systems Technology, UMBC, Baltimore, 21250, USADepartment of Physics, University of Maryland Baltimore County (UMBC), Baltimore, 21250, USAJoint Center for Earth Systems Technology, UMBC, Baltimore, 21250, USADepartment of Geography and Atmospheric Science, University of Kansas, Lawrence, 66045, USADepartment of Mathematical Sciences, University of Wisconsin – Milwaukee, Milwaukee, 53201, USACenter for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, 63130, USAEnvironmental and Climate Science Department, Brookhaven National Laboratory, Upton, 11973, USAJoint Institute for Regional Earth System Science and Engineering, University of California Los Angeles, Los Angeles, 90095, USAJet Propulsion Laboratory, California Institute of Technology, Pasadena, 91011, USADepartment of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, 85721, USADepartment of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, 85721, USAPacific Northwest National Laboratory, Richland, WA 99354, USA<p>In the current global climate models (GCMs), the nonlinearity effect of subgrid cloud variations on the parameterization of warm-rain process, e.g., the autoconversion rate, is often treated by multiplying the resolved-scale warm-rain process rates by a so-called enhancement factor (EF). In this study, we investigate the subgrid-scale horizontal variations and covariation of cloud water content (<span class="inline-formula"><i>q</i><sub>c</sub></span>) and cloud droplet number concentration (<span class="inline-formula"><i>N</i><sub>c</sub></span>) in marine boundary layer (MBL) clouds based on the in situ measurements from a recent field campaign and study the implications for the autoconversion rate EF in GCMs. Based on a few carefully selected cases from the field campaign, we found that in contrast to the enhancing effect of <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> variations that tends to make EF <span class="inline-formula">&gt;</span> 1, the strong positive correlation between <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> results in a suppressing effect that tends to make EF <span class="inline-formula">&lt;</span> 1. This effect is especially strong at cloud top, where the <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> correlation can be as high as 0.95. We also found that the physically complete EF that accounts for the covariation of <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> is significantly smaller than its counterpart that accounts only for the subgrid variation of <span class="inline-formula"><i>q</i><sub>c</sub></span>, especially at cloud top. Although this study is based on limited cases, it suggests that the subgrid variations of <span class="inline-formula"><i>N</i><sub>c</sub></span> and its correlation with <span class="inline-formula"><i>q</i><sub>c</sub></span> both need to be considered for an accurate simulation of the autoconversion process in GCMs.</p>https://acp.copernicus.org/articles/21/3103/2021/acp-21-3103-2021.pdf
collection DOAJ
language English
format Article
sources DOAJ
author Z. Zhang
Z. Zhang
Q. Song
Q. Song
D. B. Mechem
V. E. Larson
J. Wang
Y. Liu
M. K. Witte
M. K. Witte
X. Dong
P. Wu
P. Wu
spellingShingle Z. Zhang
Z. Zhang
Q. Song
Q. Song
D. B. Mechem
V. E. Larson
J. Wang
Y. Liu
M. K. Witte
M. K. Witte
X. Dong
P. Wu
P. Wu
Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
Atmospheric Chemistry and Physics
author_facet Z. Zhang
Z. Zhang
Q. Song
Q. Song
D. B. Mechem
V. E. Larson
J. Wang
Y. Liu
M. K. Witte
M. K. Witte
X. Dong
P. Wu
P. Wu
author_sort Z. Zhang
title Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
title_short Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
title_full Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
title_fullStr Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
title_full_unstemmed Vertical dependence of horizontal variation of cloud microphysics: observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
title_sort vertical dependence of horizontal variation of cloud microphysics: observations from the ace-ena field campaign and implications for warm-rain simulation in climate models
publisher Copernicus Publications
series Atmospheric Chemistry and Physics
issn 1680-7316
1680-7324
publishDate 2021-03-01
description <p>In the current global climate models (GCMs), the nonlinearity effect of subgrid cloud variations on the parameterization of warm-rain process, e.g., the autoconversion rate, is often treated by multiplying the resolved-scale warm-rain process rates by a so-called enhancement factor (EF). In this study, we investigate the subgrid-scale horizontal variations and covariation of cloud water content (<span class="inline-formula"><i>q</i><sub>c</sub></span>) and cloud droplet number concentration (<span class="inline-formula"><i>N</i><sub>c</sub></span>) in marine boundary layer (MBL) clouds based on the in situ measurements from a recent field campaign and study the implications for the autoconversion rate EF in GCMs. Based on a few carefully selected cases from the field campaign, we found that in contrast to the enhancing effect of <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> variations that tends to make EF <span class="inline-formula">&gt;</span> 1, the strong positive correlation between <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> results in a suppressing effect that tends to make EF <span class="inline-formula">&lt;</span> 1. This effect is especially strong at cloud top, where the <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> correlation can be as high as 0.95. We also found that the physically complete EF that accounts for the covariation of <span class="inline-formula"><i>q</i><sub>c</sub></span> and <span class="inline-formula"><i>N</i><sub>c</sub></span> is significantly smaller than its counterpart that accounts only for the subgrid variation of <span class="inline-formula"><i>q</i><sub>c</sub></span>, especially at cloud top. Although this study is based on limited cases, it suggests that the subgrid variations of <span class="inline-formula"><i>N</i><sub>c</sub></span> and its correlation with <span class="inline-formula"><i>q</i><sub>c</sub></span> both need to be considered for an accurate simulation of the autoconversion process in GCMs.</p>
url https://acp.copernicus.org/articles/21/3103/2021/acp-21-3103-2021.pdf
work_keys_str_mv AT zzhang verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT zzhang verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT qsong verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT qsong verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT dbmechem verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT velarson verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT jwang verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT yliu verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT mkwitte verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT mkwitte verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT xdong verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT pwu verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
AT pwu verticaldependenceofhorizontalvariationofcloudmicrophysicsobservationsfromtheaceenafieldcampaignandimplicationsforwarmrainsimulationinclimatemodels
_version_ 1724242168867979264

Similar Items