Role of Surface Friction on Shallow Nonprecipitating Convection

Park, Seung-Bu; Böing, Steven; Gentine, Pierre

doi:10.1175/JAS-D-17-0106.1

Title: Role of Surface Friction on Shallow Nonprecipitating Convection

Abstract

The role of surface friction on shallow nonprecipitating convection is investigated using a series of large-eddy simulations with varying surface friction velocity and with a cloud identification algorithm. As surface friction intensifies, convective rolls dominate over convective cells and secondary overturning circulation becomes stronger in the subcloud layer, thus transporting more moisture upward and more heat downward between the subcloud and cloud layers. Identifying individual clouds, using the identification algorithm based on a three-dimensional topological analysis, reveals that intensified surface friction increases the number of clouds and the degree of tilting in the downstream direction. Highly intensified surface friction increases wind shear across the cloud base and induces cloud tilting, which leads to a vertically parabolic profile of liquid water mixing ratio instead of the classical two-layer structure (conditionally unstable and trade inversion layers). Furthermore, cloud tilting induces more cloud cover and more cloud mass flux much above the cloud base (e.g., 0.8 < z < 1.2 km), but less cloud cover and less cloud mass flux in the upper cloud layer (e.g., z > 1.2 km) because of increased lateral entrainment rate. Similarly, profiles of directly measured entrainment and detrainment rates show that detrainment in the lower cloud layermore »« less

Authors:

Park, Seung-Bu ^[1]; Böing, Steven ^[2]; Gentine, Pierre ^[3]

Department of Earth and Environmental Engineering, Columbia University, New York, New York, and Institute for Basic Science Center for Climate Physics, Pusan National University, Busan, South Korea
School of Earth and Environment, University of Leeds, Leeds, United Kingdom
Department of Earth and Environmental Engineering, and Earth Institute, Columbia University, New York, New York

Publication Date:: Mon Jan 01 00:00:00 EST 2018

Research Org.:: Columbia Univ., New York, NY (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1415522

Alternate Identifier(s):: OSTI ID: 1541820

Grant/Contract Number:: SC0014203; SC0011094

Resource Type:: Published Article

Journal Name:: Journal of the Atmospheric Sciences

Additional Journal Information:: Journal Name: Journal of the Atmospheric Sciences Journal Volume: 75 Journal Issue: 1; Journal ID: ISSN 0022-4928

Publisher:: American Meteorological Society

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; Meteorology & Atmospheric Sciences

Citation Formats


                    Park, Seung-Bu, Böing, Steven, and Gentine, Pierre. Role of Surface Friction on Shallow Nonprecipitating Convection.  United States: N. p., 2018. 
Web.  doi:10.1175/JAS-D-17-0106.1.

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                    Park, Seung-Bu, Böing, Steven, & Gentine, Pierre. Role of Surface Friction on Shallow Nonprecipitating Convection.  United States.  https://doi.org/10.1175/JAS-D-17-0106.1

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                    Park, Seung-Bu, Böing, Steven, and Gentine, Pierre. Mon .  
"Role of Surface Friction on Shallow Nonprecipitating Convection".  United States.  https://doi.org/10.1175/JAS-D-17-0106.1.

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@article{osti_1415522,

  title        = {Role of Surface Friction on Shallow Nonprecipitating Convection},

  author       = {Park, Seung-Bu and Böing, Steven and Gentine, Pierre},

  abstractNote = {The role of surface friction on shallow nonprecipitating convection is investigated using a series of large-eddy simulations with varying surface friction velocity and with a cloud identification algorithm. As surface friction intensifies, convective rolls dominate over convective cells and secondary overturning circulation becomes stronger in the subcloud layer, thus transporting more moisture upward and more heat downward between the subcloud and cloud layers. Identifying individual clouds, using the identification algorithm based on a three-dimensional topological analysis, reveals that intensified surface friction increases the number of clouds and the degree of tilting in the downstream direction. Highly intensified surface friction increases wind shear across the cloud base and induces cloud tilting, which leads to a vertically parabolic profile of liquid water mixing ratio instead of the classical two-layer structure (conditionally unstable and trade inversion layers). Furthermore, cloud tilting induces more cloud cover and more cloud mass flux much above the cloud base (e.g., 0.8 < z < 1.2 km), but less cloud cover and less cloud mass flux in the upper cloud layer (e.g., z > 1.2 km) because of increased lateral entrainment rate. Similarly, profiles of directly measured entrainment and detrainment rates show that detrainment in the lower cloud layer becomes smaller with stronger surface friction.},

  doi          = {10.1175/JAS-D-17-0106.1},

  journal      = {Journal of the Atmospheric Sciences},

  number       = 1,

  volume       = 75,

  place        = {United States},

  year         = {Mon Jan 01 00:00:00 EST 2018},

  month        = {Mon Jan 01 00:00:00 EST 2018}

}

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Works referencing / citing this record:

Land–atmosphere interactions in the tropics – a review
journal, January 2019

Gentine, Pierre; Massmann, Adam; Lintner, Benjamin R.
Hydrology and Earth System Sciences, Vol. 23, Issue 10
DOI: 10.5194/hess-23-4171-2019

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Title: Role of Surface Friction on Shallow Nonprecipitating Convection

Abstract

Citation Formats

Land–atmosphere interactions in the tropics – a review journal, January 2019

Land–atmosphere interactions in the tropics – a review
journal, January 2019