Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Effective Buoyancy, Inertial Pressure, and the Mechanical Generation of Boundary Layer Mass Flux by Cold Pools

Abstract

The Davies-Jones formulation of effective buoyancy is used to define inertial and buoyant components of vertical force and to develop an intuition for these components by considering simple cases. This decomposition is applied to the triggering of new boundary layer mass flux by cold pools in a cloud-resolving simulation of radiative-convective equilibrium (RCE). The triggering is found to be dominated by inertial forces, and this is explained by estimating the ratio of the inertial forcing to the buoyancy forcing, which scales as H/h, where H is the characteristic height of the initial downdraft and h is the characteristic height of the mature cold pool's gust front. In a simulation of the transition from shallow to deep convection, the buoyancy forcing plays a dominant role in triggering mass flux in the shallow regime, but the force balance tips in favor of inertial forcing just as precipitation sets in, consistent with the RCE results.

Authors:
 [1];  [2]
+ Show Author Affiliations
  1. Univ. of California, Berkeley, CA (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division
  2. Univ. of California, Berkeley, CA (United States). Dept. of Earth and Planetary Science; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
OSTI Identifier:
1512124
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Journal of the Atmospheric Sciences
Additional Journal Information:
Journal Volume: 72; Journal Issue: 8; Journal ID: ISSN 0022-4928
Publisher:
American Meteorological Society
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Buoyancy; Cold pools; Convective clouds; Deep convection; Dynamics; Gust fronts

Citation Formats

Jeevanjee, Nadir, and Romps, David M. Effective Buoyancy, Inertial Pressure, and the Mechanical Generation of Boundary Layer Mass Flux by Cold Pools. United States: N. p., 2015. Web. doi:10.1175/JAS-D-14-0349.1.
Copy to clipboard
Jeevanjee, Nadir, & Romps, David M. Effective Buoyancy, Inertial Pressure, and the Mechanical Generation of Boundary Layer Mass Flux by Cold Pools. United States. https://doi.org/10.1175/JAS-D-14-0349.1
Copy to clipboard
Jeevanjee, Nadir, and Romps, David M. Mon . "Effective Buoyancy, Inertial Pressure, and the Mechanical Generation of Boundary Layer Mass Flux by Cold Pools". United States. https://doi.org/10.1175/JAS-D-14-0349.1. https://www.osti.gov/servlets/purl/1512124.
Copy to clipboard
@article{osti_1512124,
title = {Effective Buoyancy, Inertial Pressure, and the Mechanical Generation of Boundary Layer Mass Flux by Cold Pools},
author = {Jeevanjee, Nadir and Romps, David M.},
abstractNote = {The Davies-Jones formulation of effective buoyancy is used to define inertial and buoyant components of vertical force and to develop an intuition for these components by considering simple cases. This decomposition is applied to the triggering of new boundary layer mass flux by cold pools in a cloud-resolving simulation of radiative-convective equilibrium (RCE). The triggering is found to be dominated by inertial forces, and this is explained by estimating the ratio of the inertial forcing to the buoyancy forcing, which scales as H/h, where H is the characteristic height of the initial downdraft and h is the characteristic height of the mature cold pool's gust front. In a simulation of the transition from shallow to deep convection, the buoyancy forcing plays a dominant role in triggering mass flux in the shallow regime, but the force balance tips in favor of inertial forcing just as precipitation sets in, consistent with the RCE results.},
doi = {10.1175/JAS-D-14-0349.1},
journal = {Journal of the Atmospheric Sciences},
number = 8,
volume = 72,
place = {United States},
year = {Mon Aug 03 00:00:00 EDT 2015},
month = {Mon Aug 03 00:00:00 EDT 2015}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1175/JAS-D-14-0349.1
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 51 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: x–z cross‐sections at y = 0 of (a,c,e) Archimedean buoyancy $B$ and (b,d,f) effective buoyancy $β$= $B$ − ($∂$$z$$p$b′)/$ρ$ (both 10−2 m s−2) for Gaussian bubbles of the form Eq. 3 with $R$ = 1000 m, $H$ = 1000 m, and centre height zcm of (a,b) 2000 m,more » (c,d) 500 m, and (e,f) 0 m. Horizontal and vertical dimensions are plotted to scale, though the vertical axes in (a,b) differ from those of (c– f), and the contour is drawn at the 95th percentile value in each plot. Note the marked difference in magnitude between $B$ and $β$, how this difference becomes more pronounced as the bubble moves toward the surface, and how the maximum of $β$ stays a finite height above the surface even as the maximum of $B$ approaches z = 0.« less
All figures and tables (9 total)
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

Influence of the Subcloud Layer on the Development of a Deep Convective Ensemble
journal, September 2012

  • Böing, Steven J.; Jonker, Harm J. J.; Siebesma, A. Pier
  • Journal of the Atmospheric Sciences, Vol. 69, Issue 9
  • DOI: 10.1175/JAS-D-11-0317.1

A note on Poisson’s equation for pressure in a turbulent flow
journal, January 1981

Parameterization of the Vertical Velocity Equation for Shallow Cumulus Clouds
journal, August 2012

  • de Roode, Stephan R.; Siebesma, A. Pier; Jonker, Harm J. J.
  • Monthly Weather Review, Vol. 140, Issue 8
  • DOI: 10.1175/MWR-D-11-00277.1

Mixing in lock-release gravity currents
journal, January 1996

Improvements of an Ice-Phase Microphysics Parameterization for Use in Numerical Simulations of Tropical Convection
journal, January 1995

A Mass-Flux Scheme View of a High-Resolution Simulation of a Transition from Shallow to Deep Cumulus Convection
journal, July 2006

  • Kuang, Zhiming; Bretherton, Christopher S.
  • Journal of the Atmospheric Sciences, Vol. 63, Issue 7
  • DOI: 10.1175/JAS3723.1

Modeling turbulent flow with implicit LES
journal, January 2006

Influence of convective adjustment time scale on the tropical transient activity
journal, August 2011

Sensitivity of the simulated precipitation to changes in convective relaxation time scale
journal, January 2010

Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave
journal, July 1997

  • Mlawer, Eli J.; Taubman, Steven J.; Brown, Patrick D.
  • Journal of Geophysical Research: Atmospheres, Vol. 102, Issue D14
  • DOI: 10.1029/97JD00237

The Mean Climate of the Community Atmosphere Model (CAM4) in Forced SST and Fully Coupled Experiments
journal, July 2013

Parametric sensitivity analysis of precipitation at global and local scales in the Community Atmosphere Model CAM5
journal, April 2015

  • Qian, Yun; Yan, Huiping; Hou, Zhangshuan
  • Journal of Advances in Modeling Earth Systems, Vol. 7, Issue 2
  • DOI: 10.1002/2014MS000354

Control of deep convection by sub-cloud lifting processes: the ALP closure in the LMDZ5B general circulation model
journal, September 2012

  • Rio, Catherine; Grandpeix, Jean-Yves; Hourdin, Frédéric
  • Climate Dynamics, Vol. 40, Issue 9-10
  • DOI: 10.1007/s00382-012-1506-x

The Dry-Entropy Budget of a Moist Atmosphere
journal, December 2008

Slippery Thermals and the Cumulus Entrainment Paradox*
journal, August 2013

  • Sherwood, Steven C.; Hernández-Deckers, Daniel; Colin, Maxime
  • Journal of the Atmospheric Sciences, Vol. 70, Issue 8
  • DOI: 10.1175/JAS-D-12-0220.1

Mechanisms for convection triggering by cold pools
journal, March 2015

  • Torri, Giuseppe; Kuang, Zhiming; Tian, Yang
  • Geophysical Research Letters, Vol. 42, Issue 6
  • DOI: 10.1002/2015GL063227

Vertical velocity in shallow convection for different plume types
journal, June 2014

  • Wang, Xiaocong; Zhang, Minghua
  • Journal of Advances in Modeling Earth Systems, Vol. 6, Issue 2
  • DOI: 10.1002/2014MS000318
    Sort by:
    [ × clear filter / sort ]

    Works referencing / citing this record:

    Moisture Distributions in Tropical Cold Pools From Equatorial Indian Ocean Observations and Cloud-Resolving Simulations
    journal, October 2018

    • Chandra, Arunchandra S.; Zuidema, Paquita; Krueger, Steven
    • Journal of Geophysical Research: Atmospheres, Vol. 123, Issue 20
    • DOI: 10.1029/2018jd028634

    Sensitivity of Radiative‐Convection Equilibrium to Divergence Damping in GFDL‐FV3‐Based Cloud‐Resolving Model Simulations
    journal, July 2018

    • Anber, Usama M.; Jeevanjee, Nadir; Harris, Lucas M.
    • Journal of Advances in Modeling Earth Systems, Vol. 10, Issue 7
    • DOI: 10.1029/2017ms001225

    A Numerical Study of Convection Initiation Associated With a Gust Front in Bohai Bay Region, North China
    journal, December 2019

    • Abulikemu, Abuduwaili; Wang, Yan; Gao, Runxiang
    • Journal of Geophysical Research: Atmospheres, Vol. 124, Issue 24
    • DOI: 10.1029/2019jd030883

    GoAmazon2014/5 campaign points to deep-inflow approach to deep convection across scales
    journal, April 2018

    • Schiro, Kathleen A.; Ahmed, Fiaz; Giangrande, Scott E.
    • Proceedings of the National Academy of Sciences, Vol. 115, Issue 18
    • DOI: 10.1073/pnas.1719842115

    Ongoing Breakthroughs in Convective Parameterization
    journal, April 2019

    • Rio, Catherine; Del Genio, Anthony D.; Hourdin, Frédéric
    • Current Climate Change Reports, Vol. 5, Issue 2
    • DOI: 10.1007/s40641-019-00127-w

    Tracking the Gust Fronts of Convective Cold Pools
    journal, November 2019

    • Fournier, Marielle B.; Haerter, Jan O.
    • Journal of Geophysical Research: Atmospheres, Vol. 124, Issue 21
    • DOI: 10.1029/2019jd030980

    A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment
    journal, November 2017

    Tracking the Gust Fronts of Convective Cold Pools
    text, January 2020

      Sort by:
      [ × clear filter / sort ]

      Figures / Tables found in this record:

      Figure 1 (p. 3)figure
      Figure 2 (p. 7)figure
      Figure 3 (p. 8)figure
      Figure 4 (p. 9)figure
      Figure 5 (p. 10)figure
      Figure 6 (p. 12)figure
      Figure 7 (p. 15)figure
      Figure 8 (p. 16)figure
      Figure 9 (p. 18)figure
        [ × clear filter / sort ]
        Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

        Similar Records in DOE PAGES and OSTI.GOV collections: