Multi-variate probability density functions with dynamics for cloud droplet activation in large-scale models: single column tests

Abstract. Successful simulation of cloud-aerosol interactions (indirect aerosol effects) in climate models requires relating grid-scale aerosol, dynamic, and thermodynamic fields to small-scale processes like aerosol activation. A turbulence and cloud parameterization, based on multi-variate probability density functions of sub-grid vertical velocity, temperature, and moisture, has been extended to treat aerosol activation. Multi-variate probability density functions with dynamics (MVD PDFs) offer a solution to the problem of the gap between the resolution of climate models and the scales relevant for aerosol activation and a means to overcome the limitations of diagnostic estimates of cloud droplet number concentration based only on aerosol concentration. Incorporated into the single-column version of GFDL AM3, the MVD PDFs successfully simulate cloud properties including precipitation for cumulus, stratocumulus, and cumulus-under-stratocumulus. The extension to treat aerosol activation predicts droplet number concentrations in good agreement with large eddy simulations (LES). The droplet number concentrations from the MVD PDFs match LES results more closely than diagnostic relationships between aerosol concentration and droplet concentration. In the single-column model simulations, as aerosol concentration increases, droplet concentration increases, precipitation decreases, but liquid water path can increase or decrease.

[1]  J. Golaz,et al.  Two-moment bulk stratiform cloud microphysics in the GFDL AM3 GCM: description, evaluation, and sensitivity tests , 2010 .

[2]  Ramaswamy,et al.  The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3 , 2011 .

[3]  A. Slingo,et al.  Clouds in the Perturbed Climate System , 2010 .

[4]  C. Bretherton,et al.  Large-Eddy Simulations of a Drizzling, Stratocumulus-Topped Marine Boundary Layer , 2009 .

[5]  Ernst Strüngmann Forum,et al.  Clouds in the perturbed climate system : their relationship to energy balance, atmospheric dynamics, and precipitation , 2009 .

[6]  B. Stevens,et al.  Understanding macrophysical outcomes of microphysical choices in simulations of shallow cumulus convection , 2008 .

[7]  Andrew Gettelman,et al.  A new two-moment bulk stratiform cloud microphysics scheme in the Community Atmosphere Model, version 3 (CAM3). Part I: Description and numerical tests , 2008 .

[8]  Sungsu Park,et al.  A single-column model intercomparison of a heavily drizzling stratocumulus-topped boundary layer , 2007 .

[9]  Vincent E. Larson,et al.  Elucidating Model Inadequacies in a Cloud Parameterization by Use of an Ensemble-Based Calibration Framework , 2007 .

[10]  Jeffrey T. Kiehl,et al.  Twentieth century climate model response and climate sensitivity , 2007 .

[11]  Paul Ginoux,et al.  Modeling the interactions between aerosols and liquid water clouds with a self-consistent cloud scheme in a general circulation model , 2007 .

[12]  C. Bretherton,et al.  Cloud droplet sedimentation, entrainment efficiency, and subtropical stratocumulus albedo , 2007 .

[13]  V. Ramaswamy,et al.  A New Parameterization of Cloud Droplet Activation Applicable to General Circulation Models , 2006 .

[14]  I. Musat,et al.  On the contribution of local feedback mechanisms to the range of climate sensitivity in two GCM ensembles , 2006 .

[15]  S. Klein,et al.  Using Stochastically Generated Subcolumns to Represent Cloud Structure in a Large-Scale Model , 2005 .

[16]  Vincent E. Larson,et al.  Supplying Local Microphysics Parameterizations with Information about Subgrid Variability: Latin Hypercube Sampling , 2005 .

[17]  J. Golaz,et al.  Coamps®-Les: Model Evaluation and Analysis of Second-and Third-Moment Vertical Velocity Budgets , 2005 .

[18]  C. Bretherton,et al.  Intercomparison and interpretation of single-column model simulations of a nocturnal stratocumulus-topped marine boundary layer , 2005 .

[19]  S. Ghan,et al.  Parallel simulations of aerosol influence on clouds using cloud‐resolving and single‐column models , 2005 .

[20]  C. Bretherton,et al.  Evaluation of Large-Eddy Simulations via Observations of Nocturnal Marine Stratocumulus , 2005 .

[21]  V. Larson,et al.  Using Probability Density Functions to Derive Consistent Closure Relationships among Higher-Order Moments , 2005 .

[22]  B. Stevens,et al.  Observations of Drizzle in Nocturnal Marine Stratocumulus , 2005 .

[23]  M. Kirkpatrick,et al.  The impact of humidity above stratiform clouds on indirect aerosol climate forcing , 2004, Nature.

[24]  A. P. Siebesma,et al.  A Large Eddy Simulation Intercomparison Study of Shallow Cumulus Convection , 2003 .

[25]  D. Lilly,et al.  Supplement to Dynamics and Chemistry of Marine Stratocumulus—DYCOMS-II , 2003 .

[26]  D. Lilly,et al.  Dynamics and chemistry of marine stratocumulus - DYCOMS II , 2003 .

[27]  Vincent E. Larson,et al.  A PDF-Based Model for Boundary Layer Clouds. Part II: Model Results , 2002 .

[28]  W. Cotton,et al.  Small-Scale and Mesoscale Variability in Cloudy Boundary Layers: Joint Probability Density Functions , 2002 .

[29]  Vincent E. Larson,et al.  A PDF-Based Model for Boundary Layer Clouds. Part I: Method and Model Description , 2002 .

[30]  David A. Randall,et al.  Toward a Unified Parameterization of the Boundary Layer and Moist Convection. Part I: A New Type of Mass-Flux Model , 2001 .

[31]  K.,et al.  Simulations of Trade Wind Cumuli under a Strong Inversion , 2001 .

[32]  Leo J. Donner,et al.  Three-Dimensional Cloud-System Modeling of GATE Convection , 1999 .

[33]  Ulrike Lohmann,et al.  Erratum: ``Prediction of the number of cloud droplets in the ECHAM GCM'' , 1999 .

[34]  L. Ruby Leung,et al.  Prediction of cloud droplet number in a general , 1997 .

[35]  R. Hodur.  The Naval Research Laboratory’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) , 1997 .

[36]  Joyce E. Penner,et al.  An assessment of the radiative effects of anthropogenic sulfate , 1997 .

[37]  David A. Randall,et al.  Single-Column Models and Cloud Ensemble Models as Links between Observations and Climate Models , 1996 .

[38]  B. Stevens,et al.  Elements of the microphysical structure of numerically simulated nonprecipitating stratocumulus , 1996 .

[39]  U. Lohmann,et al.  The sulfate-CCN-cloud albedo effect: a sensitivity study with two general circulation models , 1996 .

[40]  Olivier Boucher,et al.  The sulfate‐CCN‐cloud albedo effect , 1995 .

[41]  M. Lemone.  Some Observations of Vertical Velocity Skewness in the Convective Planetary Boundary Layer , 1990 .

[42]  R. Rotunno,et al.  Vertical-Velocity Skewness in the Buoyancy-Driven Boundary Layer , 1990 .

[43]  B. Albrecht.  Aerosols, Cloud Microphysics, and Fractional Cloudiness , 1989, Science.

[44]  Robert A. Houze,et al.  The Contribution of Mesoscale Motions to the Mass and Heat Fluxes of an Intense Tropical Convective System , 1980 .

[45]  George L. Mellor,et al.  The Gaussian Cloud Model Relations , 1977 .

[46]  J. Hansen,et al.  A parameterization for the absorption of solar radiation in the earth's atmosphere , 1974 .