A cloud scheme for data assimilation: Description and initial tests

A new cloud scheme has been developed specifically for the purposes of variational data assimilation, a task complicated by the inherent nonlinearity of many cloud processes. The aim was to retain the most important features of the ECMWF nonlinear cloud scheme, while removing much of the complexity and as many of the discrete transitions as possible. The scheme thus retains a simplified link to convective detrainment, and uses a similar formulation for the production of precipitation. A flexible statistical cloud scheme approach is used, where the diagnosis of stratiform cloud fraction and condensate amount depend on assumptions concerning subgrid‐scale fluctuations. A novel aspect of the new scheme is the treatment of precipitation evaporation that specifically takes this subgrid distribution of humidity variability into account.

[1]  Philippe Lopez,et al.  The capability of 4D‐Var systems to assimilate cloud‐affected satellite infrared radiances , 2004 .

[2]  P. Bauer,et al.  Variational retrieval of temperature and humidity profiles using rain rates versus microwave brightness temperatures , 2004 .

[3]  J. Mahfouf,et al.  Jacobians of an operational prognostic cloud scheme , 2003 .

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

[5]  Jean-Jacques Morcrette,et al.  Preliminary studies on the variational assimilation of cloud–radiation observations , 2002 .

[6]  M. Tanguay,et al.  Linearization of a simplified planetary boundary layer parameterization , 2002 .

[7]  Jean-Jacques Morcrette,et al.  Linearized radiation and cloud schemes in the ECMWF model: Development and evaluation , 2002 .

[8]  A. Tompkins.  A Prognostic Parameterization for the Subgrid-Scale Variability of Water Vapor and Clouds in Large-Scale Models and Its Use to Diagnose Cloud Cover , 2002 .

[9]  F. Chevallier,et al.  Model Clouds as Seen from Space: Comparison with Geostationary Imagery in the 11-μm Window Channel , 2002 .

[10]  Jean-Jacques Morcrette,et al.  Assessment of the ECMWF Model Cloudiness and Surface Radiation Fields at the ARM SGP Site , 2002 .

[11]  C. Jakob.  Ice clouds in numerical weather prediction models: progress, problems, and prospects , 2002 .

[12]  Philippe Lopez,et al.  Implementation and validation of a new prognostic large‐scale cloud and precipitation scheme for climate and data‐assimilation purposes , 2002 .

[13]  Kerry Emanuel,et al.  A Parameterization of the Cloudiness Associated with Cumulus Convection; Evaluation Using TOGA COARE Data , 2001 .

[14]  Joao Teixeira.  Cloud Fraction and Relative Humidity in a Prognostic Cloud Fraction Scheme , 2001 .

[15]  Stephen A. Klein,et al.  A parametrization of the effects of cloud and precipitation overlap for use in general‐circulation models , 2000 .

[16]  C. Jakob,et al.  Revision of convection, radiation and cloud schemes in the ECMWF integrated forecasting system , 2000 .

[17]  M. Khairoutdinov,et al.  A New Cloud Physics Parameterization in a Large-Eddy Simulation Model of Marine Stratocumulus , 2000 .

[18]  Christian Jakob,et al.  Cloud Cover in the ECMWF Reanalysis , 1999 .

[19]  Jean-François Mahfouf,et al.  Influence of physical processes on the tangent‐linear approximation , 1999 .

[20]  Jean-Noël Thépaut,et al.  Simplified and Regular Physical Parameterizations for Incremental Four-Dimensional Variational Assimilation , 1999 .

[21]  Adrian Simmons,et al.  Stratospheric water vapour and tropical tropopause temperatures in Ecmwf analyses and multi‐year simulations , 1999 .

[22]  P. Courtier,et al.  Extended assimilation and forecast experiments with a four‐dimensional variational assimilation system , 1998 .

[23]  P. Brown,et al.  Evaluation of key microphysical parameters in three‐dimensional cloud‐model simulations using aircraft and multiparameter radar data , 1997 .

[24]  H. Barker.  A parameterization for computing grid-averaged solar fluxes for inhomogeneous marine boundary layer , 1996 .

[25]  Ulrike Lohmann,et al.  Design and performance of a new cloud microphysics scheme developed for the ECHAM general circulation model , 1996 .

[26]  Philippe Courtier,et al.  Sensitivity of forecast errors to initial conditions , 1996 .

[27]  P. Courtier,et al.  A strategy for operational implementation of 4D‐Var, using an incremental approach , 1994 .

[28]  K. D. Beheng.  A parameterization of warm cloud microphysical conversion processes , 1994 .

[29]  C. Walcek.  Cloud Cover and Its Relationship to Relative Humidity during a Springtime Midlatitude Cyclone , 1994 .

[30]  J. Royer,et al.  A statistical cloud scheme for use in an AGCM , 1993 .

[31]  M. Tiedtke,et al.  Representation of Clouds in Large-Scale Models , 1993 .

[32]  W. S. Lewellen,et al.  Binormal Model of Ensemble Partial Cloudiness , 1993 .

[33]  S. Ghan,et al.  Computationally Efficient Approximations to Stratiform Cloud Microphysics Parameterization , 1992 .

[34]  Zhaoxin Li,et al.  Sensitivity of an atmospheric general circulation model to prescribed SST changes: feedback effects associated with the simulation of cloud optical properties , 1991 .

[35]  R. Smith.  A scheme for predicting layer clouds and their water content in a general circulation model , 1990 .

[36]  J. Kristjánsson,et al.  Condensation and Cloud Parameterization Studies with a Mesoscale Numerical Weather Prediction Model , 1989 .

[37]  M. Tiedtke.  A Comprehensive Mass Flux Scheme for Cumulus Parameterization in Large-Scale Models , 1989 .

[38]  H. D. Orville,et al.  Bulk Parameterization of the Snow Field in a Cloud Model , 1983 .

[39]  Stephen J. Lord,et al.  Interaction of a Cumulus Cloud Ensemble with the Large-Scale Environment. Part III: Semi-Prognostic Test of the Arakawa-Schubert Cumulus Parameterization , 1982 .

[40]  P. Bougeault,et al.  Modeling the Trade-Wind Cumulus Boundary Layer. Part I: Testing the Ensemble Cloud Relations Against Numerical Data. , 1981 .

[41]  Hilding Sundqvist,et al.  A parameterization scheme for non-convective condensation including prediction of cloud water content , 1978 .

[42]  J. Deardorff,et al.  Subgrid-Scale Condensation in Models of Nonprecipitating Clouds , 1977 .

[43]  E. Kessler.  On the distribution and continuity of water substance in atmospheric circulations , 1969 .

[44]  J. Mahfouf,et al.  The ECMWF operational implementation of four‐dimensional variational assimilation. II: Experimental results with improved physics , 2022 .