Evaluation of Trade Cumulus in the ECMWF Model with Observations from CALIPSO

Maike Ahlgrimm European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom

Search for other papers by Maike Ahlgrimm in
Current site
Google Scholar
PubMed
Close
and
Martin Köhler European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom

Search for other papers by Martin Köhler in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) are used to assess trade cumulus cloudiness in three versions of the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts. The observations are recast onto the model grid, and two simple threshold criteria for cloud-top height and cloud fraction are used to identify grid points containing trade cumulus clouds. The cloud fraction and cloud-top height distributions of the sample populations are then compared. Results show that all versions of the model overestimate the frequency of occurrence of trade cumulus clouds but underestimate their cloud fraction when present. These effects partially compensate. Cloud-top heights are overestimated in model cycles using the modified Tiedtke parameterization for shallow convection, but are in very good agreement with observations when the dual mass flux parameterization is introduced.

Corresponding author address: Maike Ahlgrimm, European Centre for Medium-Range Weather Forecasts, Shinfield Park, Reading RG2 9AX, United Kingdom. Email: maike.ahlgrimm@ecmwf.int

Abstract

Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) are used to assess trade cumulus cloudiness in three versions of the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts. The observations are recast onto the model grid, and two simple threshold criteria for cloud-top height and cloud fraction are used to identify grid points containing trade cumulus clouds. The cloud fraction and cloud-top height distributions of the sample populations are then compared. Results show that all versions of the model overestimate the frequency of occurrence of trade cumulus clouds but underestimate their cloud fraction when present. These effects partially compensate. Cloud-top heights are overestimated in model cycles using the modified Tiedtke parameterization for shallow convection, but are in very good agreement with observations when the dual mass flux parameterization is introduced.

Corresponding author address: Maike Ahlgrimm, European Centre for Medium-Range Weather Forecasts, Shinfield Park, Reading RG2 9AX, United Kingdom. Email: maike.ahlgrimm@ecmwf.int

Save
  • Ahlgrimm, M., D. Randall, and M. Köhler, 2009: Evaluating cloud frequency of occurrence and cloud-top height using spaceborne lidar observations. Mon. Wea. Rev., 137 , 42254237.

    • Search Google Scholar
    • Export Citation
  • Bechtold, P., J. Chaboureau, A. Beljaars, A. Betts, M. Köhler, M. Miller, and J-L. Redelsperger, 2004: The simulation of the diurnal cycle of convective precipitation over land in a global model. Quart. J. Roy. Meteor. Soc., 130 , 31193137. doi:10.1256/qj.03.103.

    • Search Google Scholar
    • Export Citation
  • Bechtold, P., M. Köhler, T. Jung, F. Doblas-Reyes, M. Leutbecher, M. Rodwell, F. Vitart, and G. Balsamo, 2008: Advances in simulating atmospheric variability with the ECMWF model: From synoptic to decadal time-scales. Quart. J. Roy. Meteor. Soc., 134 , 13371352.

    • Search Google Scholar
    • Export Citation
  • Beljaars, A., P. Bechtold, M. Köhler, A. Orr, and A. Tompkins, 2006: Developments in model physics after ERA-40. Proc. ECMWF/GEO Workshop on Atmospheric Reanalysis, Reading, United Kingdom, ECMWF, 81–90.

    • Search Google Scholar
    • Export Citation
  • Chepfer, H., S. Bony, D. Winker, M. Chiriaco, J. Dufresne, and G. Sèze, 2008: Use of CALIPSO lidar observations to evaluate the cloudiness simulated by a climate model. Geophys. Res. Lett., 35 , L15804. doi:10.1029/2008GL034207.

    • Search Google Scholar
    • Export Citation
  • Chiriaco, M., R. Vautard, H. Chepfer, M. Haeffelin, J. Dudhia, Y. Wanherdrick, Y. Morille, and A. Protat, 2006: The ability of MM5 to simulate ice clouds: Systematic comparison between simulated and measured fluxes and lidar/radar profiles at the SIRTA Atmospheric Observatory. Mon. Wea. Rev., 134 , 897918.

    • Search Google Scholar
    • Export Citation
  • Derbyshire, S., I. Beau, P. Bechtold, J. Grandpeix, J. Piriou, J. Redelsperger, and P. Soares, 2004: Sensitivity of moist convection to environmental humidity. Quart. J. Roy. Meteor. Soc., 130 , 30553080.

    • Search Google Scholar
    • Export Citation
  • Gibson, J., P. Kallberg, S. Uppala, A. Hernandez, A. Nomura, and E. Serrano, 1997: ERA description. ECMWF Reanalysis Project Report Series 1, 72 pp.

    • Search Google Scholar
    • Export Citation
  • Iacono, M., J. Delamere, E. Mlawer, M. Shephard, S. Clough, and W. Collins, 2008: Radiative forcing by long-lived greenhouse gases: Calculations with the AER radiative transfer models. J. Geophys. Res., 113 , D13103. doi:10.1029/2008JD009944.

    • Search Google Scholar
    • Export Citation
  • Jakob, C., 1999: Cloud cover in the ECMWF reanalysis. J. Climate, 12 , 947959.

  • Jung, T., and Coauthors, 2008: The ECMWF model climate: Recent progress through improved physical parameterizations. Proc. ECMWF Seminar on Parameterization of Subgrid Physical Processes, Reading, United Kingdom, ECMWF, 233–249.

    • Search Google Scholar
    • Export Citation
  • Köhler, M., 2005: Improved prediction of boundary layer clouds. ECMWF Newsletter, No. 104, ECMWF, Reading, United Kingdom, 18–22.

  • Neggers, R., 2009: A dual mass flux framework for boundary layer convection. Part II: Clouds. J. Atmos. Sci., 66 , 14891506.

  • Neggers, R., M. Köhler, and A. Beljaars, 2009: A dual mass flux framework for boundary layer convection. Part I: Transport. J. Atmos. Sci., 66 , 14651487.

    • Search Google Scholar
    • Export Citation
  • Nitta, T., 1975: Observational determination of cloud mass flux distributions. J. Atmos. Sci., 32 , 7391.

  • Räisänen, P., H. Barker, M. Khairoutdinov, J. Li, and D. Randall, 2004: Stochastic generation of subgrid-scale cloudy columns for large-scale models. Quart. J. Roy. Meteor. Soc., 130 , 20472067. doi:10.1256/qj.03.99.

    • Search Google Scholar
    • Export Citation
  • Rossow, W., and R. Schiffer, 1999: Advances in understanding clouds from ISCCP. Bull. Amer. Meteor. Soc., 80 , 22612287.

  • Siebesma, A., and Coauthors, 2003: A large eddy simulation intercomparison study of shallow cumulus convection. J. Atmos. Sci., 60 , 12011219.

    • Search Google Scholar
    • Export Citation
  • Simmons, A., S. Uppala, D. Dee, and S. Kobayashi, 2007: ERA-Interim: New ECMWF reanalysis products from 1989 onwards. ECMWF Newsletter, No. 110, ECMWF, Reading, United Kingdom, 25–35.

    • Search Google Scholar
    • Export Citation
  • Tiedtke, M., 1989: A comprehensive mass flux scheme for cumulus parameterization in large-scale models. Mon. Wea. Rev., 117 , 17791800.

    • Search Google Scholar
    • Export Citation
  • Tiedtke, M., 1993: Representation of clouds in large-scale models. Mon. Wea. Rev., 121 , 30403061.

  • Tompkins, A., and Coauthors, 2004: Moist physical processes in the IFS: Progress and plans. ECMWF Tech. Memo. 452, 91 pp.

  • Vaughan, M., D. Winker, and K. Powell, 2005: CALIOP algorithm theoretical basis document. Part 2: Feature detection and layer properties algorithms. NASA Langley Research Center, PC-SCI-202 Part 2, Release 1.01, 87 pp. [Available online at http://www-calipso.larc.nasa.gov/resources/project_documentation.php].

    • Search Google Scholar
    • Export Citation
  • Webb, M., C. Senior, S. Bony, and J. Morcrette, 2001: Combining ERBE and ISCCP data to assess clouds in the Hadley Centre, ECMWF, and LMD atmospheric climate models. Climate Dyn., 17 , 905922.

    • Search Google Scholar
    • Export Citation
  • Wilkinson, J., R. Hogan, A. Illingworth, and A. Benedetti, 2008: Use of a lidar forward model for global comparisons of cloud fraction between the ICESat lidar and the ECMWF model. Mon. Wea. Rev., 136 , 37423759.

    • Search Google Scholar
    • Export Citation
  • Zhang, M., and Coauthors, 2005: Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurements. J. Geophys. Res., 110 , D15S02. doi:10.1029/2004JD005021.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 406 106 2
PDF Downloads 100 24 0