• Armstrong, R. L., and M. J. Brodzik, 2001: Recent Northern Hemisphere snow extent: A comparison of data derived from visible and microwave satellite sensors. Geophys. Res. Lett., 28, 36733676.

    • Search Google Scholar
    • Export Citation
  • Bitner, D., T. Carroll, D. Cline, and P. Romanov, 2002: An assessment of the differences between three satellite snow cover mapping techniques. Hydrol. Processes, 16, 37233733.

    • Search Google Scholar
    • Export Citation
  • Blyth, E., and Coauthors, 2006: JULES: A new community land surface model. Global Change Newsletter, No. 66, International Geosphere–Biosphere Programme, The Royal Swedish Academy of Sciences, Stockholm, Sweden, 9–11. [Available online at http://www.igbp.net/documents/NL_66-3.pdf.]

    • Search Google Scholar
    • Export Citation
  • Brasnett, B., 1999: A global analysis of snow depth for numerical weather prediction. J. Appl. Meteor., 38, 726740.

  • Brubaker, K. L., R. T. Pinker, and E. Deviatova, 2005: Evaluation and comparison of MODIS and IMS snow-cover estimates for the continental United States using station data. J. Hydrometeor., 6, 10021017.

    • Search Google Scholar
    • Export Citation
  • Cameron, J., 2003: Comparison of Unified Model snow and sea-ice fields with NESDIS and USAF data sets. Forecasting Research Tech. Rep. 416, Met Office, 40 pp.

    • Search Google Scholar
    • Export Citation
  • Davies, T., M. J. P. Cullen, A. J. Malcolm, M. H. Mawson, A. Staniforth, A. A. White, and N. Wood, 2005: A new dynamical core for the Met Office’s global and regional modelling of the atmosphere. Quart. J. Roy. Meteor. Soc., 131, 17591782.

    • Search Google Scholar
    • Export Citation
  • Drusch, M., D. Vasiljevic, and P. Viterbo, 2004: ECMWF’s global snow analysis: Assessment and revision based on satellite observations. J. Appl. Meteor., 43, 12821294.

    • Search Google Scholar
    • Export Citation
  • Essery, R., E. Martin, H. Douville, A. Fernández, and E. Brun, 1999: A comparison of four snow models using observations from an alpine site. Climate Dyn., 15, 583593.

    • Search Google Scholar
    • Export Citation
  • Hall, D. K., 1988: Assessment of polar climate change using satellite technology. Rev. Geophys., 26, 2639.

  • Hall, D. K., G. A. Riggs, J. L. Foster, and S. V. Kumar, 2010: Development and evaluation of a cloud-gap-filled MODIS daily snow-cover product. Remote Sens. Environ., 114, 496503, doi:10.1016/j.rse.2009.10.007.

    • Search Google Scholar
    • Export Citation
  • Helfrich, S. R., D. McNamara, B. H. Ramsay, T. Baldwin, and T. Kasheta, 2007: Enhancements to, and forthcoming developments in the Interactive Multisensor Snow and Ice Mapping System (IMS). Hydrol. Processes, 21, 15761586.

    • Search Google Scholar
    • Export Citation
  • Maurer, E. P., J. D. Rhoads, R. O. Dubayah, and D. P. Lettenmaier, 2003: Evaluation of the snow-covered area data product from MODIS. Hydrol. Processes, 17, 5971.

    • Search Google Scholar
    • Export Citation
  • Nolin, A. W., and S. Liang, 2000: Progress in bidirectional reflectance modelling and applications for surface particulate media: Snow and soils. Remote Sens. Rev., 18, 307342.

    • Search Google Scholar
    • Export Citation
  • Ramsay, B. H., 1998: The Interactive Multisensor Snow and Ice Mapping System. Hydrol. Processes, 12, 15371546.

  • Rodell, M., and P. R. Houser, 2004: Updating a land surface model with MODIS-derived snow cover. J. Hydrometeor., 5, 10641075.

  • Romanov, P., G. Gutman, and I. Csiszar, 2000: Automated monitoring of snow cover over North America with multispectral satellite data. J. Appl. Meteor., 39, 18661880.

    • Search Google Scholar
    • Export Citation
  • Romanov, P., D. Tarpley, G. Gutman, and T. Carroll, 2003: Mapping and monitoring of the snow cover fraction over North America. J. Geophys. Res., 108, 8619, doi:10.1029/2002JD003142.

    • Search Google Scholar
    • Export Citation
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Using Satellite-Derived Snow Cover Data to Implement a Snow Analysis in the Met Office Global NWP Model

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  • 1 Met Office, Exeter, United Kingdom
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Abstract

Snow cover and amount are important components in the interaction between the land surface and atmosphere, but until recently there has been no observational snow information incorporated into the Met Office global numerical weather prediction (NWP) model. This paper presents a Northern Hemisphere (NH) snow analysis, based on satellite-derived observations of snow cover, that has recently been implemented in the operational global Unified Model (UM). The analysis uses daily snow maps from the NOAA National Environmental Satellite Data and Information Service Interactive Multisensor Snow and Ice Mapping System (IMS) to modify the UM background snow amount. Assimilation experiments carried out during the NH snow accumulation and ablation periods show improvements in analyzed snow cover, both qualitatively and quantitatively, when compared with unmodified control runs. Although the effect on forecast accuracy of introducing the snow analysis is largely neutral, there is some evidence of small improvements in screen-level temperature and humidity forecasts. Retention of information introduced by the snow analysis is hard, and so the limited impact on forecast accuracy is not unexpected. Several methods of validation and verification are presented, and their results and implications are discussed. The NH snow analysis delivers a basic snow assimilation system that can be expanded and developed further in future iterations to improve the representation of snow cover and amount in global and regional forecasting models.

Corresponding author address: Samantha Pullen, Met Office, FitzRoy Rd., Exeter EX1 3PB, United Kingdom. E-mail: samantha.pullen@metoffice.gov.uk

Abstract

Snow cover and amount are important components in the interaction between the land surface and atmosphere, but until recently there has been no observational snow information incorporated into the Met Office global numerical weather prediction (NWP) model. This paper presents a Northern Hemisphere (NH) snow analysis, based on satellite-derived observations of snow cover, that has recently been implemented in the operational global Unified Model (UM). The analysis uses daily snow maps from the NOAA National Environmental Satellite Data and Information Service Interactive Multisensor Snow and Ice Mapping System (IMS) to modify the UM background snow amount. Assimilation experiments carried out during the NH snow accumulation and ablation periods show improvements in analyzed snow cover, both qualitatively and quantitatively, when compared with unmodified control runs. Although the effect on forecast accuracy of introducing the snow analysis is largely neutral, there is some evidence of small improvements in screen-level temperature and humidity forecasts. Retention of information introduced by the snow analysis is hard, and so the limited impact on forecast accuracy is not unexpected. Several methods of validation and verification are presented, and their results and implications are discussed. The NH snow analysis delivers a basic snow assimilation system that can be expanded and developed further in future iterations to improve the representation of snow cover and amount in global and regional forecasting models.

Corresponding author address: Samantha Pullen, Met Office, FitzRoy Rd., Exeter EX1 3PB, United Kingdom. E-mail: samantha.pullen@metoffice.gov.uk
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