Article

Climate Dynamics

, Volume 30, Issue 2, pp 203-223

Open Access This content is freely available online to anyone, anywhere at any time.

An evaluation of Arctic cloud and radiation processes during the SHEBA year: simulation results from eight Arctic regional climate models

  • K. WyserAffiliated withRossby Centre, SMHI Email author 
  • , C. G. JonesAffiliated withCanadian Regional Climate Modelling and Diagnostics Network, Université du Québec à Montréal
  • , P. DuAffiliated withCanadian Regional Climate Modelling and Diagnostics Network, Université du Québec à Montréal
  • , E. GirardAffiliated withCanadian Regional Climate Modelling and Diagnostics Network, Université du Québec à Montréal
  • , U. WillénAffiliated withRossby Centre, SMHI
  • , J. CassanoAffiliated withCooperative Institute for Research in Environmental Sciences and Department of Atmospheric and Oceanic Sciences, University of Colorado
  • , J. H. ChristensenAffiliated withDanish Meteorological Institute
  • , J. A. CurryAffiliated withGeorgia Institute of Technology, School of Earth and Atmospheric Sciences
  • , K. DethloffAffiliated withAlfred Wegener Institute for Polar and Marine Research, Research Unit
    • , J.-E. HaugenAffiliated withNorwegian Meteorological Institute
    • , D. JacobAffiliated withMax Planck Institute for Meteorology
    • , M. KøltzowAffiliated withNorwegian Meteorological Institute
    • , R. LapriseAffiliated withCanadian Regional Climate Modelling and Diagnostics Network, Université du Québec à Montréal
    • , A. LynchAffiliated withSchool of Geography and Environmental Science, Monash University
    • , S. PfeiferAffiliated withMax Planck Institute for Meteorology
    • , A. RinkeAffiliated withAlfred Wegener Institute for Polar and Marine Research, Research Unit
    • , M. SerrezeAffiliated withCooperative Institute for Research in Environmental Sciences and Department of Atmospheric and Oceanic Sciences, University of Colorado
    • , M. J. ShawAffiliated withCooperative Institute for Research in Environmental Sciences and Department of Atmospheric and Oceanic Sciences, University of Colorado
    • , M. TjernströmAffiliated withRossby Centre, SMHIDepartment of Meteorology, Stockholm University
    • , M. ZagarAffiliated withRossby Centre, SMHIDepartment of Meteorology, Stockholm University

Abstract

Eight atmospheric regional climate models (RCMs) were run for the period September 1997 to October 1998 over the western Arctic Ocean. This period was coincident with the observational campaign of the Surface Heat Budget of the Arctic Ocean (SHEBA) project. The RCMs shared common domains, centred on the SHEBA observation camp, along with a common model horizontal resolution, but differed in their vertical structure and physical parameterizations. All RCMs used the same lateral and surface boundary conditions. Surface downwelling solar and terrestrial radiation, surface albedo, vertically integrated water vapour, liquid water path and cloud cover from each model are evaluated against the SHEBA observation data. Downwelling surface radiation, vertically integrated water vapour and liquid water path are reasonably well simulated at monthly and daily timescales in the model ensemble mean, but with considerable differences among individual models. Simulated surface albedos are relatively accurate in the winter season, but become increasingly inaccurate and variable in the melt season, thereby compromising the net surface radiation budget. Simulated cloud cover is more or less uncorrelated with observed values at the daily timescale. Even for monthly averages, many models do not reproduce the annual cycle correctly. The inter-model spread of simulated cloud-cover is very large, with no model appearing systematically superior. Analysis of the co-variability of terms controlling the surface radiation budget reveal some of the key processes requiring improved treatment in Arctic RCMs. Improvements in the parameterization of cloud amounts and surface albedo are most urgently needed to improve the overall performance of RCMs in the Arctic.

Keywords

Arctic climate Cloud–radiation interaction Cloud cover Longwave radiation Shortwave radiation Surface albedo