Sensitivity of Modeled Sea Ice to External Forcing (Drifting Station "North Pole" and NCEP Data)
Abstract
A dynamic-thermodynamic sea ice model with 50-km spatial and 24-hour temporal resolution, forced by NCEP atmospheric surface level data, and zero-dimensional thermodynamic sea ice model are used to investigate the spatial and temporal variability of sea ice cover and surface energy exchange in the Arctic Basin. The models satisfactorily reproduce the averaged characteristics of the sea ice, the sea ice extent, and the surface heat exchange for different parts of the Arctic Basin. In particular, estimates of the year-to-year difference between mean sea ice thickness in September show reasonable agreement with the essential thinning of sea ice in the Canadian Basin that Rothrock et al. (1999) found. It time the evaluation of atmospheric forcing data, namely air surface level temperature and surface wind velocity from NCEP, and cloudiness amount from Gorshkov Atlas (1983) and NCEP show large disagreement with data obtained on the drifting stations "North Pole". The numerical experiments with zero-dimensional sea ice model reveal that negative feedback between long-wave radiation balance and turbulent heat fluxes, existing in nature and reproducing in the models, artificially reduce the influence of inaccuracy of forcing parameters on the estimated sea ice thickness in winter. The absence of such feedback in summer together with strong positive surface albedo feedback determines the high sensitivity of modeled ice to prescribing forcing.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2002
- Bibcode:
- 2002AGUSMGC51A..10M
- Keywords:
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- 4504 Air/sea interactions (0312);
- 1610 Atmosphere (0315;
- 0325);
- 1635 Oceans (4203)