Open AccessA Model-Based Decomposition of the Sea Ice–Atmosphere Feedback over the Barents Sea during Winter
Author(s) -
Jessica Liptak,
Courtenay Strong
Publication year - 2014
Publication title -
journal of climate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.315
H-Index - 287
eISSN - 1520-0442
pISSN - 0894-8755
DOI - 10.1175/jcli-d-13-00371.1
Subject(s) - atmosphere (unit) , forcing (mathematics) , sea ice , advection , climatology , environmental science , positive feedback , atmospheric sciences , flux (metallurgy) , geology , sea ice growth processes , atmospheric model , sea surface temperature , sea ice thickness , arctic ice pack , oceanography , meteorology , materials science , geography , physics , engineering , electrical engineering , metallurgy , thermodynamics
The feedback between Barents Sea ice and the winter atmosphere was studied in a modeling framework by decomposing it into two sequential boundary forcing experiments. The Community Ice Code (CICE) model was initialized with anomalously high sea ice concentration (SIC) over the Barents Sea and forced with an atmosphere produced by positive SIC anomalies, and CICE was initialized with low Barents Sea SIC and forced with an atmosphere produced by negative SIC anomalies. Corresponding control runs were produced by exposing the same SIC initial conditions to climatological atmospheres, and the monthly mean sea ice response showed a positive feedback over the Barents Sea for both experiments: the atmosphere produced by positive SIC anomalies increased SIC over the Barents Sea during the winter, and the atmosphere produced by negative SIC anomalies decreased SIC. These positive feedbacks were driven primarily by thermodynamic forcing from surface longwave flux anomalies and were weakened somewhat by atmospheric temperature advection. Dynamical effects also opposed the positive feedback, with enhanced surface wind stress divergence over the Barents Sea in the high-SIC case and enhanced convergence in the low-SIC case.