IUGG 2003 Abstract
P06
The Southern Ocean (SCOR, SCAR)
Friday, July 4 AM
Location: Site B, Room 19
Presiding Chairs:A.N. Garabato, I. Ansorge
TIME [ 1100 ] [ P06/04A/B19-006 ]
MODELLING THE VARIABILITY OF THE COUPLED ICE-OCEAN SYSTEM IN THE SOUTHERN OCEAN
Ralph TIMMERMANN(Institut d'Astronomie et de Geophysique, Universite Catholique de Louvain)
Thierry FICHEFET(Institut d'Astronomie et de Geophysique, Universite Catholique de Louvain)
Hugues GOOSSE ( Institut d'Astronomie et de Geophysique, Universite Catholique de Louvain )
Seasonal and interannual variations of the sea ice cover represent oneof the most pronounced signals of variability in the world climatesystem.The freezing and melting of sea ice in the marginal seas of theSouthernOcean controls the amount and location of Antarctic Bottom Waterformation which is a major driver in the global thermohalinecirculation.The Louvain-la-Neuve sea ice model has been coupled to the OPA oceangeneral circulation model. In the ORCALIM configuration, the model isrun in a global domain with 2 degrees horizontal resolution.Model runs are forced with a combined dataset consisting of both dailyNCEP/NCAR reanalysis data and various climatologies.The annual cycle of sea ice growth and decay is realistically capturedin both hemispheres, with ice extent, thickness and drift in closeagreement with observations.While hindcast simulations for the past five decades reveal only a verysmall trend, ice volume and the ice-covered area are subject to apronounced interannual variability.The presentation sheds light on typical patterns and timescales of this variability and its effects on the large scale oceancirculation.