A numerical investigation of mesoscale phenomena in the summer marginal ice zone using a simple ice-ocean coupled model
Yasushi Fukamachi
Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
Tel: 81-11-706-5483
Fax: 81-11-706-7142
yasuf@soya.lowtem.hokudai.ac.jp
The marginal ice zone (MIZ) is characterized by various characteristic mesoscale phenomena, such as fronts, ice-edge jets, and eddies. These phenomena during the melting season are investigated using a simple ice-ocean coupled model. The ice model is essentially a combination of Hakkinen's (1986) dynamic model and Hakkinen's (1987) dynamic-thermodynamic model. The ocean model is basically the same as the one-and-half layer version of the model described in McCreary etal. (1991). The model parameters are based on those observed in the Southern Ocean during summer.
When the model is forced by the surface heat flux into the open ocean, salinity gradients are genetated near the ice edge due to intense ice melting there. There are ice-edge currents associated with these salinity gradients. These currents start to meander as they grow stronger. The meandering currents exchange cold and fresh water in the ice-covered region and warm and saline water in the ice-free region, and advectice into the ice-freeregion to formice tongues. As a result, both of these effects enhance ice melting in the MIZ.
