A numerical study of the western Cosmonaut polynya in a coupled ocean-sea ice model

摘要: [1] Employing results from a 0.4°, 40-level fully global, coupled ocean–sea ice model, we investigated the role of physical processes emanating atmosphere, ocean, and in initiation, maintenance, termination sensible heat polynya with focus on western Cosmonaut that occurred during May–July 1999. The first appeared early May 1999 form an ice-free embayment, transformed into enclosed 5–9 July, disappeared by late when surrounding regions began to encircle embayment. Except for differences concentrations, time appearance, size, shape simulated model are approximate agreement Special Sensor Microwave/Imager (SSM/I) observations. Between July Sea experienced two synoptic storms, both lasting ∼5 days. Followed passage storm 12–19 June, there was remarkable growth size embayment 21 × 103 km2. Associated this, sea surface temperature (SST) rose 0.15°C, upward flux jumped 5 94 W m−2, net freshwater ocean increased 2 cm d−1. By running simulation 20% wind speed increase, it is demonstrated twofold increase SST area 15 km2 decreased concentration approximately 10% control run. A similar, but somewhat weaker event took place 30 June 10 had less influence although (65 m−2) comparable event. examining vertical displacement −1.6°C isotherm depth prior to, during, after these demonstrate impetus provided storms able raise m through wind-driven mixing, making sufficient oceanic input beneath mixed layer available prevent freezing and/or delay formation while adjacent continued grow. sudden shift drift direction southwest northeast (3 July) followed second storm, accompanied large air-sea differences, caused enclosure subsequent polynya, its termination.