A coupled ice‐ocean model of a wind‐driven coastal flow

Abstract

Ice movement driven by winds along the coast is studied using a two‐dimensional (vertical seaward), ice‐ocean coupled model. Right‐hand alongshore winds are given when internal ice stresses are important to determine the ice movement. These winds induce right‐hand coastal currents and ice movement. A shoreward Ekman flow beneath the ice is a major mechanism to constrain the ice over the shelf, balancing the internal ice pressure gradient. When the wind ceases, the ice decreases its alongshore velocity, and the ice‐covered band becomes wider. The alongshore ice velocity is sensitive to ice shear strength, which determines the shear stress at the coast; i.e., weak (strong) shear strength allows a large (small) ice velocity at the coast, resulting in intense (weak) Ekman flow and downwelling, which induces a fast (slow) coastal current. The alongshore velocity is also sensitive to the relatively small cross‐shore component of the wind; i.e., the seaward (shoreward) component reduces (induces) the shear stress and allows large (small) ice velocity. The results are applied to the ice over the Labrador shelf.