A first description of the Antarctic Peninsula Coastal Current

Abstract

Abstract We present hydrographic and shipboard ADCP data collected during the fall (April/June) and winter (July/August) and moored velocity observations collected from 2001 to early 2002 on the west Antarctic Peninsula (wAP) shelf during the Southern Ocean Global Ecosystems Dynamics (SO GLOBEC) program. In fall, a geostrophically balanced, buoyant current flows southward along the coast. This Antarctic Peninsula Coastal Current (APCC) forms during the ice-free season and extends from Adelaide Island to Alexander Island, although its path inside Marguerite Bay is uncertain. During the fall of 2001, the APCC had a volume transport of 0.32 ± 0.13 Sv and a freshwater transport (relative to a reference salinity of 34.4) of 126 ± 50 km 3 yr - 1 . From early July to late October, the APCC disappears from the coast as the freshwater input from the coast diminishes and sea-ice forms on the shelf. An examination of the relative sizes of the freshwater sources suggests runoff from land and precipitation over the ocean are the primary sources for the APCC.