This project is a contribution to a coordinated attempt to understand the interactions of biological and physical dynamics by developing relationships among the evolution of the antarctic winter ice and snow cover, biological habitat variability, and the seasonal progression of marine ecological processes. The work will be carried out in the context of the Southern Ocean Experiment of the Global Ocean Ecosystem Dynamics Study (Globec), a large, multi-investigator study of the winter survival strategy of krill under the antarctic sea ice in the vicinity of Marguerite Bay on the western side of the Antarctic Peninsula.
The objective of this project is to develop and deploy a series of moorings on the continental shelf off Marguerite Bay. These will include current meters, salinity and temperature sensors, zooplankton concentration, upward-looking acoustic sounders to track ice motion, and acoustic doppler current profilers. The proposed mooring design will quantify and characterize the inflowing and outflowing water masses and provide the physical component for the integrated modeling effort. The mooring data will be supplemented by instrumented drifters that track surface flow.
The water masses on the continental shelf off Marguerite Bay consist of inflowing Upper Circumpolar Deep Water, which is relatively warm, salty, oxygen-poor, and nutrient-rich. In winter atmospheric processes cool and freshen this water, and recharge it with oxygen to produce Antarctic Surface Water which is diffused seaward, and supports both a sea ice cover and a productive krill-based food web. The observations produced by this project will quantify the spatial and temporal variability of the presumed clockwise flow through the bay, and define the tidal and transient flows driven by storms and southward meanders of the Antarctic Circumpolar Current. ***
