Project Title

Initiation of the Antarctic slope front in West Antarctica

Summary

Event Number:
O-124-N

Program Manager:
Dr. Peter Milne

ASC POC/Implementer:
David Rivera / Bruce Felix

Principal Investigator(s)

Dr. Andrew F Thompson
andrewt@caltech.edu
California Institute of Technology
Geological and Planetary Sciences
Pasadena, California

Location

Supporting Stations: RV/IB Nathaniel B. Palmer
Research Locations: Bellingshausen and Amundsen Seas

Description

The Antarctic Slope Front (ASF) is a persistent, V-shaped feature of the continental shelf and slope around much of Antarctica. It is a notable, yet under-sampled component of Southern Ocean circulation. The ASF is a primary source region for the renewal of Antarctic surface water from below and also bottom water flow into the global deep ocean. There is considerable interest in understanding the exchanges and transformations of ASF ocean heat, gases, salt, nutrients, particulates, and carbon through exchanges with components of the high-latitude ocean, polar atmosphere, sea ice, and land ice. This project will conduct a survey of the frontal circulation along the continental shelf break and the major troughs of the Bellingshausen Sea using both ocean gliders and ship-based instruments.

Field Season Overview

Two team members will sail on the RV/IB Nathaniel B. Palmer from Punta Arenas, Chile. The main focus of their work will be to deploy two gliders. Both gliders will sample the continental slope and the continental shelf in the western Bellingshausen Sea, and then from the western edge of the Belgica Trough before flying westward towards the eastern side of the Amundsen Sea. Each deployment will take approximately six hours. The gliders will sample for a period of roughly six weeks before being recovered by the NBP on its return route back to Punta Arenas. The team will also collect high-resolution Conductivity Temperature Depth (CTD) and Lowered Acoustic Doppler Current Profiler (LADCP) measurements to map the structure of the Antarctic Slope Front between the Bellingshausen and Amundsen Seas. This project is a continuation of work that was begun on cruise NBP19-01.

Deploying Team Members