Six weeks in Antarctica, 2009

CRUISE BY RRS ERNEST SHACKLETON TO THE WEDDELL SEA, ANTARCTICA

Photo: Helge Bryhni

Text by: Ilker Fer 

Together with scientists from UK and USA, Ilker Fer, Helge Bryhni and Kjersti L. Daae participated in the cruise of RRS Ernest Shackleton to undertake physical oceanographic activities in the northern Weddell Sea, in the southern Weddell Sea and near Brunt Ice Shelf. The cruise is operated by the British Antarctic Survey with chief-scientist Dr. Keith Nicholls. Four projects are served during the cruise, one of which is the IPY project Bi-Polar Atlantic Thermohaline Circulation (BIAC). We collected data relevant to the Antarctic component of BIAC and deployed 5 heavily instrumented moorings across the continental slope in the Eastern Weddell Sea. Planned recovery of the moorings is in 2010. Additionally we conducted several days of survey from the ship using CTD and lowered-ADCP profiling as well as a deep microstructure profiler.

The Royal Research Ship, RRS Ernst Shackelton.  Photo: Helge Bryhni

Following the departure from Falklands on 23 January, and a short stop near Signy Islands to deliver 3 sceintist to the research station we carried the first part of the scientific programme, mainly comprising smapling of hydrography and mooring work. ES arrives at Halley (Brunt Ice Shelf) to uplift pax and waste. Departure from Halley will be followed by a stop at Signy Island to close base, uplift pax and waste.

The densest water mass of the world oceans is the Antarctic Bottom Water- a very important component of the global thermohaline circulation. The Weddell Sea is a major contributor to the Antarctic Bottom Water production. As the source waters from the shelves make their way down the continental slope towards the deep blue, they mix (in their temperature and salinity properties) with the surrounding water. This mixing is undersampled and not very well understood despite the major influence on the end-water properties. From our dedicated sampling at the site, we aim to increase our understanding of the processes that modify the water masses on the continental slope of the Weddell Sea. If successful, the data set, both moored and shipboard, will be unique and will increase the state-of-the-art significantly.

 For cruise report, click here

By:
20-11 2009