The ANDREX fieldwork consisted in theory of two sections along the northern (JC30 cruise in January 2009 on board of the RRS James Cook) and eastern (US CLIVAR I6S repeat section on board the RV Roger Revelle, February 2008) rims of the Weddell Gyre.
Due to a medical emergency during the JC30 cruise, the fieldwork was interrupted near 16°W and a second cruise (ANDREX recovery) was made in March-April 2010 on board of the RRS James Clark Ross to close the box between 16°W and the tip of the Antarctic Peninsula.
I6s (February 2008)
The I6s section was occupied as part of the US CLIVAR program (PI: Kevin Speer, Florida State University) and is a repeat of previously occupied section between South Africa and the Antarctic coast along the 30°E meridian. A total of 106 CTD/LADCP stations were occupied. For the ANDREX project only the southernmost stations (South of 53°S) will be used.
JC30 (January 2009)
The first leg of the ANDREX cruise (PI: Sheldon Bacon, National Oceanography Centre, Southampton) started from Cape Town on 26 December. The start of the section is a repeat of three stations occupied during the CLIVAR I6S repeat section held in February 2008. The work started on 31 December at 53.5°S 30.0°E. We moved south-westward and the work was stopped after station 27 (Figure 1) due to a medical evacuation.
JR239 (March-April 2010)
The ANDREX-recovery cruise was made in March-April 2010 (PI: Mike Meredith, British Antarctic Survey) from Montevideo to the Falkland Islands via South Georgia). The work started from the tip of the Antarctic Peninsula and moved westward along the South Scotia Ridge until the junction with the first ANDREX section was made and one station was re-occupied. During this cruise, a second section repeating part of the A23 section and a multibeam survey of the Orkney Passage were also made as part of the BAS polar ocean program. A total of 98 CTD stations were occupied during these two sections.