CA 12-13 XXVIII ita. Esp. South Africa

Extract from the Italian XXVIII antarctic expedition report

The S/A Agulhas II has left the Cape Town harbor on the 06/12/2012, bound for the Antarctic continent, then reached on 17/12/2012. XBT launches started a few hours after the departure and continued throughout the GoodHope Line, the route covered by the Agulhas II toward Antarctica (fig. 1).

Fig. 1: Map of XBT launches in the period 6-15/12/2012 (left) and section of temperature relative to the 0-900m layer, from Cape Town to Antarctica (right).

During the first leg, from Cape Town to Antarctica, 157 XBT were launched (13 did not work properly) at a resolution of about 20nm. XBT activities were conducted between 33.86°S/17.88°E (06/12/2012 at 21:57) and 69.10°S/0.12°W (15/12/2012 at 13:10) when the sea ice conditions forced interruption of the measurements.
The XBT casts were also used for inter-calibration of the data collected by other instruments such as surveys CTD near the ice shelf, water column profiles realized by 15 ARGO floats and 3 Seagliders as well as with data collected continuously from thermosalinograph on board (TSG). After quality control process a reliable section of temperature of the first 900m along the Line GoodHope has been realized (Fig.1).
The section of temperature obtained through the use of XBT probes allowed so to identify the location of the main fronts thermhoaline of the Antarctic Circumpolar Current (ACC).
The day10/02/2012, the S/A Agulhas II left Antarctica direct to Cape Town, reached on 19/02/2012. 148 XBT (27 malfunctioning) were launched along the route (Figure 2) always at a resolution of 90 minutes (about 20 nautical miles) .

Fig. 2 Map of XBT launches in the period 11-19/12/2013 along the Antarctica-Cape Town transect (left) and temperature section relative to the layer 0-900m (right).