The WHIRLS mission off the coast of South Africa is coming to an end. It involves two research vessels: the Marion Dufresne (MD) on the one hand, and the South African icebreaker Agulhas 2 on the other.
For a month and a half, we mainly sampled a dipole (a cyclonic and an anticyclonic vortex) separated by a front. This is a hydrological structure generated by the Aiguilles Current as it flows south of South Africa, which has significant consequences for the transport of physical and biogeochemical properties in the Atlantic.
In particular, the MD carried out hydrological measurements using the new MVP recently acquired by Sabrina Speich. Various strategies were implemented on board the Agulhas 2, including high-frequency transects involving only surface continuous sampling, short-duration stations sampled at high frequency day and night, and longer-duration stations (two transects of nine stations) where flux measurements were also taken.
Together with Karine Leblanc, we mainly contributed to the measurements of carbon and silica stocks and fluxes, whilst also taking numerous samples to study phytoplankton diversity: in particular, Karine discovered two new diatom assemblages containing Tintinidae species not yet recorded.
Today, weather permitting, we should be cross-checking the measurement results obtained using the CTD-rosette from the two vessels, which have come together for this purpose, but it is not certain that the forecast 40-knot winds will allow us to do so!
Contact : Thierry Moutin
More information
