The combined HOPE & HOPE-VV campaign took place on board the Antea, off Noumea, from 3 at 11 September 2024. The three days preceding the campaign were used to prepare the 1 km long drifting line at the quayside.
The scientific team on board was made up of: Maxime Arnaud (M.I.O), Amandine Delepierre (IMAGO), Emmanuel de Saint Leger (DT-INSU), Olivier Grosso (M.I.O), Frédéric Le Moigne (LEMAR), Anne Petrenko (M.I.O, mission leader), Matthieu Savarino (M.I.O) and Damien Vignon (IMAGO) and the shore team was made up of : Sophie Bonnet (M.I.O), Mercedes Jardin-Camps (M.I.O), Jordan Duchene-Candido (M.I.O, IRD Nouméa), Mathieu Gentil (M.I.O), Stéphanie Barrillon (M.I.O), Jean-Luc Fuda (M.I.O) and Louise Rousselet (M.I.O).
Various operations were successfully carried out: deployments of the Free-Fall ADCP (with a Nortek Sentinel 500 kHz 5-beam ADCP to measure vertical velocities), CTD, Marine Snow Catcher (to study different fractions of marine snow as a function of its falling speed at various depths) and the deployment of a 1000 m drifting line made up of 16 sediment traps to study biogeochemistry, OMICS and others equipped with polyacrylamide gels and cryogels to examine the composition of the flow, the origin of particles and possibly decipher the export routes of diazotrophs.
At the same time Socratescarried out on land with water collected in the vicinity of the mooring, has made it possible to trace the fate of carbon and nitrogen in the food web, right down to the faecal pellets, the vector for exports to the deep sea.
Analyses are therefore underway.... We'll be back in the next episode with more information on carbon export to the seabed and vertical velocity measurements.
