OISO-33
| Type | Oceanographic cruise |
|---|---|
| Set | This cruise is part of the set OISO - OCÉAN INDIEN SERVICE D'OBSERVATION |
| Ship | Marion Dufresne |
| Ship owner | TAAF |
| Dates | 23/01/2023 - 01/03/2023 |
| Chief scientist(s) | LO MONACO Claire , METZL Nicolas  , PLANCHON Frédéric |
LABORATOIRE D'OCÉANOGRAPHIE ET DU CLIMAT : EXPÉRIMENTATIONS ET APPROCHES NUMÉRIQUES - UMR 7159 Institut Pierre Simon Laplace Boîte 100 4 place Jussieu 75005 Paris +33 (1) 44 27 32 48 |
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| DOI | 10.17600/18002420 |
| Objective | Observing and understanding the seasonal, interannual and decadal variations of the oceanic carbon cycle is crucial to better estimate the global carbon budget and understand its evolution, investigate ocean acidification, and validate climate models (e.g. Global Carbon Project, Global Ocean Acidification Observation Network, IPCC). To this aim, the OISO program (Ocean Indien Service d'Observations), initiated in 1998, collects measurements of oceanic CO2 as well as hydrological and biogeochemical parameters relevant to the carbon cycle along the repeated lines of R.V. Marion Dufresne in the South-West Indian and Southern Oceans; this coverage is an important complement to the international CO2 observing system. The main objective of the OISO-33 cruise conducted in January/February 2023 was to re-occupy the transects and stations that were frequently sampled over the last 3 decades (during the GEOSECS, INDIGO, MINERVE, OISO, KEOPS, SOCLIM and SWINGS cruises). Underway surface measurements were conducted during the entire cruises using the ship pumping system. Data were also collected in the water column using a rosette-CTD (20 stations) and in situ pumps (10 stations) that were deployed in the different biogeochemical zones. These observations will allow to better understand the evolution of air-sea CO2 fluxes, the accumulation of anthropogenic CO2 and ocean acidification in response to anthropogenic CO2 emissions and climate change in key regions, notably in the Antarctic zone, including the phytoplankton bloom associated with the Kerguelen Plateau. The OISO data are also be very useful for the THEMISTO program (resp. C. Cotté, LOCEAN) that investigate the response of marine organisms to their changing environment. In addition to the usual OISO observations, complementary analyses will also be performed in order to better understand the biological pump of carbon (primary production, heterotrophic respiration and export of carbon) in the framework of the French LEFE/SOCARB projet (resp. F. Planchon, LEMAR). The OISO data will be rapidly available through the international data syntheses SOCAT, GLODAP and GOA-ON, and the SOCARB data will be included in the GEOTRACES database. For the European ERC/REFINE project (resp. H. Claustre, LOV), four floats equipped for the measurement of the six standard BGC-Argo variables as well as a UVP-6 profiler (small particles and zooplankton) were deployed to the south-west and est of Kerguelen Island.These deployments were accompanied by optical measurements using several sensors installed on the rosette. Ten ARVOR floats were also deployed at different stations south of the Subantarctic front in the framework of the ARGO-Coriolis program. Finally aerosols were collected during the whole cruise, as well as rain (7 events) in order to estimate atmospheric fluxes and the input of trace metals (resp. K. Desboeufs, LISA). |