Publisher: Direction – Updated on 14/12/2020
The DYNOTROP team is built around a common object of study: the tropical oceans.
The team is interested in the dynamics of ocean currents at regional and basin scales, and in scale interactions. It is interested in the processes operating in the ocean surface layer, including fine-scale processes, and studies how the properties of this surface layer affect ocean-atmosphere interactions. Finally, it focuses on oceanic and atmospheric teleconnections to/from the subtropics, in relation to the dominant modes of variability in the tropics. The study of these modes of variability on interannual and decadal scales (ENSO (El Nino Southern Oscillation), IOD (Indian Ocean Dipole), PDO (Pacific decadal Oscillation), Atlantic zonal and meridional modes) is an important contextual element.
The research of the team is organized around 4 main axes:
- Tropical ocean dynamics: circulation and scale interactions (from finescales to basin scales). What are the mechanisms that govern the dynamics and variability of currents in the tropical band at different spatial (regional to basin) and temporal (sub-inertial to decadal) scales?
- The ocean surface layer and the ocean-atmosphere coupling. What are the processes that govern the variability of ocean surface layer properties (in terms of current shear, temperature, salinity, heat content, stratification, chlorophyll,…)? What are the impacts on ocean-atmosphere exchanges and on extreme events?
- Tropical-subtropical interactions. What are the mechanisms and impacts of oceanic and atmospheric teleconnections between the tropics and subtropics?
- Use and impact of observations in operational systems. Which sustained observing systems in the tropical Pacific and Atlantic oceans will be needed in the coming years to meet the needs of both research and operational forecasting systems?
Strategy and tools
To answer these questions, the DYNOTROP team relies on a wide range of tools, including numerical modeling, collection of in situ observations, and analysis of in situ and space-based observations. It is responsible for two National Observation Services – the Global Ocean Surface Salinity Network (SNO SSS) and the Tropical Atlantic Moorings Network (SNO PIRATA) – and has organized several cruises in the Tropical Atlantic (annual PIRATA cruises) and in the Southwest Tropical Pacific (MoorSPICE, CASSIOPEE).
The team is also involved in international observations projects (TPOS2020, TAOS). It is a user and producer of in situ data (organization of oceanographic cruises, deployment of gliders, moorings, Argo floats, drifters).
Team members also use satellite data (Jason altimetry satellites, AltiKa, Sentinel-3, MODIS water color satellites, etc…) and are involved in the definition and use of satellite missions, such as SMOS, SWOT and STREAM.
In terms of modeling, the researchers use and implement numerical simulations with community ocean models (NEMO, CROCO, SCHISM), atmospheric models (simple “in-house” model DREAM), coupled AO (WRF, SIMBAD), and coupled physical-biogeochemical (PISCES, BIO-EBUS). The team implements regional simulations for its needs, and develops numerical modeling tools for hydrodynamic connections between river mouths and the tropical ocean.
These issues are relevant to all three tropical basins.
In the tropical Atlantic, the study regions are the Amazon river plume, and the western boundary current system off Brazil; the cold tongue of the equatorial upwelling and the Gulf of Guinea, key regions for the African climate; the Benguela upwelling, and the “Benguela Nino” phenomenon; the Caribbean Sea and the Gulf of Mexico, where complex mesoscale and submesoscale structures interact.
In the Tropical Pacific, the study regions are the Southwest Pacific and the western boundary current system of the Solomon Sea; the frontal region north of the equatorial cold tongue; and the Northeast Tropical Pacific, a tropical cyclone generation zone.
In the Indian Ocean, the study region is the Bay of Bengal.
This research relies heavily on southern partnerships strengthened in particular during long-term assignments of team members. These partnerships exist with Benin, South Africa, Mexico, Brazil, as well as New Caledonia, and the University of the South Pacific in Fiji.
|First name LAST NAME||Grade – Employer|
|Sophie CRAVATTE||Team leader|
Research Scientist – IRD
|Gaël ALORY||Assistant Physicist – CNAP|
|Rachid BENSHILA||Research Engineer – CNRS|
|Fabien DURAND||Research Scientist – IRD|
|Alexandre GANACHAUD||Senior Scientist – IRD|
|Lionel GOURDEAU||Senior Scientist – IRD|
|Nicholas HALL||Professor – UT3|
|Fabrice HERNANDEZ||Research Scientist – IRD|
|Séréna ILLIG-THEVENIN||Research Scientist – IRD|
|Julien JOUANNO||Research Scientist – IRD|
|Elodie KESTENARE||Research Engineer – IRD|
|Jérôme LLIDO||Research Engineer – IRD|
|Guillaume MORVAN||Engineer – IRD|
|Lionel RENAULT||Research Scientist – IRD|
|Philippe TECHINE||Research Engineer – CNRS|