MAP-IO: a marine and atmospheric observatory aboard the Marion Dufresne

SUCCESS STORY ODATIS

09.04.2021

From 11 January to 8 March, the SWINGS oceanographic expedition surveyed the southwest Indian Ocean with a team of 48 scientists aboard the Marion Dufresne II to explore the Southern Ocean’s role in regulating Earth’s climate. Teams at Data Terra’s ODATIS and AERIS data hubs were also involved in some of the campaign’s studies and in the fledgling MAP-IO observatory.

Exploring the Southern Ocean with SWINGS

The SWINGS oceanographic expedition’s goal was to gain new insights into how atmospheric CO₂ is sequestered in the oceans, particularly where the chemical elements vital to storing it come from and how the oceans transport and transform them.

The Southern Ocean encircling the Antarctic is a remote, inaccessible region that plays an important and complex role in capturing and storing atmospheric CO₂. Many factors are at play, from biological activity to ocean circulation. To study these processes, we need to quantify geochemical elements—silicon, nitrates and iron, as well as radium and rare-earth elements, for example—present in minute concentrations in sea water.

SWINGS is a French contribution to the international GEOTRACES programme that has been compiling data on geochemical trace elements since 2010 with a view to building a chemical atlas of the oceans. The French assembly centre for GEOTRACES is the LEFE-CYBER geochemical database at the ODATIS data hub’s CDS-IS-IMEV in-situ data centre.

The MAP-IO project team was among the other teams working alongside the SWINGS project scientists.

Studying global changes with MAP-IO

MAP-IO (for Marion Dufresne Atmospheric Programme – Indian Ocean) is an observatory in development that aims to study ocean-atmosphere processes over the long term to gain a deeper understanding of their impacts on climate and numerical weather predictions. This programme has fitted out the Marion Dufresne II with 19 semi-autonomous measuring systems dedicated to observing the atmosphere and marine biology. MAP-IO subsequently aims to ensure retention of observations within the data hubs in line with quality standards defined by research infrastructures.

**Weather forecasting room** *©Nicolas Marquestau*t

The Marion Dufresne II ferries personnel, food, equipment and fuel to France’s sub-Antarctic islands roughly 120 days a year, sailing to remote territories like the Kerguelen Islands, the Crozet archipelago, Amsterdam Island and occasionally the Scattered Islands in the Indian Ocean. It is therefore both a transport ship and a scientific research vessel with 650 m² of laboratory space. MAP-IO takes advantage of these rotations between the French Southern and Antarctic Lands (TAAF) and survey campaigns planned by the French Oceanographic Fleet (FOF) to explore scarcely documented scientific fields of investigation over long periods in a still largely unexplored region of the globe. The repetitive routes of TAAF sailings will enable the study of seasonal and climatic trends.

These interannual observations fulfil six multidisciplinary objectives:

Document oceanic sea surface state and biological composition (phytoplankton)
Monitor global atmospheric variations, particularly in the sparsely documented Indian Ocean and Southern Ocean
Study air mass transports and redistribution of aerosols and chemical compounds in the troposphere and stratosphere
Document gas and marine aerosol emissions for atmospheric numerical prediction or climate models
Ensure open data retention
Strengthen regional climate change observation networks deployed for the ReNovRisk Cyclones and Climate Change (INTERREG-V), IOGA4MET (TAAF, Scattered Islands call for projects) and UV-Indian (INTERREG-V) programmes

MAP-IO is a consortium of eight research laboratories and 21 scientists coordinated by the LACy atmosphere and cyclones laboratory and the University of La Réunion. It is funded by the European Regional Development Fund (ERDF), a CPER regional development plan, the FOF and CNRS’s INSU national universe science institute.

The current programme is planned to run for four years. It began in September 2020 and entered its operational phase with the launch of the SWINGS mission on 11 January 2021. It will take another two to three years to develop and secure the observatory in the long term. It has to follow a dedicated quality protocol and get all of its instruments accredited. At the end of this period, if MAP-IO is accredited by CNRS/INSU, it will become the only permanent mobile observatory of its kind in the world.

Example data collected by MAP-IO during SWINGS: