Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

Climate impacts on environmental systemsBox 3.1Making the right observationsThe very large heat capacity of the oceans means that temperature changes must be measured with greatprecision and with high resolution, both of which have been difficult to achieve. The majority of the historicalglobal temperature changes come from Expendable Bathythermographs (XBTs) and Conductivity/Temperature/Depth (CTD) shipboard measurements. However, spatial and temporal sparseness of data, regional and temporalbiases in observations, and changing proportions of data from different instrument types, established the needfor a homogeneous global observing system. This need led to the implementation of the international array ofArgo profiling floats. Argo is a global array of 3 000 free-drifting profiling floats that measure the temperature andsalinity of the upper 2 000 m of the ocean (see Map 3.1). Temperature, salinity and velocity of the upper oceanare continuously monitored, and all data is made publicly available within hours after collection. One of Argo'smost important contributions is a major improvement in estimates of OHC (von Schuckmann and Le Traon, 2011;Levitus et al., 2012).The main challenge for Argo is to maintain the global array for the next decades, which requires internationalcommitments to provide and deploy about 800 to 900 floats per year.Additional floats would be needed for more uniform sampling and for expanded coverage of polar regions,marginal seas and the deep ocean below 2 000 m depth.In 2008, the project Euro-Argo started developing a European infrastructure for Argo to the level where Europeanpartners have the capacity to support approximately one quarter of the global array, and to provide an additional50 floats per year for enhanced coverage in the European and marginal seas. The Euro-Argo project includesamong others Germany, France and the United Kingdom, which are the major European contributors to Argo.In 2012, the collaboration around Euro-Argo was formalised in a Research Infrastructure Consortium whichenables Europe to build and sustain its contribution to the global array while providing enhanced coverage in theNorth‐east Atlantic, Mediterranean and Black Seas.Map 3.1 Location of Argo floats in 201260 °N30 °N0 °30 °S60 °S60 °E 120 °E 180 ° 120 °W 60 °W 0 °Source: See http://www.argo.ucsd.edu and http://www.euro-argo.eu/About-us/The-Research-Infrastructure.94 Climate change, impacts and vulnerability in Europe 2012