The Drakkar Forcing Set 5.2 has been developed to drive ocean hindcasts of the period 1958 to 2015 (see also Table 1). It includes the following surface variables required by the NEMO bulk formula to calculate heat, freshwater and momentum fluxes across the air-sea interface (i.e. the surface boundary condition to the model primitive equations).

* zonal and meridional components of the 10-m wind : u10, v10

* 2-m air humidity : q2

* 2-m air temperature : t2

* downward shortwave radiation at the sea surface : radsw

* downward longwave radiation at the sea surface : radlw

* precipitation total and solid : P, snow

The DFS5.2 data set has been built to take advantage of ERA-interim, the most recent atmospheric reanalysis produced at ECMWF (Dee et al., 2011). ERAi provides the surface atmospheric variables required to drive global ocean hindcasts simulations for the period 1979-2015. Compared to previous reanalyses, it has the advantage of an increased spatial resolution (~0.7°) and denser time sampling (3 hours) that resolves the diurnal cycle. However, ERAi is limited to the period 1979-2015, and has to be combined to another data set, e.g. ERA40 which does include the period 1958-1978. DFS5.2 has been constructed following a step by step methodology. (see https://www.drakkar-ocean.eu/forcing-the-ocean).