Données en accès public

Citations:

Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer P, Bechtold P, Beljaars ACM, van de Berg L, Bidlot J, Bormann N, Delsol C, Dragani R, Fuentes M, Geer AJ, Haimberger L, Healy SB, Hersbach H, Ho ́lm EV, Isaksen L, Ka ̊llberg P, Ko ̈hler M, Matricardi M, McNally AP, Monge-Sanz BM, Morcrette J-J, Park B-K, Peubey C, de Rosnay P, Tavolato C, The ́paut J-N, Vitart F. 2011. The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137: 553–597. DOI:10.1002/qj.828

The ERA-Interim project was initiated in 2006 to provide a bridge between ECMWF’s previous reanalysis, ERA-40 (1957-2002), and the next-generation extended reanalysis envisaged at ECMWF. The main objectives of the project were to improve on certain key aspects of ERA-40, such as the representation of the hydrological cycle, the quality of the stratospheric circulation, and the handling of biases and changes in the observing system. These objectives have been largely achieved as a result of a combination of factors, including many model improvements, the use of 4-dimensional variational analysis, a revised humidity analysis, the use of variational bias correction for satellite data, and other improvements in data handling.

The ERA-Interim atmospheric model and reanalysis system uses cycle 31r2 of ECMWF’s Integrated Forecast System (IFS), which was introduced operationally in September 2006, configured for the following spatial resolution:

• 60 levels in the vertical, with the top level at 0.1 hPa;

• T255 spherical-harmonic representation for the basic dynamical fields;

• a reduced Gaussian grid with approximately uniform 79 km spacing for surface and other grid-point fields.

The atmospheric model is coupled to an ocean-wave model resolving 30 wave frequencies and 24 wave directions at the nodes of its reduced 1.0ox1.0o latitude/longitude grid.