CSIRO ERA-40 2.5 deg by 2.5 deg archive (Grib & netCDF format ERA-40 datasets)

ERA-40 2.5° by 2.5° reanalysis archive containing primary (4-times daily GRIB) and processed (4-times daily and climatological netCDF)data. The atmospheric model used for ERA-40 has the identifier IFS CY23r4 and is comprehensively documented on the ECMWF website at http://www.ecmwf.int/research/ifsdocs/CY23r4/index.html. It has 60 levels in the vertical, uses a T159 spherical-harmonic representation for the dynamical fields, and a reduced Gaussian grid with an approximately uniform 125 kilometre spacing for surface and other grid-point fields. An essential part of the ERA-40 activity was the production of an archive of data in GRIB format. Parameters such as the 4-times daily surface and pressure level files were processed to produce COARDS conforming netCDF files which are self describing, machine transperant and which employ a similar metacode specification to that in the NCEP re-analysis files. This makes it possible for users of the NCEP/NCAR reanalysis to be able to easily switch data input to ERA-40. Only the 4-times daily GRIB files have been further processed and are on a 2.5 by 2.5 degree horizontal grid (144 by 73 regular grid points) for each of the standard 23 pressure levels (0001, 0002, 0003, 0005, 0007, 0010, 0020, 0030, 0050, 0070, 0100, 0150, 0200, 0250, 0300, 0400, 0500, 0600, 0700, 0775, 0850, 0925 and 1000)