The European Centre for Medium-Range Weather Forecasts (ECMWF) has provided global atmospheric analyses from its archive for many years. The ERA-15 Re-analysis project was devised in response to wishes expressed by many users for a data set generated by a modern, consistent, and invariant data assimilation system. The ERA-15 project produced a long time-series (January 1979 - February 1994) of consistent meteorological analyses using a single version of the ECMWF model.

This dataset contains surface orography data. These data are available in gaussian N80 gridded, lat-long (2.5 degree) gridded and spectral form, from the initialised and uninitialised datasets (N.B. initialised spectral is missing at the moment).

Note that the grid-point orography files change with date. This does not affect the ERA period but if you use Operational data for later dates you will need

to use the different orography files from our ecmwf-op directory.

The spectral orography file spor90010100 contains just the orography data (surface geopotential).

The other files contain the constant fields:

Geopotential (at the surface, orography)

Standard deviation of orography

Anisotropy of subgrid scale orography

Angle of subgrid scale orography

Slope of subgrid scale orography

Land/Sea mask

gpor79010100 contains the gaussian gridded data

llor80010100 contains the 2.5 degree gridded data