ERA40 is the computerized weather data from September 1957 to August 2002 (i.e. during 45 years), taken from scientific relevant observations worldwide. The data has been worked out by the European Centre for Medium-Range Weather Forecasts (ECMWF).

As the follow-up project ERA Interim provides data fom 1989 on until present.

Contracted by the DWD, "Model & Data" is the German distributor of these data.

In general, the ERA data is open for scientific use to registered users only. For all other purposes, please contact the DWD. See below for registration (Chapter "How to get the data?").

The data are grouped in several ways:

• by temporal resolution:
  the computer model used to assimilate the observational data is restarted every 6 hours (00:00, 06:00, 12:00, 18:00 UTC). ERA40 data is stored four times a (model) day. Additionally, monthly means of each of the four times separately are available, as well as the total monthly mean of all data of a certain parameter.
• by spatial resolution:
  we only offer the spatial resolution of Gaussian Grid "N80" (sometimes called "TL159"). For atmospheric fields as model levels, the parameters 130, 135, 138, and 155 are offered on the corresponding spherical harmonic grid, which for ERA40 is T159.
  The ECMWF also offers more coarse ERA40 data (2.5°) and data from their wave model.
• by level type:
  ground data have only level "surface" (sfc), upper air fields can be retrieved on 60 different model levels or on 23 different pressure levels.
• by forecast step:
  forecasts have been calculated for 3, 6, 12, ... 36 hours step width. Step width 00 corresponds to pure analysis, i.e., no forecast. At Model & Data we offer the 00 and 06 hours step. Very few data of step 03 is avalable, too.
• by physical parameter:
  the data is available for many physical parameters, mostly identified by their numbers as listed in table 128 at ECMWF (see linklist at top of this page).

mind:

• For other numbers of forecast steps and parameter codes, please contact data(at)dkrz.de
• some of these data is available via ftp from schauer.dkrz.de, but is not yet filled into the CERA DB.

Find out, what types of data you need: start and end time, time resolution, forecast step, level (surface only, pressure levels, model levevls) and physical parameters.

Fill in the "ecrana form" (found here) to confirm the agreement on data usage and fax +49-40-460094-106 or send it to Model & Data.

Finally, apply for an ERA40 user account at data(at)dkrz.de.

Links to more detailed information at ECMWF:

• The ERA40 Project Report Series
• Technical information: grids, levels, model ids
• The parameters and their units (see standard table no 128)
• The ERA news page

More coarse data is available from the Public Data Server of the ECMWF on a 2.5° x 2.5° grid.

SOFTWARE is available via the CDO and PINGOs' home pages.

	e40Overview.pdf An ERA40 Overview
	e40Project.pdf ERA40 Project Report: Project
	e40Archive.pdf ERA40 Project Report: Archive
	e40Numerics.pdf ERA40 Project Report: Numerics

On the following page you find some technical information on the ERA40 data.