General information: The meteorological data set covers the whole Baltic drainage basin with a grid of (1×1)º squares. The grid extends over the area: Latitude N 49.5º - 71.5º, Longitude E 7.5º - 39.5º. The present available time period is from 1970 to 2002.

Method: Data from all available synoptic weather stations were used. The parameters were interpolated in space using a two-dimensional univariate optimum interpolation scheme. The degree of spatial filtering of optimum interpolation is determined by an isotropic autocorrelation function, and this function was estimated from the database. A quality control algorithm to reject erroneous observations was built into the objective analysis scheme. The data set was established by and is maintained by Lars Meuller at SMHI.

Time resolution: UTC 00, 03, 06, 09, 12, 15, 18, 21
(for the period 19700101 -- 19770831 only 00, 06, 12, 18)

Parameters:

Please note that Global radiation is a computed parameter, see 'Computed Global Radiation using Interpolated, Gridded Cloudiness from the Meso-Beta Analysis compared to Measured Global Radiation'; Josefsson, W.; SMHI METEOROLOGI; Report No.101; 1989)

File format: There are two available formats.

• The meteorological data can be distributed in zipped ASCII-files, one zip-file for every month in the period. These zip-files contain up to 248 ASCII-files, one for every 3 hours in the month. In the separate ASCII-files, the 'squares' are sorted in rows from southwest corner to northeast corner of the grid. The first row represent the square in the southwest corner of the grid. The second row represent the next square east of the first, and so on. The last row represent the square in the northeast corner of the grid. An example of this file format 1980010100.txt (0.5kb). This ASCII-file has been cut down to show the parameters of the first four squares and the last square.

• The meteorological data could also be distributed in GRIB-format, defined in WMO no.306 Manual on Codes, Volume 1 International Codes, Part B Binary Codes. This is the format used in the SMHI Field Data Base.

N.B.: Values for Total precipitation are missing for the following 20 files: 1979020318, 1979041806, 1979112118, 1980111218, 1980121618, 1981041218, 1982011006, 1982011018, 1982011806, 1986041306, 1990100418, 1991080306, 1992063018, 1992102718, 1992110118, 1995120518, 1996012706, 1996042318, 1996060406, 1996102706.