Summer surface salinity field constructed on a 167x63 grid.
From 34.7 psu (blue) to 39.8 psu (red).
This page provides access to the Mediterranean seasonal climatology reconstructed from a historical hydrological data base. The resulting 3D fields (salinity, temperature and velocity) are stored as 3D matrices, with description of the grid location. A direct access to these fields and a description of the file format are also provided in this page.
If you prefer to load the files manually, please use the
ftp server instead.
If there is any problem with this data set (reading, importing, ...) please contact the MODB support (email@example.com).(up to Table of Contents)
We provide two versions of this seasonal gridded data set (MED2 and MED4). They differ by the data base that has been used to build them. Both data sets are accessible in the last part of this page by clicking on the convenient (MED2 or MED4) button.
The MED2 Gridded Data Set is the result of the application of the VIM analysis method (1) on a historical data bank resulting from the merging of two main files:
The MED4 Gridded Data Set has been computed using the first released MODB data base which differs from the previous one mainly by the addition of the bathythermographs from the U.S. NODC world ocean data bank.
THIS ANALYSIS IS STILL IN PROGRESS. IT SHOULD BE CONSIDERED VERY CAUTIOUSLY MAINLY BECAUSE THE FULL QUALITY CHECK OF THE BANK IS NOT FINISHED YET.
The fields might consequently exhibit some unrealistic patterns. Nevertheless, we think that they contain interesting new features (especially the velocity fields). It is the reason why we decide to make them publicly available.(up to Table of Contents)
There are four seasons for the data set :
- WINTER : January, February, March
- SPRING : April, May, June
- SUMMER : July, August, September
- AUTUMN : October, November, December
There are four files for each season :
- U HORIZONTAL (GEOSTROPHIC) VELOCITY,
- V HORIZONTAL (GEOSTROPHIC) VELOCITY.
Units are 0/00 for salinity, degree Celsius for temperature and m/s for velocity.(up to Table of Contents)
To understand the way the data is stored, please refer to the figure below. The file are stored in a 3D array (matrix) with 3 indexes I, J, K, going from 1 to IMAX, 1 to JMAX, 1 to KMAX. The origin is located at the 'bottom left deepest corner'.
There are KMAX horizontal slices from the bottom (K=1) to the surface (K=KMAX). Increasing I's go from W to E and increasing J's go from S to N.
Islands, coasts and places where there are no values are represented by an exclusion value.(up to Table of Contents)
The point (i,j,k) is located at (-5.5 + i*0.25 , i=1,167) long and (30.0 + j*0.25 , j=1,63) lat at a depth given by the Kth line of the file MED2.zed or MED4.zed .
The data sets are stored in compressed ASCII files. First you must 'uncompress' the files with the Unix command 'uncompress'. The size of your file will increase to about 4.3 MB.
The first line of the ASCII file contains the dimension of the array : IMAX, JMAX, KMAX. The integers are stored with the FORTRAN format I5.
The second line contains the exclusion value, the minimum and the maximum value of this file. These numbers are stored with the FORTRAN format E12.5.
The remaining lines contains the data of the array, with 5 numbers per line (except the last line for each I-line).
The array is stored in horizontal slices from sea surface to sea bottom and from north to south. So the indexes go from :
DO K = KMAX to 1 DO J = JMAX to 1 DO I = 1 to IMAX read OD OD OD
There are two examples of extracting routines written in FORTRAN :
readata1.f , readata2.f
Here is the list of the available matrices :