Table of Content

• 1. Introduction
• 2. Analysed Data Fields
• 3. Matrix description
• 4. Localization
• 5. Reading the data
• 6. Access to the Data Fields

1. Introduction

This page provides access to the Mediterranean seasonal climatology reconstructed from a historical hydrological data base. The resulting 3D fields (salinity and temperature) 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.

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2. Analysed Data Fields

This data set corresponds to a monthly climatolgy. It will be reffered to as the MED6 climatology, it is based on the MEDATLAS data bank using the MODB analysis technique.

There are 2 files for each month :

1. SALINITY,
2. TEMPERATURE,

Units are 'psu' for salinity and 'degree Celsius' for temperature.

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3. Matrix description

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.

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4. Localization

The point (i,j,k) is located at (-9.75 + i*0.25 , i=1,184) long and (30.0 + j*0.25 , j=1,63) lat at a depth given by the Kth line of the file MED6.zed ,

Example :

The point (3,4,1) is located at -9 long and 31.0 lat at -5m under the sea surface.

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5. Reading the data

The data sets are stored in compressed ASCII files. First you must 'uncompress' the files with the command 'gzip -d'. The size of your file will increase to about 5 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.gz , readata2.f.gz

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6. Access to the Data Fields

Here is the list of the available matrices :

1. Temperature
   
   JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
   
   
   
2. Salinity
   
   JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
   

You can also download data via ftp from MFSTEP server

ftp data.bo.ingv.it
login: (as known by MFSTEP users)
password: (as known by MFSTEP users)

cd mfstep/MED6_clim/

For login and password ask to Info Products(info.products@bo.ingv.it)

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