
3D T/S, geostrophic horizontal and quasigeostrophic vertical velocity fields
1. IntroductionThis page provides access to the T/S, horizontal geostrophic velocity fields and quasigeostrophic vertical velocity fields reconstructed from the omega BIOhesperides cruise. The resulting 3D analysed fields (temperature, salinity and velocity) are stored as 3D matrices. (up to Table of Contents)2. Analysed Data FieldsThere are three consecutive survey from the BIO Hesperides Cruise:
The T,S fields were computed by a variational inverse method and calibrated by a crossvalidation procedure. The geostrophic velocities were obtained by integrating the thermal wind equation with a reference level of 200m, and adding a nondivergent stream function computed from ADCP data at that level. The vertical velocities were computed from the quasigeostrophic omega formulation. Units are 'psu' for salinity, 'degree Celsius' for temperature and 'm/s' for horizontal geostrophic velocity. Vertical velocity unit is m/day. To get pseudosynoptic analysed fields, several methods have been developped and implemented
3. Format descriptionTo 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. The point (i,j,k) is located at (5.0 + i*0.03 , i=0,43) long , (35.7 + j*0.025 , j=0,28) lat and (301+k*8, k=0,37) m depth except for vertical velocities where point (i,j,k) is located at (4.94 + i*0.03 , i=0,39) long , (35.75 + j*0.025 , j=0,24) lat and (301+k*8, k=0,37) m depth. Extracting routine written in FORTRAN : C  SUBROUTINE READIT (A,IMAX,JMAX,KMAX) C  REAL*4 A(IMAX,JMAX,KMAX) INTEGER IMAX,JMAX,KMAX DO 10 K = 1,KMAX DO 20 J = 1,JMAX READ (10,101) (A(I,J,K),I=1,IMAX) 20 CONTINUE 10 CONTINUE 101 FORMAT (5E12.5) END(up to Table of Contents) 4. Access to the 3D analysed fieldsTo download the files, put a '.Z' after the file name. Uncompress the files with 'uncompress < filename >'.
5. Access to the jpg images
Last modified October 26, 1998 Send comments to M.Rixen@ulg.ac.be 