slev225.dat file can be read with the following fortran program:

!------------------------------------------------------------------------------
      program read_slev
!     -----------------

      implicit none

      character*3 code
      character*8 station
      character*14 latitude,longitude
      character*256 line
      integer index
      integer year,month,day,i,height(12)
      logical loop

      open(10,file='slev225.dat',status='old')
      loop=.true.
      do while (loop)
         read(10,'(a)',end=1000) line

! head line
         if (index(line,'LAT').ne.0) then
            read(line,1010) code,station,year,latitude,longitude
            write(*,1010) code,station,year,latitude,longitude
            read(10,'(a)',end=1000) line
         endif

! data line
! for i=1, 1st value corresponds to 00h, 2nd to 01h, ..., 12th to 11h
! for i=2, 1st value corresponds to 12h, 2nd to 13h, ..., 12th to 23h
         read(line,1020,end=1000) code,station,year,month,day,i,height
         write(*,1020) code,station,year,month,day,i,height
      enddo

 1000 close(10)
 1010 format(a3,a8,i4,2x,2a14)
 1020 format(a3,a8,i4,2i2,i1,12i5)
      end
!------------------------------------------------------------------------------

slev225.dat is for sea level hourly data, height in millimeter, undefined value is 9999.

baro225.dat, bot225.dat, fbot225.dat, fslev225.dat and twat225.dat files can be read with the following fortran program:

!------------------------------------------------------------------------------
      program read_baro
!     -----------------

      implicit none

      character*3 code
      character*8 station
      character*14 latitude,longitude
      character*256 line
      integer index
      integer year,month,day,i,value(12)
      logical loop

      open(10,file='baro225.dat',status='old')
      loop=.true.
      do while (loop)
         read(10,'(a)',end=1000) line

! head line
         if (index(line,'LAT').ne.0) then
            read(line,1010) code,station,year,latitude,longitude
            write(*,1010) code,station,year,latitude,longitude
            read(10,'(a)',end=1000) line
         endif

! data line
! for i=1, 1st value corresponds to 00h, 2nd to 01h, ..., 12th to 11h
! for i=2, 1st value corresponds to 12h, 2nd to 13h, ..., 12th to 23h
         read(line,1020,end=1000) code,station,year,month,day,i,value
         write(*,1020) code,station,year,month,day,i,value
      enddo

 1000 close(10)
 1010 format(a3,a8,i4,2x,2a14)
 1020 format(a3,a8,i4,2i2,i1,12i6)
      end
!------------------------------------------------------------------------------

baro225.dat is for barometric pressure hourly data.
bot225.dat is for bottom pressure hourly data.
fbot225.dat is for bottom pressure hourly data filtered with a 3-days Demerliac filter.
fslev225.dat is for sea level hourly data filtered with a 3-days Demerliac filter.
twat225.dat is for water temperature hourly data.
Barometric pressure, bottom pressure and filtered bottom pressure in hPa times 10.
Filtered sea level in millimeter.
Water temperature in degree Celsius times 10.
Undefined value is 99999.

Sea level, barometric pressure, bottom pressure and water temperature data are real time data.

The Sao Tome tide gauge station automatically acquires hourly measurements of seawater bottom pressure (Pb), temperature and conductivity together with atmospheric pressure (Pa) triggered at the same time.
The tide gauge station builds an Argos message containing the measurements from the last 7 hours and sends out the message every 200 seconds. This message is recovered by satellite via the Argos system and is transmitted to the CLS processing center in Toulouse, France.
The message is then automatically sent to a dedicated email address at the LEGOS laboratory in Toulouse.
The received Argos message automatically activates a software. The software decodes the telemetry contained in the Argos message and computes the data.
From the measurements simultaneously acquired by the tide gauge station, the seawater salinity and density are computed using the UNESCO algorithms. Then the sea level is computed from the atmospheric pressure, seawater bottom pressure, density (rho) and gravity (g):
height = ( Pb - Pa ) / ( rho * g )

Sao Tome station has been installed by IRD (ex ORSTOM).

Sao Tome tide gauge station consists of a MarArgos 200 central unit which activates an Aanderaa WLR7 tide recorder (seawater bottom pressure, temperature and conductivity measured) and an Orion barometer (atmospheric pressure measured) at the same time than the bottom pressure, sampled every hour.
The sea level is computed with seawater salinity supposed as a constant and equal to 35 PSS.
From june 1999 to 17th september 2000 the ORION barometer is not temperature compensed. From 18th september 2000 the barometric pressure data seem correct.
From 15th february 2001 a new tide recorder has been installed 49 cm lower than before. From this day a correction of 49 cm has been applied to sea level to have continuous data.
From 27th august 2004, the tide recorder has been moved. It is now installed along the wharf of Sao Tome.

baro225.ps corresponds to plot of barometric pressure as a function of time.
bot225.ps corresponds to plot of bottom pressure as a function of time.
fbot225.ps corresponds to plot of filtered bottom pressure as a function of time.
slev225.ps corresponds to plot of sea level as a function of time.
fslev225.ps corresponds to plot of filtered sea level as a function of time.
twat225.ps corresponds to plot of water temperature as a function of time.

Sao Tome data are available from the LEGOS anonymous ftp site:
http://www.legos.obs-mip.fr/en/soa/rosame/donnees/

Real time monitoring of the Sao Tome coastal tide gauge is available from the LEGOS web site:
http://www.legos.obs-mip.fr/en/rosame/

Updated on 18 Sep. 2008