The Pacific Ocean analysis is from an ocean-data assimilation system
(ODAS) developed at the Coupled Model Project/NMC. The ODAS inserts
ocean-temperature observations into a GCM of the tropical Pacific Ocean
in order to approximate three-dimensional fields of ocean temperature.
Because ocean currents are driven on density variations which are
largely a result of temperature variations the currents are also
approximated by the ODAS.  The idea behind the ODAS is the same idea
behind atmospheric analysis that has been done at NMC for a number of
years.  Data used in the ODAS includes XBT observations, and SST from
satellites, ships, and buoys.  The ODAS has remained unchanged since
Jan 1991.

Published references:

Leetmaa, A. and M. Ji, 1989: Operational hindcasting of the tropical Pacific.
  Dyn. Atmos. Oceans, 13, 465-490.

Derber, J. and A. Rosati, 1989: A Global Oceanic Data Assimilation System.
  J. Phys. Oceanogr., 19, 1333-1347.



GRID AND DATA FILE DESCRIPTION
The grid dimensions for temperature and velocity (u and v components)
are 81x112x27 (latitude x longitude x depth).  The grid point
separation is 1 degree in the latitude, 1.5 degrees in longitude , and
at selected levels in depth.  The temperature grid spans 35.5S - 44.5N
and 122.25E - 288.75E while the velocity components are offset and
align with 35.00S - 45.0N and 123.0E - 289.5E . Tables illustrating the
3-Dimensional grid are shown below.  The data are stored as IEEE 32 bit
floating point binary real numbers.  Each weekly grid set is preceeded
with a header that identifies the year, month and the end day of the
run for each grid.  Following the header, longitude x depth sections
for u,v and t are sequentially stored beginning at the southern most
latitude and stepping northward.  Realistic land an bottom topography
is determined by 0.0 in the temperature grids or by using a land/sea
mask.  A simple fortran program is given below that will read the
data.

     Temperature is in units of degrees C and u and v are in cm/s.



CODE TO READ THE DATA AND GENERATE AND SAMPLE PRINT-OUT :

      Program
      dimension dummy(710),spc(5),u(112,27),v(112,27),t(112,27)

      open(10,file='subsfc.uvt.1992.sep',
     1form='unformatted',status='old')

  10  read(10,end=99) dummy,spc
      iyr=spc(2)
      imo=spc(3)
      idy=spc(4)

c     print * , iyr,imo,idy

      write(*,'(/)')
      write(*,*) ' YR = ',iyr,' MO = ',imo,' END DAY = ', idy

      do 200 j=1,81
	 read(10) ((u(i,k),i=1,112),k=1,27),
     1            ((v(i,k),i=1,112),k=1,27),
     2            ((t(i,k),i=1,112),k=1,27)
       write(*,'(i3,3(a4,3f7.2))') j,' U: ',u(1,1),u(56,14),u(112,27),
     1' V: ',v(1,1),v(56,14),v(112,27),' T: ',t(1,1),t(56,14),t(112,27)

  200 continue
      go to 10

  99  continue
      end


	LONGITUDE                                LATITUDE
grid   Temp           u,v                grid   Temp           u,v
  1   122.25        123.00                 1    -35.50       -35.00
  2   123.75        124.50                 2    -34.50       -34.00
  3   125.25        126.00                 3    -33.50       -33.00
  .                                        .
  .                                        .
111   287.25        288.00                80     43.50        44.00
112   288.75        289.50                81     44.50        45.00



    DEPTH LEVELS
  LEVEL    DEPTH (METERS)                 LEVEL  DEPTH (METERS)
    1          5.00                        15        177.50
    2         15.00                        16        205.00
    3         25.00                        17        240.00
    4         35.00                        18        288.50
    5         45.00                        19        362.50
    6         55.00                        20        483.50
    7         65.00                        21        680.00
    8         75.00                        22        979.50
    9         85.00                        23       1395.50
   10         95.00                        24       1916.00
   11        106.25                        25       2524.00
   12        120.00                        26       3174.00
   13        136.25                        27       3824.00
   14        155.00

   Bottom = 4149m.