DESCRIPTION: Time series of monthly averages by variable derived from GODAS operational datasets.
SOURCE: NCEP Global Ocean Data Assimilation System
NOTE:
"Corrected" GODAS analyses were made available on February 6, 2006.
The files below are derived from the corrected analyses. The GODAS WWW states:
The correction involves analyses only through the end of 1989.
Nevertheless, the new analyses were extended through 2004 and
the post-1990 analyses will show small differences with the earlier
version due to small changes to the assimilation data set.
AVAILABILITY: All data are available from the NCAR Mass Storage System (MSS).
FORMAT: netCDF
The netCDF version was produced by the Climate Analysis Section
as a community service.
The contents conform to the netCDF
Climate and Forecast (CF) Metadata Convention .
The purpose is to facilitate evaluation of the CCSM and to produce datasets that
may be more readily
analyzed by commonly available software tools.
Each file was converted from the original GRIB format to netCDF
using NCL (NCAR Command Language).
The netCDF operators
were used to extract each variable and create a time series.
GRID: Rectangular Grid (unequally spaced)
TIMES: Monthly Means
DATES: January 1980 - December 2005
LEVELS:
40 levels (m):
5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155,
165, 175, 185, 195, 205, 215, 225, 238, 262, 303, 366, 459, 584, 747, 949,1193,
1479,1807,2174, 2579,3016,3483,3972,4478
FIELDS:
netCDF number
Description Name units levels
------------------------------------------------------------------
Total downward heat flux at surface THFLX W/m2 1
Salt Flux SLTFL g/cm2/s 1
Sea Surface Height Relative to Geoid SSHG m 1
Geometric Depth Below Sea Surface DBSS_OBIL m 1 level indicator=238
Geometric Depth Below Sea Surface DBSS_OBML m 1 level indicator=237
Momentum flux, u component U_FLX N/m^2 1
Momentum flux, v component V_FLX N/m^2 1
Salinity SALTY kg/kg 40
u-component of current UOGRD m/s 40
v-component of current VOGRD m/s 40
Geometric vertical velocity DZDT m/s 40
Potential temperature POT K 40
Potential temperature is defined as the temperature of a parcel of water
at the sea surface after it has been raised adiabatically from some depth in the ocean.
MSS PATH:
/CA/GODAS/
MSS FILE NAMES:
The MSS file names are of the form vName.yearStart-yearLast.nc
where yearStart and yearLast are the years included on the file and vName is the netCDF variable name (above).For example:
POT.1980-1984.nc
POT.1985-1989.nc
POT.1990-1994.nc
POT.1995-1999.nc
POT.2000-2005.nc [note extra year]
MSS FILE SIZE:
Each 5-year file for a single level variable is 18 MB. Each 5-year file for a 40-level variable is 722 MB. The 6-year files are 21MB and 855MB, respectively.
REFERENCES
See bottom of http://www.cpc.ncep.noaa.gov/products/GODAS/background.shtml
netCDF metadata:
Most of the meta data associated with each variable may be ignored.
It was created by NCL as part of the process of converting GRIB to netCDF.
netcdf POT.1995-1999 {
dimensions:
time = UNLIMITED ; // (60 currently)
depth = 40 ;
tlat = 418 ;
tlon = 360 ;
variables:
int depth(depth) ;
depth:positive = "down" ;
depth:units = "m" ;
depth:long_name = "depth below sea level" ;
float tlon(tlon) ;
tlon:La1 = -74.5f ;
tlon:Lo1 = 0.5f ;
tlon:La2 = 64.499f ;
tlon:Lo2 = 359.5f ;
tlon:Di = 1.f ;
tlon:Dj = 0.3333309f ;
tlon:units = "degrees_east" ;
tlon:GridType = "Cylindrical Equidistant Projection Grid" ;
tlon:long_name = "longitude" ;
float tlat(tlat) ;
tlat:La1 = -74.5f ;
tlat:Lo1 = 0.5f ;
tlat:La2 = 64.499f ;
tlat:Lo2 = 359.5f ;
tlat:Di = 1.f ;
tlat:Dj = 0.3333309f ;
tlat:units = "degrees_north" ;
tlat:GridType = "Cylindrical Equidistant Projection Grid" ;
tlat:long_name = "latitude" ;
double time(time) ;
time:units = "hours since 1901-01-01 00:00:0.0" ;
time:info = "This is the LAST day of the averaging period. Consistent with original GRIB." ;
time:long_name = "time" ;
int date(time) ;
date:units = "YYYYMM" ;
float timePlot(time) ;
timePlot:info = "good for plotting time series" ;
timePlot:units = "YYYY.(fractional part of year)" ;
short POT(time, depth, tlat, tlon) ;
POT:_FillValue = 32767s ;
POT:sub_center = "Environmental Modeling Center" ;
POT:center = "US National Weather Service - NCEP (WMC)" ;
POT:long_name = "Potential temperature" ;
POT:units = "K" ;
POT:level_indicator = 160 ;
POT:gds_grid_type = 0 ;
POT:parameter_table_version = 2 ;
POT:parameter_number = 13 ;
POT:add_offset = 285.f ;
POT:scale_factor = 0.001525925f ;
POT:vMin_user_specified = 260.f ;
POT:vMax_user_specified = 310.f ;
POT:vRange = 50.f ;
// global attributes:
:creation_date = "Wed Dec 14 14:23:51 MST 2005" ;
:sfcHeatFlux = "\n",
"Note that the net surface heat flux are the total surface heat flux \n",
"from the NCEP reanalysis 2 plus the relaxation terms." ;
:time_comment = "\n",
"To maintain consistency with NCEP: \n",
"The internal time stamp indicates the LAST day of the averaging period." ;
:caveat = "\n",
"There is a warm bias in GODAS before the early 1990s. \n",
"The GODAS uses 1992 as a start date for their climatology, \n",
"so 1992 onward may be best." ;
:NCL_Version = "4.2.0.a033" ;
:NCL = "modified ncl_grib2nc: grib2nc_GODAS.ncl_short" ;
:system = "IRIX64 tempest 6.5 07080049 IP35" ;
:conventions = "None" ;
:grib_file = "godas.M.200001.grb" ;
:html_REFERENCES = "http://www.cpc.ncep.noaa.gov/products/GODAS/background.shtml" ;
:html_BACKGROUND = "http://www.cpc.ncep.noaa.gov/products/GODAS/background.shtml" ;
:html_GODAS = "www.cpc.ncep.noaa.gov/products/GODAS" ;
:title = "GODAS: Global Ocean Data Assimilation System" ;
:history = "Wed Dec 14 15:40:45 2005: ncrcat -v POT godas.M.200001.SHORT.nc godas.M.200002.SHORT.nc
godas.M.200003.SHORT.nc godas.M.200004.SHORT.nc godas.M.200005.SHORT.nc
[SNIP]
godas.M.200408.SHORT.nc godas.M.200409.SHORT.nc godas.M.200410.SHORT.nc godas.M.200411.SHORT.nc godas.M.200412.SHORT.nc POT.
2000-2004.nc" ;
:nco_openmp_thread_number = 1 ;
}
(END)
Back to the CAS Data Catalog
Back to the CAS Home PageDennis Shea: shea@ucar.edu