Product 1 (seasonal) files contain 33 level depths (0-5500). Since the EWG CD contains no readings deeper than 4400 m, the last three depths in the files (4500,5000,5500) are optimally interpolated Levitus Analyzed data alone, included simply for consistency in file format.
Product 2 (monthly) files contain 24 ocean depths (0-1500m), exactly like the corresponding Levitus files.
The annual files contain all 33 ocean depths (the average of the monthly down to 1500m and then of the seasonal for the remaining depths).
For a more visual summary, check out: PHC 2.0 Product Summary.
There are 4 pieces of information in each data file below: [temperature or salinity][time period].[Levitus data used].[PHC version].obj
[temperature or salinity] - 'Temp' or 'Salt'
[time period] - '00'=annual, '01'-'12'=months(jan to dec), '13'=winter, '15'=summer
[Levitus data used] - '98'=Levitus 98 data. All of the fields below were created with Levitus 98 data.
[PHC version] - 'p'=patched version. See the note below.
You also have the option of downloading all the files at once in .tar format by clicking the DOWNLOAD ALL link.
UNIX users can then un-tar these data files by using this command: tar xvf PHC.tar. This will make all the data files available in zipped format. To unzip them, use the gunzip command. (example: gunzip Salt00.98.p.obj.gz)
For those unfamiliar with the NODC format, here is an example FORTRAN program that reads Levitus Analyzed fields (the same format as our PHC product):
Or if you prefer, here's an IDL program that does the same:ReadPHC.pro
For those with finer model grid resolution who want a land-filled data file (no masking -99 values to indicate 1x1 Levitus land values) that is still Levitus formatted, here is a FORTRAN program that fills in missing land values using a poisson solver. The function (extrap.f) is taken directly from the 2MOM2.f program: fill_land.f
NOTE: In January, 2001 we updated PHC 2.0 in order to fix a minor bug in the data set. Details are provided HERE.
(the data will be in .tar format)
We thank you for your interest in our database, which may be cited as:
Steele, M., R. Morley, and W. Ermold, PHC: A global
ocean hydrography with a high quality Arctic Ocean,
J. Climate, 14, 2079-2087, 2001.
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