About GTSPP Best Copy Data Sets

The GTSPP Long-Term Archive, operated by US NODC, holds, in the beginning, the real-time data from ISDM received three times per week. Delayed mode data include the full resolution data from XBTs or CTDs from the ships, or fully processed and quality controlled data from the organizations that provided the real time low resolution data to the GTS. If a low resolution real time copy of the data are already in the CMD the better quality or higher resolution copy replaces the real time one as the best copy. The best copy data files are assembled to provide the most complete data sets without duplication and comprise the best temperature and salinity stations for each month for which data is available in the data base, from either real-time (BATHY or TESAC) data, or delayed mode, full resolution profiles of (PI-submitted) XBT and CTD data. Where matching stations are found, the delayed mode, full resolution profile is included and the real-time, lower resolution profile is excluded, to make it the "best copy" available.

The Best Copy data (individual station) files are split into three oceans and months of years. All of the stations for a month are compressed into one single file. Each month also has its own index file (inventory table) that lists the path and the file names of all files, using the following folder hierarchy.

• HTTP: http://data.nodc.noaa.gov/gtspp/
• FTP: ftp://ftp.nodc.noaa.gov/pub/data.nodc/gtspp/
• THREDDS: http://data.nodc.noaa.gov/thredds/catalog/gtspp/catalog.html

The data are organized as a small set of directory hierarchies. The top level of the directory tree contains a README file and two plain text files, gtspp_add.txt and gtspp_rmd.txt, showing the GTSPP database identification numbers and names of the individual files are being added or removed, respectively.

The sub-trees are:

1. atlantic/
2. best/
3. best_inv/
4. best_nc/
5. indian/
6. pacific/

The following sessions descript the detail information about these sub-directories:

atlantic/ This directory contains individual profile (stations) netCDF files for observations in the Atlantic ocean from 1990 to present.

best/ The "best" directory contains the GTSPP best copy data sets in the MEDS ASCII format. The MEDS ASCII datasets are split into three oceans, and are assembled as months of years and compressed, using the unix utility "gzip". The file naming convention is OOYYYYMM.gz, where OO is a two-character ocean code (at=atlantic, in=indian, and pa=pacific), YYYY is a four-digit Year, MM is the two-digit Month of the year, and ".gz", is a special extension for files compressed using the "gzip" unix utility.

best_inv/ The "best_inv" directory contains inventory files for each monthly archive. Each file lists the call sign of platforms, the path and the file names of netCDF files, the stations with observations in that month giving the sampling date (year, month, and day), location (latitude and longitude, negative numbers are for southern latitudes and western longitudes), and data min/maxes. Fields with missing min/maxes indicate the data quality is probably bad or bad.

best_nc/ The "best_nc" directory contains the GTSPP best copy data with only TEMP and PSAL data records stored in the netCDF format. The GTSPP netCDF datasets are split into three oceans, and are assembled as months of years and compressed, using the unix utility "zip". The file naming convention is "gtspp4_OOYYYYMM.zip", where OO is a two-character ocean code (at=atlantic, in=indian, and pa=pacific), YYYY is a four-digit Year, MM is the two-digit Month of the year, and ".zip", is a special extension for files compressed using the "zip" unix utility. indian/ This directory contains individual profile (stations) netCDF files for observations in the Indian ocean from 1990 to present.

indian/ This directory contains individual profile (stations) netCDF files for observations in the Indian ocean from 1990 to present

pacific/ This directory contains individual profile (stations) netCDF files for observations in the Pacific ocean from 1990 to present.