A simple naming convention for the ocean files is suggested. Each file should contain a single parameter with all the members for a period of time. This means that slightly different names are required for the analysis and the forecast files. The file name intends to clearly identify the experiment that has generated the data, although this information will be contained in the metadata too.

The analysis files should contain twelve time steps (or less if the first or last year of the analysis does not cover the 12 months). Names should be of the form

OR3_129_MM_2003_EG.nc

where OR3 is for the ECMWF System 3 ocean reanalysis (other names with three characters to be chosen for the analyses prepared by other centres), 129 for the variable number (see list below for the numbers of all the variables required), MM is for monthly means (use II, DD or WW if you ever prepare files with instantaneous, daily mean or weekly mean values), EG for the interpolated (ENSEMBLES) grid (use OG for the original grid) and 2003 for the year in the file.

The seasonal and annual hindcast files should contain all the predictions initialized that year (a maximum of 35 time steps for the Stream 2 data, which is 3 start dates with 7 months and 1 start date with 14 months). The name should be

FC?_129_MM_2003_EG.nc

where the ? stands for the producer, being E for ECMWF, M for Météo-France, G for GloSea, D for DePreSys, C for CERFACS, I for IfM and B for INGV. While each partner will generate their own NetCDF files, the final dataset will consist of files containing multi-model and multi-parameter ensembles. The name of those files will not identify the experiments contained, as this information is already in the metadata. Hence, the names of those files will be of the type FC_129_MM_2003_EG.nc.

The decadal hindcast files should contain the data of a predicted year initialized on a specific year. The file name should be

FC?_129_MM_1965_1970_EG.nc

where the ? has the same meaning as in the previos paragraph, 1965 is the year of the start date of a particular hindcast and 1970 is the verifying year of the data. This means that the first file of the hindcast started on the first of November 1965 (FC?_129_MM_1965_1965_EG.nc) will contain the monthly means for November and December 1965, the second file (FC?_129_MM_1965_1966_EG.nc) will have the data for the 12 months from January to December 1966 and so on.

All these files can be manipulated with NCO to create files to obtain the files with the structure requested. NCO can be used to concatenate files from different start dates or to modify the dimensions and coordinate variables. Unfortunately, these functions are greedy with the memory. Do not hesitate to contact us for help with their use.

The list of parameter numbers (3 digits) is:

129: temperature
130: salinity
131: zonal velocity
132: meridional velocity
133: vertical velocity
145: sea level
148: mixed layer depth
163: D20
164: average potential temperature in the upper 300m
175: average salinity in the upper 300m
140: UV
141: UT
142: VT
143: UU
144: VV

23.01.2008