SeaDataNet NetCDF format, MyOcean contribution

NetCDF data file examples

Vertical profile in-situ observations

The following example contains 2 vertical profiles from Pheidippides glider.
Each profile contains pressure, temperature, salinity and oxygen observations.

• MyOcean - SDN vertical profiles sample file, Pheidippides glider, v0.2 27.16 kB
• MyOcean - SDN vertical profiles sample file, Pheidippides glider, ncdump ascii, v0.2 46.88 kB

Trajectory in-situ observations

The following example contains one day of thermosalinograph data from Thalassa research vessel.
Each observation contains temperature, salinity, conductivty and tsg tank temperature.
The depth is reported as 5 meters.

• MyOcean - SDN trajectory sample file, Thalassa thermosalinograph, v0.1 31.56 kB
• MyOcean - SDN trajectory sample file, Thalassa thermosalinograph, ncdump ascii, v0.1 48.68 kB

Time-series in-situ observations

The following example contains one month of observations from CIS-1 mooring (Central Irminger Sea).
There are 15 profiles of 12 levels having temperature, salinity, conductivity and pressure measurements.

• MyOcean - SDN time-series sample file, CIS-1 mooring site, v0.1 16.07 kB
• MyOcean - SDN time-series sample file, CIS-1 mooring site, ncdump ascii, v0.1 22.75 kB

Important features for in-situ data

Vertical axes management

Here are the essential features used by MyOcean and OceanSITES to manage vertical profiles.

Four dimensions

• time = unlimited
• depth = 100

Four axes

• double time(time)
  time:axis = "T" ;
• float depth(depth)
  depth:axis = "Z" ;
• float latitude(time)
  latitude:axis = "Y"
• float longitude(time)
  latitude:axis = "X"

Many variables

• float DataVariable(time, depth)
  coordinates = "time depth latitude longitude";

Links between variables and their associated QC

The variable attribute ancillary_variables links a variable to its associated QC.

• TIME:ancillary_variables = "TIME_QC" ;
  LATITUDE:ancillary_variables = "POSITION_QC" ;
  LONGITUDE:ancillary_variables = "POSITION_QC" ;
  PRES:ancillary_variables = "PRES_QC" ;
  DOX1:ancillary_variables = "DOX1_QC" ;
  PSAL:ancillary_variables = "PSAL_QC" ;
  TEMP:ancillary_variables = "TEMP_QC" ;

Global attributes

Different features

Dimensions for a single profile file with 100 levels:

• featureType = profile
  (time, depth, latitude, longitude) = (1, 100, 1, 1)

Dimensions for a series of 5 profiles with 100 levels

featureType = trajectoryProfile
(time, depth, latitude, longitude) = (5, 100, 5, 5)

Vertical references

Vertical references globale attributes for a glider profiling between 2 and 1002 decibars.

• :geospatial_vertical_min = "2" ;
  :geospatial_vertical_max = "1002" ;
  :geospatial_vertical_positive = "down" ;