A technical description of data format and content.
Version 2.1
Distributed data processing levels for version 2.1 are the daily trajectory summary (l2p) and weekly/monthly gridded data (l3c). The content of products based on the near-real time and reprocessed input version are identical and marked by the timeliness tag in the filename and global attributes of the netCDF files.
l2p trajectory
The Level-2 pre-processed (l2p) product contains daily information from CryoSat-2 at full resolution (see documentation).
Filenaming
The filename of l2p data indicated the timelines (nrt or ntc) and the date (e.g. 20181001) of the data file:
awi-siral-l2p-sithick-cryosat2-{timeliness}-nh-{year}{month}{day}-fv2p1.nc
netCDF Global Attributes
The global attributes of the netCDF file provide metadata such as citation, reference, time coverage and more. Use ncinfo filename.nc
or tools like panoply to list the global attributes.
netCDF Variables
Parameter | Description | Unit | Comment |
---|---|---|---|
freeboard | freeboard of the sea ice layer | meter | |
freeboard_uncertainty | freeboard uncertainty | meter | |
latitude | latitude of satellite nadir measurement point | degrees north | |
longitude | longitude of satellite nadir measurement point | degrees east | |
radar_freeboard | elevation of retracked point above instantaneous sea surface height | meter | radar freeboard is defined as the elevation based |
radar_freeboard_uncertainty | algorithm uncertainty (error propagation) of the radar freeeboard retrieval | meter | |
radar_mode | radar mode flag | None | flag meaning: 0: pulse limited (lrm) |
region_code | Region code (adapted from NSIDC region mask with Baltic Sea added) | None | New in version 2.1 flag meaning: 0: Inland sea and lakes |
sea_ice_density | density of the sea ice layer | kg m-3 | |
sea_ice_density_uncertainty | uncertainty of the sea ice layer density | kg m-3 | |
sea_ice_thickness | thickness of the sea ice layer | meter | |
sea_ice_thickness_uncertainty | uncertainty of the sea ice layer thickness | meter | |
sea_ice_type | fraction of multi-year ice | None | Meaning: 0: only first year ice |
sea_ice_type_uncertainty | uncertainty of sea ice classification | None | |
snow_density | density of the snow layer | kg m-3 | |
snow_density_uncertainty | uncertainty of the snow layer density | kg m-3 | |
snow_depth | thickness of the snow layer | meter | |
snow_depth_uncertainty | uncertainty of the snow layer thickness | meter | |
time | UTC timestamp | seconds since 1970-01-01 |