GoldAltimetry: Along-track and gridded model sea surface height fields for observing system simulation experiments

GoldAltimetry contains two files for use in observing system simulation experiments, or OSSEs, of mapping algorithms involving Jason-class along-track satellite altimetry.   Both of these are based on the GoldOceanNT simulation, a yearlong global ocean experiment without tidal forcing.  Because tides do not appear explicitly in along-track data, having been removed by upstream processing, the no-tides experiment serves as a useful framework for mimicing observed altimeter variability.

The first file, GoldAlongTrack.nc, contains one year of the GoldOceanNT experiment sampled in the same way as the Jason-class satellite altimetry, with one cycle every 9.92 days or 36 cycles over the whole year.  The file format and sampling points are identical to those in the JasonAlongTrack reformatted altimeter dataset.  Both an instantaneous along-track sea surface height, and an along-track sampling of the mean of the model's sea surface height within each cycle, are included.

The second file, GoldStatistics.nc, is a quarter-degree gridded file derived from GoldOceanNT that contains the true answers that a map made from the along-track data is attempting to reconstruct.   For each cycle, a snapshot of the sea surface height at the cycle midpoint, the mean over the cycle, and the standard deviation over the cycle are all included.  This file uses the same quarter-degree grid as do the AVISO/CMEMS gridded altimetry products.

The following figure gives an overview of the GoldAlongTrack dataset; compare with the figure shown for the real-world data in JasonAlongTrack.