January 2020: reprocessing of historical wave and wind gridded maps provided on AVISO+:

The daily delivery of wind and waves NRT maps on AVISO+ has stopped in December 2019, and the Copernicus Marine Service is now in charge of the dissemination of NRT gridded wave products (see the product page). The historical data are still available on the AVISO+ server for the needs of users' studies. However, some maps

  • were processed with too few observations and therefore gave undefined areas and
  • the files were generated with a non CF-compliant format.

Therefore, a reprocessing has been done with the changes explained in the table below. Note that there is still a difference compared to the CMEMS processing as described in the document Migration AVISO+ to CMEMS and AVISO+ to C3S (section 8). The choice to start the mapping reprocessing since 2013/09/14 is linked to the strong biases observed on the wind data before this date. The wind maps covering the period from 2009/09/14 to 2013/09/13 are therefore removed from the AVISO history. The wave maps covering the period from 2009/09/14 to 2013/09/13 do not present any instabilities and are therefore kept after reformatting the files (they are not reprocessed with the new mapping method).

  Wave maps until 2013/09/13 Wind and Wave maps since 2013/09/14
input data 
  • list of missions: see details about the processing
  • the NRT data is reprocessed compared to the 'on-the-fly' version
  • addition of S3A since 2016/06/02
processing

no change (see details about the processing)

 no change (see details about the processing)
mapping extrapolation: the figure 1 illustrates the wind extrapolation on initially non defined areas. The wind variability is conserved between the 2 versions.
format new CF compliant new CF compliant
temporal availibility WAVE: one map per day for the period 2009/09/14 to 2013/09/13 except one missing file on 2009/11/16
WIND: no maps produced		 WAVE: one map per day for the period 2013/09/14 to 2019/12/19
WIND: one map per day for the period 2013/09/14 to 2019/12/19 except one missing file on 2016/04/06
Figure 1: Wind map for 2016/01/01 with the old version (v1) and the new mapping method (v2). The extrapolation is extended to the entire grid, limiting itself to the spatial coverage of the constellation (+/- 66 ° N for Jason missions on 2016/01/01). Credits Cnes/CLS.

Figure 2 summarizes the improvements made to the wind and wave grids respectively over the reprocessed period. The new mapping method makes it possible to extend the extrapolation to the entire grid and therefore mechanically increases the number of cells defined compared to former version. There has been a marked increase in the number of cells in the wind grids from the introduction of the S3A mission. It is linked to the increase in spatial coverage up to +/- 81.5 ° N with S3A (instead of +/- 66 ° N with Jason). This increase is not observed for the wave grids because the presence of AltiKa in the constellation already made it possible to cover the high latitudes up to +/- 81.5 ° N.

Figure 2: Temporal evolution of the global mean and the standard deviation between +/- 50 ° N in the wind (top) and wave (bottom) grids, as well as the total number of cells defined on the whole grid. Credits Cnes/CLS.

HOW TO ACCESS TO DATA?

If you are already registered, the FTP access hasn't changed, please refer to MY AVISO+
If you are not registered, please select the product "Wind / Wave (grids)" in the registration form