Global evaluation of the new CryoSat Geophysical Ocean Products

Francisco M. Calafat (National Oceanography Centre, United Kingdom)

CoAuthors

Chris Banks (National Oceanography Centre, United Kingdom); Paolo Cipollini (National Oceanography Centre, United Kingdom); Helen Snaith (British Oceanographic Data Centre, United Kingdom); Jérôme Bouffard (RHEA/ESRIN, Italy); Pierre Féménias (ESA/ESRIN, Italy)

Event: 2016 Ocean Surface Topography Science Team Meeting

Session: Regional and Global CAL/VAL for Assembling a Climate Data Record

Presentation type: Type Poster

Marine products from CryoSat-2 generated by a dedicated processor (CryoSat Ocean Processor or COP) have been available since April 2014. Here we present the results of a verification and scientific validation of the Geophysical Ocean Products (GOP), which have consolidated orbits and are available 30 days after acquisition. This assessment, carried out within the ESA-funded CryOcean-QCV project, is performed for the sea surface height (SSH), the significant wave height (SWH), and the wind speed. The mean value of the 20 Hz SSH anomaly (SSHA) noise corresponding to a SWH of 2 m is 6.2 cm for LRM (Low Resolution Mode) data and 10.2 cm for pseudo-LRM data. The standard deviation of the crossovers is 5.4 cm. The SSH is validated at the coast against the sea level measured by a set of carefully selected and quality controlled tide gauges, and compared with Jason-2 observations. Correlations between satellite SSH and tide gauge records are statistically significant at nearly all stations, with a mean value of 0.75 and 0.70 for CryoSat-2 and Jason-2, respectively. The Global Mean Sea Level (GMSL) curve from the GOP matches well the same curve from other altimetry missions, suggesting that CryoSat-2 is suitable for GMSL monitoring. In the open ocean the SSH is compared globally with the steric heights derived from temperature and salinity profiles as measured by Argo floats. The mean correlation between SSH and steric heights is 0.6 while the normalized RMS difference is 40%. The correlation, however, shows a strong latitudinal dependence, with higher values at low latitudes (>0.72 in the 10S- 10N band). Regarding SWH and wind speed, they are both validated against buoy observations. The SWH shows an RMS of 18 cm whereas the RMS for the wind speed is 1.3 m/s. In addition, the SWH is also compared with the values provided by the Wavewatch III model. Differences between CryoSat-2 and the WW3 are less than 20% of the SWH over most areas of the ocean
 

Poster show times:

RoomStart DateEnd Date
Grande Halle Thu, Nov 03 2016,11:00 Thu, Nov 03 2016,18:00
Francisco M. Calafat
National Oceanography Centre
United Kingdom
Francisco.Calafat@noc.ac.uk