|Title||Jason-2 OGDR Wind and wave products: random error estimation|
|Publication Type||Technical memorandum|
|Secondary Title||ECMWF Technical Memoranda|
|Authors||Abdalla, S, Janssen, PAEM, Bidlot, J-R|
Triple collocation technique is used to estimate the errors in Jason-2 fast delivery OGDR-BUFR wind and wave products. Significant wave height (SWH) error is estimated by collocating Jason-2 product with buoy and model hindcasts over a period of a year from 1 August 2009 and 31 July 2010. It is estimated that Jason-2 absolute SWH error is about 0.13 m or about 5.4% relative to the mean SWH value. For the collocations considered here, Jason-2 wave height error is the lowest among the other sources of data: ENVISAT RA-2 with about 6.2%, Jason-1 with about 7.8%, the buoys with 8.6% and finally the stand-alone model hindcast with about 9.7%. The wind speed error is estimated by collocating Jason-2 product with buoy and ECMWF model 1-day forecast over the same period. The altimeter wind speed error of Jason-2 turned out to be 1.0 m.s-1 ( 11.9% of the mean). Although this is not the lowest error among the others, it is not too far from that. For the collocation data used, it is found that wind speed errors of ENVISAT RA-2, Jason-1 altimeter, the buoys and the model 1-day forecast are, respectively: 0.9 m.s-1, 1.0 m.s-1, 1.2 m.s-1 and 1.0 m.s-1.