Winds from SeaWinds on QuikSCAT & ERS-2 Scatterometer

Data are selected when the time difference of measurement between the two instruments is less than 4 hours, and when the distance between the centres of the SeaWinds wind cell and the closest ERS wind scatterometer footprint is less than 50 km. For wind direction comparisons : only data for which wind direction difference is less than 75 degres are selected.

Every first order statistic is calculated for data selected over 140 orbits (10 days).

The 10-day averaged wind speed differences are nearly constant, about 0.6 m/s, QuikSCAT wind speed being higher. This is confirmed by wind speed distributions, showing a larger number of low wind speed for ERS-2 than for QuikSCAT, and inversely at high wind speed.

Mean values of direction differences are very low, and the standard deviatiations are only about 20 degrees. The direction distribution is smoother for ERS-2 than for QuikSCAT, which exhibits some spikes. Due to the wide (4 hours) time window used here, the colocated data covers the whole oceans, but there are still much more data at high northern latitudes.

 

Data Period

1999

1

1999/07/19 - 00430