Table 2: RMS of the differences for the zonal component U, the meridional component V, the current modulus and the direction of the current, of the independent drifting buoy velocities and the altimeter geostrophic velocities obtained using MDT solutions CNES-CLS22, CNES-CLS18 and the CNES-CLS22 first guess. The last two lines show the reduction/increase in RMS of the differences between two solutions: CNES-CLS22 versus CNES-CLS18 and CNES-CLS22 versus CNES-CLS22 first guess, in percent (a negative percentage is a decrease in the RMS of the differences). These statistics are based on the Artic zone north of 80°N. As the CNES-CLS18 MDT has a smaller coverage, the number of points used is slightly different for this solution than for the others.