4 Results
4.1 High-resolution CNES-CLS2022 MDT and associated
currents
The CNES-CLS22 MDT obtained is shown on Figure 4 (a) and the amplitude
of the associated geostrophic currents is displayed in Figure 4 (b).
Compared with the first guess, the CNES-CLS22 MDT contains more small
scales, gradients are tighter and currents are accelerated. Figure 5
also shows a zoom of this new CNES-CLS22 MDT (a) and the amplitude of
the associated geostrophic currents (b) over the Artic zone, as well as
a zoom of the CNES-CLS18 MDT (c) and the amplitude of the associated
currents (d). Firstly, we note that the CNES-CLS22 MDT covers the Artic
zone, which was not the case before. This is due to the improved
coverage of the CNES-CLS22 MSS used to estimate the first guess of this
new MDT. Artifacts present on the CNES-CLS18 MDT have disappeared from
the new version, for example around 110-120°E. Moreover, Beaufort gyre
is better resolved and Pan Arctic transport is visible. On the other
hand, the Beaufort Gyre tends to ”spread out” over the Canadian
Archipelago, which is not physical. In this area of the Canadian
Archipelago, the CNES-CLS22 MSS is slightly weaker (Schaeffer et al.
2023), which probably explains the poor physical representation of the
CNES-CLS22 MDT. Furthermore, the reliability of MDT is lower in areas
where observations are rare or absent, so results must be interpreted
with caution in these areas; in the European Arctic, the Kara Sea is an
example of such sparsely observed areas.