Geoscience Reference
In-Depth Information
Fig. 9 Climatologies of (a, b) dynamic topography across 75N and (c, d) corresponding meridional
absolute geostrophic velocities: (a, c) seasonal climatologies from combined GOCE-based MDT and
altimetry and (b, d) comparison of GOCE-based MDT with MDT from ATL12, MICOM and HYCOM.
Note that in (b), each MDT is referenced to its full-region average as defined in Fig. 6
Taking benefit of the temporal variability observed in the SLA and hydrographic data,
the mean and seasonal cycle in the transport of the inflowing Atlantic Water for the period
1993-2009 can also be estimated and inter-compared as shown in Fig. 10 .
On average, the NwASC contains approximately 57 % (or 3.9 Sv) of the total mean
volume transport across the Svinøy section of about 6.9 Sv. The mean seasonal variability
reveals a pattern with largest transports (9.3 Sv) in winter being 70 % larger than the
summer transport minimum (5.4 Sv). Moreover, the mean seasonal NwASC transport
always exceeds the mean seasonal NwAFC transport, while the latter displays a narrower
range of seasonal variability in the volume transport. This suggests that the seasonal
changes of the transport across the Svinøy section are predominantly controlled by sea-
sonal changes in the transport of the NwASC.
The partitioning of these total transport estimates (both in the mean and seasonal
signals) into the respective barotropic and baroclinic components is shown in Fig. 10 b, c
and reveals distinct differences. While the transport in the NwASC is dominated by the
barotropic flow as expected along the shelf break at the Svinøy section, the transport of the
NwAFC, in contrast, is clearly larger in the baroclinic component with the exception of the
autumn period.
These GOCE-based estimates together with high-quality in situ hydrographic data are
providing new and promising abilities to examine the seasonal transport variability (total as
well as barotropic and baroclinic components) across key-selected sections. As such, it is
also providing an important tool for validations of model circulation and transports
between the northeast Atlantic Ocean and the Nordic Seas and Arctic Ocean.
Search WWH ::




Custom Search