TY - JOUR
T1 - A global mean dynamic topography and ocean circulation estimation using a preliminary GOCE gravity model
AU - Knudsen, Per
AU - Bingham, R.
AU - Andersen, Ole Baltazar
AU - Rio, Marie-Helene
PY - 2011
Y1 - 2011
N2 - The Gravity and steady-state Ocean Circulation
Explorer (GOCE) satellite mission measures Earth’s gravity
field with an unprecedented accuracy at short spatial scales.
In doing so, it promises to significantly advance our ability
to determine the ocean’s general circulation. In this study, an
initial gravity model from GOCE, based on just 2 months of
data, is combined with the recent DTU10MSS mean sea surface
to construct a global mean dynamic topography (MDT)
model. The GOCE MDT clearly displays the gross features
of the ocean’s steady-state circulation. More significantly,
the improved gravity model provided by the GOCE mission
has enhanced the resolution and sharpened the boundaries
of those features compared with earlier satellite only solutions.
Calculation of the geostrophic surface currents from
the MDT reveals improvements for all of the ocean’s major
current systems. In the North Atlantic, the Gulf Stream is
stronger and more clearly defined, as are the Labrador and
the Greenland currents. Furthermore, the finer scale features,
such as eddies,meanders and branches of theGulf Stream and
North Atlantic Current system are visible. Similar improvements
are seen also in the North Pacific Ocean, where the
Kuroshio and its extension are well represented. In the Southern
hemisphere, both the Agulhas and the Brazil-Malvinas
Confluence current systems are well defined, and in the Southern ocean the Antarctic Circumpolar Current appears
enhanced. The results of this preliminary analysis, using an
initial GOCE gravity model, clearly demonstrate the potential
of the GOCE mission. Already, at this early stage of
the mission, the resolution of the MDT has been improved
and the estimated surface current speeds have been increased
compared with a GRACE satellite-only MDT. Future GOCE
gravity models are expected to build further upon this early
success.
AB - The Gravity and steady-state Ocean Circulation
Explorer (GOCE) satellite mission measures Earth’s gravity
field with an unprecedented accuracy at short spatial scales.
In doing so, it promises to significantly advance our ability
to determine the ocean’s general circulation. In this study, an
initial gravity model from GOCE, based on just 2 months of
data, is combined with the recent DTU10MSS mean sea surface
to construct a global mean dynamic topography (MDT)
model. The GOCE MDT clearly displays the gross features
of the ocean’s steady-state circulation. More significantly,
the improved gravity model provided by the GOCE mission
has enhanced the resolution and sharpened the boundaries
of those features compared with earlier satellite only solutions.
Calculation of the geostrophic surface currents from
the MDT reveals improvements for all of the ocean’s major
current systems. In the North Atlantic, the Gulf Stream is
stronger and more clearly defined, as are the Labrador and
the Greenland currents. Furthermore, the finer scale features,
such as eddies,meanders and branches of theGulf Stream and
North Atlantic Current system are visible. Similar improvements
are seen also in the North Pacific Ocean, where the
Kuroshio and its extension are well represented. In the Southern
hemisphere, both the Agulhas and the Brazil-Malvinas
Confluence current systems are well defined, and in the Southern ocean the Antarctic Circumpolar Current appears
enhanced. The results of this preliminary analysis, using an
initial GOCE gravity model, clearly demonstrate the potential
of the GOCE mission. Already, at this early stage of
the mission, the resolution of the MDT has been improved
and the estimated surface current speeds have been increased
compared with a GRACE satellite-only MDT. Future GOCE
gravity models are expected to build further upon this early
success.
KW - GOCE
KW - Dynamic ocean topography
KW - Ocean circulation
KW - Altimetry
U2 - 10.1007/s00190-011-0485-8
DO - 10.1007/s00190-011-0485-8
M3 - Journal article
SN - 0949-7714
VL - 85
SP - 861
EP - 879
JO - Journal of Geodesy
JF - Journal of Geodesy
IS - 11
ER -