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| Titel |
Study of the Leeuwin Current from JASON-1 high rate Altimeter SLA processed with the X-TRACK software |
| VerfasserIn |
Karen Guihou, Clothilde Langlais, Peter Oke, Richard Coleman, Florence Birol |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250048638
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| Zusammenfassung |
| Satellite data are part of the ocean monitoring systems for years, providing steady and
accurate measurements. However, these data are often missing or unexploited in the coastal
area, leading to important gaps in coastal observing system.This lack of data is partially due
to an important amount of existing measurements flagged by standard processing. Indeed, the
accuracy of altimeter data decreases over shallow-waters and data within 50km off the coast
are usually not available in the official products.
Recent studies have demonstrated that a large amount of data flagged in official products
can be recovered in marginal seas and above continental shelves (Vignudelli, 2005). In this
context, the Centre de Topographie des Océans et de l’Hydrosphère (CTOH), a
french observation service dedicated to satellite altimetry, in collaboration with
different research teams, has developped a new data processing system specifically
designed to provide more altimeter data on coastal seas: the X-TRACK software.
This processing tool has shown its capacity to improve data availability near the
coastline, with strong error reductions compared to AVISO standard products (Bouffard,
2008).
In this study, we aim to determinate what new insights high sampling rate X-TRACK data
could bring on the inshore and offshore dynamics in the South-West Australia. This region is
of particular interest, as the Leeuwin Current (LC), an atypical current flowing polewards
along the west coast of Australia, is not yet well understood. If X-Track data are able
to capture a coherent dynamical signal, associated to coastal processes along the
south-West coast of Australia, it could help to improve our knowledge of this boundary
current and bring a long-time database to monitor the interannual variability of the
LC.
X-Track data have here been validated through a comparison with AVISO SLA and SST
from AVHRR. The work shows that X-Track reproduces correctly the LC dynamics and
mesoscale processes. Firstly developped for inshore applications, this study demonstrates
that X-Track data are also reliable offshore, bringing further informations than the
classical products. Hence, this data set is used to study the seasonnal and interannual
variability of the LC and its eddies. This work underlines the potential of high-resolution
altimetry in the studied region, as previously shown for the Mediterranean Sea (Birol,
2010).
References
Birol, F. and Cancet, M. (2010). Aspects of the seasonal variability of the northern
current (nw mediterranean sea) observed by altimetry. Journal of Marine Systems,
81:297–311.
Bouffard, J., Vignudelli, S., Herrmann, M., Lyard, F., Marsaleix, P., Ménard, Y., and
Cipollini, P. (2008). Comparison of ocean dynamics with a regional circulation model and
improved altimetry in the north-western mediterranean. Terr. Atmos. Ocean. Sci., Vol. 19(No.
1-2):117–133.
Vignudelli, S. P., Cipollini, L., Roblou, F. Lyard, G. P., Gasparini, G. Manzella, and
Astraldi, M. (2005). Improved satellite altimetry in coastal systems: Case study of the
corsica channel (mediterranean sea). Geophys. Res. Let., Vol. 32, L07608, 5 pp |
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