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| Titel |
Coastal and Oceanic SST variability along the western Iberian Peninsula. |
| VerfasserIn |
Fran Santos, Moncho Gómez-Gesteira, Maite deCastro, Isabel Iglesias |
| 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 |
250051528
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| Zusammenfassung |
| The inter-annual variability of the sea surface temperature (SST) was analyzed along the
western Iberian Peninsula in a region ranging from 9.5oW to 22.5oW and from 42.5oN
to 37.5oN with a spatial resolution of 1ºÃ1ºfrom 1900 to 2008. Both coastal and
oceanic SST showed an overall increase with warming and cooling cycles similar to
those observed in the North Atlantic region (IPCC, 2007) and in previous regional
studies: García-Soto et al. (2002) in the area close to the Celtic shelf and deCastro et
al., (2009) in the Bay of Biscay. The difference between ocean and coastal SST
(ΔSST) was not constant all over the study period. In general, ΔSST tends to increase
during the warming periods and to decrease during the cooling periods. Ocean water
is more affected by the different warming-cooling cycles than coastal water; this
different warming rate could be explained in terms of local and remote forcing factors.
According to previous research, the temperature gradient between coast and ocean is
mainly due to coastal upwelling in spring- summer (Santos et al. 2005; Álvarez
et al. 2008a) and to the water cooling developed in shallow waters at the end of
autumn due to net heat loss from surface (Fiuza, 1983; Deschamps et al. 1984). In
addition, the Thermohaline Circulation (THC) highly influences SST features in the
North Atlantic region carrying warm water from the tropics to northern latitudes.
There is a link between the THC variability and the AMO index (Ganachaud and
Wunsch, 2000). The AMO index characterizes the large-scale pattern of multidecadal
variability of SST calculated as the SST anomaly averaged for the North Atlantic region.
Macroscopically, the ocean and coastal SST follow the cycles observed at the whole North
Atlantic region (expressed in terms of the AMO index). Nevertheless, the correlation
between AMO and SST is observed to decrease coastward. Actually, the inter-annual
variability of coastal SST water is best described in terms of both THC and coastal
upwelling.
Álvarez, I., Gomez-Gesteira, M., deCastro, M., and Dias, J.M., 2008a. Spatiotemporal
evolution of upwelling regime along the western coast of the Iberian Peninsula. Journal of
Geophysical Research 113, C07020, doi:10.1029/2008JC004744
deCastro, M., Gomez-Gesteira, M., Alvarez, I., Gesteira, J.L.G., 2009. Present warming
within the context of cooling–warming cycles observed since 1854 in the Bay of Biscay.
Cont. Shelf Res. 29, 1053–1059.
desChamps, P.Y., Frouin, R., Crepon, M., 1984. Sea surface temperatures of the
coastal ones of France observed by the HCMM satellite. J. Geophys. Res. 89, 8123-
8149
Fiuza, A.F.G., 1983. Upwelling patterns off Portugal. In Coastal Upwelling. Its
Sediment Records (Part A), edited by Suess, E., Thiede, J., Plenum, New York,
85-98.
Ganachaud, A., Wunsch, C., 2000. Improved estimates of global ocean circulation, heat
transport and mixing from hydrographic data. Nature 408, 453– 457.
Garcia-Soto, C., Pingree, R.D., Valdés, L., 2002. Navidad Developmentinthe Southern
Bay of Biscay: Climate change and Swoddy structure from remote sensing and in situ
measurements. Journal of Geophysical Research 107, C8 3118, doi:10.1029/2001JC001012.
Intergovernmental Panel on Climate Change. 2007. Climate Change 2007: the physical
science basis. Contribution of Working Group 1 to the Fourth Assessment Report of the
Intergovernmental panel on Climate Change, Cambridge University Press, Cambridge,
UK.
Santos, A.M.P., Kazmin, A.S., Peliz, A., 2005. Decadal changes in the Canary upwelling
system as revealed by satellite observations: Their impact on productivity. J. Mar. Res. 63,
359–379. |
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