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| Titel |
Iberian and California-Oregon Upwelling Systems: trends and status of two upwelling systems at the same latitude over the last four decades. |
| VerfasserIn |
B. Barreiro, E. D. Barton |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058551
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| Zusammenfassung |
| The study of Eastern Boundary Upwelling Systems is of vital importance, given the interest
in rational management of the fisheries resources. The high level of biogeochemical activity
associated with the physical process of upwelling increases primary production and enriches
the living resources of these areas. This presentation focuses on the variability of these
physical processes on daily to interdecadal scales, in an investigation of the effects of climate
change in the Iberian and California-Oregon Upwelling Systems. The Upwelling Index (UI)
was analysed for the period 1967-2010 at 35.5-44.5ºN in both areas. The two systems differ
in that the magnitudes of upwelling intensity off California-Oregon are 3.3 higher than off
Iberia but they show a similar latitudinal behaviour. The annual/interannual scale
variability of upwelling can be represented by the recently introduced Cumulative
Upwelling Index (CUI) based on summing the mean daily UI. The seasonal cycle results
show the length of upwelling season increases southwards from 180 to 300 days
and a net upwelling occurs only for latitudes lower than 43ºN. On the interannual
scales, the CUI showed a roughly linear change at high and low latitudes (R>0.9),
with slopes between 250 and -130 m3 s-1 km-1 day-1 in Iberian and 620 and
-290 m3 s-1 km-1 day-1 in California-Oregon. The central areas (40.5-42.5ºN)
are less stable and shifted between net upwelling and downwelling over extended
periods. This information helps us contextualize the present state of the study area and
interpreted ongoing intensive process-oriented studies within the longer term variability. |
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