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| Titel |
Research and operational products from the combination of a monthly hydrographic station and an oceanic buoy: The Biscay AGL fixed-point water column observatory. |
| VerfasserIn |
Alicia Lavín, Daniel Cano, Cesar Gonzalez-Pola, Elena Tel, Carmen Rodriguez, Manuel Ruiz, Raquel Somavilla |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113774
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| Publikation (Nr.) |
 EGU/EGU2015-14321.pdf |
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| Zusammenfassung |
| Long term time series are an important tool for increasing the knowledge of ocean processes
as well as for studying water masses variability in different time scales and changes and
tendencies in marine ecosystems.
Time series has been classically obtained by oceanographic ships that regularly cover
standard sections and stations. From 1991, shelf and slope waters of the Southern Bay of
Biscay are regularly sampled in a monthly hydrographic line north of Santander to a depth of
1000 m in early stages and for the whole water column down to 2580 m in recent times.
Nearby, in June 2007, the IEO deployed an oceanic-meteorological buoy (AGL Buoy, 43º
50.67’N; 3º 46.20’W, and 40 km offshore, www.boya-agl.st.ieo.es).
The long-term hydrographical record have allowed to define the seasonality, trends, and
interannual variability at all levels, including the mixing layer and the main water masses
North Atlantic Central Water and Mediterranean Water. The relation of these changes with
high frequency surface conditions has been examined using the AGL buoy data from 2007 as
well as satellite and reanalysis data.
On that context and using that combination of sources, some products and quality
controlled series of high interest and utility for scientific purposes have been developed and
are offered hourly in the web page. Main products obtained are: SST and SSS anomalies,
wave significant height character with respect to monthly average, and currents with
respect to seasonal averages. Ocean-atmosphere heat fluxes (latent and sensible) are
computed from the buoy atmospheric and oceanic measurements. Estimations of the
mixed layer depth and bulk series at different water levels are provided in a monthly
basis.
Quality controlled series are provided for sea surface salinity, oxygen and chlorophyll
data. Some sensors are particularly affected by biofouling, and monthly visits to the buoy
permit to follow these sensors behaviour. Chlorophyll-fluorescence sensor is the main
concern, but Dissolved Oxygen sensor is also problematic. Periods of realistic smooth
variations present strong offset that is corrected based on the Winkler analysis of water
samples.
The incorporation of these observatories on larger scale research programs, as done in
2003 in the framework of the VACLAN and COVACLAN projects, is important in
order to provide them with a larger spatial dimension and maximize its utility for
process-oriented studies. In 2003, the Santander section was extended 90 miles
offshore in the framework of a large-scale hydrographic and circulation monitoring
program.
Partnerships in a large EU project as FixO3 has provided tools for coordination,
homogenization and data validation as well as improve the use of chemical-biological data. |
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