28 research outputs found
Atlas costero de temperatura y salinidad superficial en el Cantábrico
Atlas costero de la temperatura y salinidad superficial creado a partir de los datos del termosalinógrafo instalado en el B/O José Rioja, desde octubre de 2002 a diciembre de 2011 para la región del mar Cantábrico situada entre Cudillero y Santander
Recent freshening and cooling of Biscay subsurface waters
The monitoring program Radiales (https://www.seriestemporales-ieo.net/) by
the Spanish Institute of Oceanography, has been providing hydrographical and biogeochemical series in marine waters around Spain on a monthly basis from early 90's. The
proximity of the shelf-break in front of the city of Santander (SE Bay of Biscay) allowed
tracking intermediate and deep waters along the standard section perpendicular to this
city for three decades (sampling was limited to 1000 meter until late 2007, then extended
to 1500 m, and full-depth 2400 m since 2014). From the start of the sampling in nearly 90`s,
subsurface waters showed unabated warming and salt-increase. Warming was linked to
isopycnal sinking (heave) during the 90`s and early 00`s until the occurrence of very
strong winter mixing in 2005 that shifted quickly the salinity down to lower East North
Atlantic Central Waters (ENACW) levels (ca. 400 m). Overall, warming and salt-increase
at the core of ENACW added up to 0.3ºC and 0.08 in salinity within only two and a bit
decades. In 2014, the upper central waters showed freshening and cooling for the first
time in the series, a process that enhanced in the following years especially in salinity that
currently (2021) presents the lowest value of the overall timeseries. This shift in regional
hydrography follows the large salinity drop observed in the subpolar gyre around 2012
and its subsequent expansion downstream into the subtropical gyre and subarctic seas.
This regime shift implies that subsurface environmental conditions in the region have returned back to 90`s state, contrasting to the uppermost waters which continue to show
large positive anomalies. The effects of this cold and freshwater inflow in the regional
circulation of southern Biscay are discussed
Data archeology: in the pursuit of the longest sea temperature time-series on the North Spanish Coast.
Recent attempts to recover historical data show that, in general, measurements that are not incorporated into standardized databases are irretrievably lost within 10 years. However, some historical records are kept in the institutions, either due to the personal interest of some researchers, or because of good archiving practices maintained over time. The damages of paper records makes their retrieval more and more difficult, and the digitization and validation work is time and effort consuming.
Nevertheless, the old data taken time ago are invaluable for climate studies that require the longest time series available in order to establish long-term cycles and trends, as well as to incorporate them into numerical models that allow predict the ocean behavior in relation to climate change.
In the 1920s, the Santander Oceanographic Centre, (North coast of Spain), began a series of coastal measures that, with different time lapses, have been maintained over time to the present day. First repeated records of temperature at different depth levels, were made with inversion thermometers and have been kept in log books. A digitization and validation process has recently begun, which will allow the reconstruction of the longest sea temperature series in the area and their climatic characterization.
At this time, the monthly measurements carried out from 1928-1964 in the area outside the Bay of Santander have been recovered. After their validation, it is expected that they will be incorporated into the NODC's institutional database for permanent storage and reusing in future studies
New developments on Biscay-AGL Observatory. From derived products to sensor networks.
Biscay-AGL Observatory.
Since 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographical section north of Santander to a maximum depth of 2500m, as part of the IEO Radiales program. On June 2007, an ocean-meteorological buoy (AGL) was moored at the end of Santander standard section, 22nm north at 2850m depth, to complete the ocean information with the ocean-atmosphere interaction. All of them are part of IEO Observing System (1). The integrated system of AGL and its nearest hydrographic station (2600m depth) is named Biscay-AGL observatory. It is also one station for the EU FixO3 project. Joint resources and systematic analysis lead to a powerful tool, which is much more than the combination of the AGL buoy and the hydrographical samplings.
Data Access.
All AGL buoy collected data are added to the local database sited at IEO-Santander in real-time and, after rutinary automatised quality controls, they are immediately available through its dedicated webpage (www.boya_agl.st.ieo.es).
Monthly CTDO2 data from the hydrographic section are lab-calibrated in order to obtain acurated values of salinity, dissolved oxygen and density, and added to the long-term time series.
Biscay-AGL data are quality controlled, flagged and formatted according internationally agreed standards (2, 3) and routinely sent to the IEO Datacenter. This added-value controlled data are incorporated to the IEO permanent archive and made freely available through the SeaDataNet infrastructure for data access and discovery.
Derived products.
Data acquired by Biscay-AGL may be displayed as timeseries as usual, but end-users are benefited by derived products which provide direct information. A recently developed software tool produces not only timeseries of several parameters at different time resolutions but also derived products, both real and delayed time. Derived products from this buoy include, but not only, annual cycles as well as anomalous values, air-sea heat fluxes, salinity and water temperature anomalies, subinertial currents series, chlorophyll surface series, estimations of the mixed layer depth and wind and currents roses.
Sensor Web Enablement (SWE).
Sensor Web infrastructures are setup to access real-time data observed by sensors. This system has been implemented in AGL buoy sensors in order to simplify the retrieved events and alerts triggered through sensors. All those functionalities of the Sensor Web are provided in an interoperable way, following the standards stablished by the Open Geospatial Consortium (OGC). By defining standardized service interfaces, these services hides the heterogeneity of the sensor network, its communication details, enabling the access to archived sensor data that can be discovered and accessed using standard protocols and application programming interfaces
Recovering and harmonizing research cruises information
The IEO has maintained since late 60s, a local database with basic information on oceanographic campaigns, formerly known as ROSCOF reports, which were established in the framework of IODE initiatives, as a low-level inventory for future access to data. Technological advances in recent decades and different coordination activities between NODCs have favored the implementation of these reports in standardized digital formats (Cruise Summary Reports, CSR) that allow their integration in international repositories as SeaDataNet or POGO.
However, this inventory and cataloging activity has suffered ups and downs over 40 years of activity, changes in storage criteria and periods of less activity. In the search for a unique criterion that can last over time and that unifies this information as much as possible with the data generated in these campaigns, an exhaustive review of the existing information has been carried out.
The result has been the retrieval of information from short-term campaigns carried out on smaller vessels with great coastal activity, as well as updating information regarding old campaigns performed on the first half of the 20th century onboard of decommissioned
vessels. All this is completed with the systematic campaigns carried out by INTECMAR in the Galician rias, research vessels operated by the national Fisheries Administration, and information on research surveys carried out by foreign ships in national waters, forming a catalog of more than 4000 entries.
This approach is also followed by the UTM-CSIC, on its own-managed vessels and campaigns carried out since 1991. The common approach allows a unified response to the governmental needs for the planning of future campaigns, and in successive improvements in data recovering, archiving and accessing at NODC/CEDO
Fixed and Drifting Buoys around the National Spanish Waters
Improving the knowledge of the seas
surrounding the Iberian Peninsula, Balearic
and Canary islands is one of the objectives for
the Spanish oceanographic community. For
that purpose, a number of fixed and drifting
buoys have been deployed in the last 25 years. Parameters measured included sea
surface temperature and salinity, ocean
current velocity, air temperature, humidity,
wave characteristic and wind velocity. The
national aim is to increase the quantity,
quality, coverage and timeliness of
atmospheric and oceanographic data. These
observations are used immediately to improve
forecast and therefore increase marine safety