Cape Verde Ocean Observatory: Data products from a multi-platform ocean timeseries station

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Péricles Silva

National Institute for Fisheries Research (INDP)

Long-term observation is fundamental to understanding global climate change. Atmospheric change impacts marine ecosystems, and the atmosphere is influenced by ocean physical and biogeochemical processes. Many impacts and feedbacks within the climate system are centered in the Tropics and although these areas play a key role in air-sea interactions, observational data remains scarce.

The Cape Verde Ocean Observatory (CVOO) is located at 17.6°N 24.3°W and consists of operational atmosphere and ocean monitoring sites for various climaterelevant environmental parameters in the tropical Eastern North Atlantic Ocean. The observatory has three main components: a moored observatory, a research vessel and a marine laboratory.

The observatory has been collecting data since July 2006 from 3600 m of depth up to surface. It comprises sensors measuring salinity, temperature, pressure, oxygen, pCO2, ADCP, and currents. It includes a sediment trap, and a telemetry buoy for collection of near-surface data of salinity, temperature and oxygen. Since November 2012, the observatory transmits also temperature, salinity and oxygen measurements from the upper 50 meters. Data products from CVOO can be accessed from the FixO3 webpage at: http://www.fixo3.eu/service-activities/cvoo-service-activities/ where a direct link to the observatory data portal is also available.

The research vessel RV Islândia is a small fishing vessel for pelagic and bottom trawls built in 1993 in Iceland and later donated to the Cape Verdean Government. It is now under INDP’s operational responsibility. The ship has been converted from a fishing vessel to a multidisciplinary research vessel. It is equipped with a CTD rosette with twelve 5L niskin bottles. CTD sensors collect data for salinity, temperature, chlorophyll, turbidity, dissolved oxygen and light in the water. Water samples provide other parameters such as dissolved inorganic carbon, total organic carbon, total alcalinity, particulate organic carbon (POC), particulate organic nitrogen (PON) and Nutrients. The ship is has stopped operations since July 2014 due to lack of funds.

The marine laboratory is located the at INDP headquarters in Mindelo. It is operational since July 2007, and is composed of a wet and a dry lab. The laboratory is equipped with Milli-Q water, a laminar flow hood, spectrophotometer and fluorometer. It is possible to carry out analyses of dissolved oxygen, nutrients (autoanalizer), and chlorophyll.

The Ocean Science Information System (OSIS) provides meta data for all expeditions such as date, location, collected parameters and a lot more. Registered users may also access the collected data (such as CTD data) as soon as it published. The CVOO recently developed a Niskin data base implemented into OSIS and providing direct access to the calibrated bottle data. With the integrated search function the desired data can be directly accessed (e.g. “all Oxygen measurements from 2010-today north of 10°N”).

The next development of the observatory is the Ocean Science Center of Mindelo (OSCM). The OSCM is a multi-purpose facility to support the international science community in conducting marine and atmospheric research in and around Cape Verde and in hosting workshops, conferences, summer school and other meetings. Support includes, provision of laboratory facilities, offices, meeting rooms, workshop and storage spaces, access to the RV Islândia, transportation, as well as logistical services associated with housing, travel, shipment etc. issues.