About 100 kilometres northeast of the Cape Verde island of São Vicente, a long-term ocean observation station, the Cape Verde Ocean Observatory CVOO, has been operated since 2006. The station consists of a mooring which covers the entire water column and is supplemented by regular ship-based oceanographic sampling campaigns. The autonomous sensors installed on the mooring record data at very high temporal resolution. The ship-based sampling concentrates on the collection of data that cannot be measured autonomously.
Measurements at CVOO provide time series at selected depths of important biogeochemical and biological variables, such as carbon dioxide, dissolved oxygen, particle flux, phytoplankton and zooplankton concentrations. Data on the physical environment, such as water currents, temperature and salinity, are collected with particularly high resolution in order to accurately quantify the relevant physical processes.
The time series provide a detailed picture of the temporal evolution of oceanic variables at a single geographical location but at different depths. Only the simultaneous measurement of biogeochemical, biological and physical parameters allows the identification of various process interactions. The location of the CVOO was carefully chosen to be upwind of the Cape Verde Atmospheric Observatory (CVAO) on São Vicente. With the wind blowing rather consistently at 25 - 30 kilometers per hour from northeasterly directions, the two stations are “atmospherically connected” with each other.