Download The Cape Verde Ocean Observatories

Observing the Oceans for Science and Society -Climate
February 2013
The Cape Verde Observatories - Coupled Ocean and Atmosphere
Research in the Tropics
Arne Körtzinger
GEOMAR Helmholtz Centre for Ocean Research Kiel
[email protected]
The existence of global climate change is scientifically beyond doubt and has become a common place in public
discussion and opinion. Still though, our current understanding of the complex interactions of atmosphere,
hydrosphere and biosphere is rather limited, particularly with respect to the consequence and feedback potential
of climate-driven change. This is even more the case for the tropics, a key region of the global climate system, in
which ocean and atmosphere are coupled in multiple and most dynamic ways. The high scientific relevance of the
tropics in marine and atmospheric sciences is contrasted, however, with a striking lack of scientific infra-structure
and long-term observations.
Since 2004, a consortium of research institutions in
Germany (GEOMAR - Helmholtz Centre for Ocean
Research Kiel, MPI Jena – Max Planck Institute for
Biogeochemistry in Jena, TROPOS - Leibniz Institute for
Tropospheric Research in Leipzig), the UK (University
of York) and Cape Verde (INDP - National Institute for
Fisheries Development, INMG - National Institute of
Meteorology and Geophysics) have been conducting
interdisciplinary field campaigns and long-term
observations of the Earth System at or near the Cape
Verde Archipelago which has proven to be an excellent
research base. In 2006, two observatories, an oceanic
and an atmospheric site, have been established by the
partners:
1)
CVOO: The Cape Verde Ocean Observatory,
about a 100 km northeast off the coast of São Vicente
Island, consisting of a mooring in a water depth of
3700 m. Continuous measurements are made from the
multidisciplinary mooring as well as from autonomous
Activities at The Cape Verde Observatories
profiling instruments which are operated in process
study mode and telemeter their data in near realtime. The combination provides long-term data for basic parameters such as temperature, salinity, chlorophyll
fluorescence, turbidity, dissolved oxygen and dissolved CO2. More complex biological and chemical measurements
rely on monthly visits for water sampling from the RV Islândia, operated by colleagues from the INDP. Samples are
returned to a newly-equipped laboratory ashore for processing at the Institute for Fisheries Development INDP in
Mindelo or in the laboratories of partner GEOMAR. http://cvoo.geomar.de/
2)
CVAO: The Cape Verde Atmospheric Observatory is located near Calhau on the Island of São Vicente on
the windward side of the island on an ancient lava field, close to the ocean. Steady NE trade winds bring air
directly from the ocean to the measurement systems without risk of land-based contamina¬tion. The site houses
a 30 m sampling tower and five containerized laboratories with a great variety of sophisticated instrumentation
that makes continuous measurements of trace gases, greenhouse gases and aerosols as well as meteorological
parameters possible http://www.ncas.ac.uk/index.php/en/cvao-home
Both observatories have been set up in combination and allow for studying climate relevant biogeochemical
interactions between the ocean and the atmosphere in a unique way:
1)
The region is home to one of the major and most productive upwelling systems, which represents a
biodiversity hotspot that is under growing human pressure.
2)
The region features one of the ocean’s natural oxygen minimum zones, which has been shown to expand
and intensify in recent decades. This has major long-term implications for marine life.
3)
The region is the world ocean’s most prominent deposition region for mineral dust of terrestrial origin,
which has major implications for marine productivity, making it highly sensitive to climate change.
4)
The region is characterized by strong emissions of radiatively (CO2, N2O, CH4) and chemically active
(oxygenated and halogenated) trace gases, which have significant implications for atmospheric properties.
The sustainability of the young Cape Verde Ocean and Atmosphere Observatories depends critically on the
development of a modern and versatile local research infrastructure. Better understanding of the complex
climate system is a prerequisite for adequate adaptation and mitigation strategies. The research institutions
above mentioned have made a strong commitment to research in the tropics at Cape Verde in an internationally
visible way. Currently GEOMAR and INDP are establishing a fully-fledged research centre in close neighborhood
to the existing INDP. The centre will host laboratories, offices and seminar rooms, workshops, a large hall and
technical infrastructure for repair, maintenance and storage of oceanographic equipment. The station and its
linked infrastructure of CVOO and CVAO shall be available to both the national and international marine scientific
and atmospheric community and provide opportunities for capacity building in whole West Africa.