1. Royal Netherlands Institute for Sea Research
Sea research on board the
clipper Stad Amsterdam
with a focus on ocean currents and the role of
the ocean in the climate system
Prof. dr. ir. Herman Ridderinkhof
NIOZ is part of the Netherlands Organisation for Scientific Research (NWO)
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2. Our planet is blue and should not be called
‘earth’ but ‘ocean’
Measurements in the NIOZ database 2

3. Pelagia: the research vessel that is used by
the Netherlands to study the oceans
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4. Oceanographers participate in many trajects
of the Beagle voyage

5. Daily observations on board the clipper
Watersamples (in -80 freezer)
•Nutrients (P,N,Si)
•Viruses
•Bacteria
•Plankton
Sensor observations (CTD behind the clipper)
•Temperature
•Salinity
•Fluorescence
•transmission
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6. More than one million virusses per milliliter
seawater….
Daily about 1023 infections in the
ocean!
…but what are the consequences
for the functioning of the marine
foodweb? 6

7. The ocean is a very important component of
the earth climate system
 The ocean takes up CO2 from the atmosphere
 The ocean has a very large capacity to store heat and
thereby functions as a ‘memory’ for the atmosphere (and
our daily weather)
 Ocean currents redistribute heat over the planet

8. Surface circulation in the upper part of the
North Atlantic Ocean
Due to the northward heat transport and the westerly winds
the climate in western Europe is about 5 degrees warmer than
at a similar latitude in Norht America

9. El Nino: a natural oscillating climate
phenomenon with large societal
consequences

10. The average currents at the ocean surface are
known for centuries (discovered and described
by seaman)
Knowledge on theGulf
Stream has been used
for navigational
purposes since the
times of Columbus

11. A regular windfield causes a regular pattern of
surface currents: the big surface gyres in all
oceans; currents deduced from observations
from ships (dead reckoning)

12. Satellite picture of ocean temperature: the
influence of the ocean gyres in redistributing
heat is clearly visible

13. What happens in the deep sea? First observations
with German RV Meteor

14. Global overturning circulation with warm surface
currents and cold bottom currents
This overturning circulation connects all oceans and is
driven by density differences
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15. The conveyor belt: a cartoon of the global 3D
overturning deep sea circulation

16. Climate change by changing ocean currents inspires
the media, and even Hollywood…..

17. The Netherlands participates in global
research programs on the ocean circulation
Long term observations with deep sea moorings; part of
the international program OceanSITES; focus on long
term variability
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18. Measurements on currents, temperature,
salinity in the Indian Ocean (2000-2012)
Long term moorings in the
Mozambique Channel
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19. Results of NIOZ-Utrecht University study
•No continuous boundary current (currents on nautical charts
(and the Bosatlas!) are wrong)
•Ocean eddies dominate
•Mozambique eddies influence the Agulhas current and thereby
the exchange between the Indian and Atlantic ocean
•Strong year to year variability 19

20. •International research
with participation of
different disciplines
•Physical Oceanography
•Modelling
•Geology
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21. Recent knowledge: the ocean is full of
eddies that dominate the actual currents
Light
reflection by
plankton
Temperature
near
Californië
Chlorophyl near
Australië

22. Satellite measurements on the height of the
sea surface
•Red: higher sea surface
•Blue: lower sea surface
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23. Actual ocean currents can be used in
planning the route of ships (also on the
clipper Stad Amsterdam??)
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24. Oceans are characterized by their,
unobserved, large spatial variability
Recent observations
from the CTD on the temperature
clipper, Sunday 11 april
Showing
•Strong increase in
temperature (4 degrees)
•Strong decrease in
chlorophyll
chlorophyll
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25. Oceans are characterized by their,
unobserved, large spatial variability
Route of the
clipper on
Sunday 11 april
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26. Satellite observations on chlorophyll and sea
surface temperature also show large
variability
Sea surface temperature 12 april 2010
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27. Satellite observations on chlorophyll and sea
surface temperature also show large
variability
Chlorophyll 12 april 2010
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28. Oceans are very variable!
Eddies and currents in the ocean are similar to high
(low) pressure and wind in the atmosphere
Ocean current predictions will become similar to weather
predictions
Tropical cyclone Hudah, Mozambique Channel, 2000