STIRRING VEGETABLE SOUP

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STIRRING VEGETABLE SOUP
Adrian Martin
Warwick Turbulence Symposium Workshop March
2006"Environmental Turbulence from Clouds
through the Ocean"
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Coccolithopore Emiliania huxleyi
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100 Gt C y-1 60 land, 40 water
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(No Transcript)
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Scales of Interest Mesoscale and
sub-mesoscale 1km-500km 1d-few months
Rules of thumb eddy size 20-150km rotation
period 1-4d max.current speed 1m/s lifetime
weeks-months phytoplankton doubling time 1d
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Horizontal velocity
Vertical velocity
Data from PRIME cruise, June 1996
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Data from Dundee Satellite Receiving
Station Processed by Steve Groom, RSDAS, PML
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Given that phytoplankton and physical forcing of
phytoplankton are patchy What effect do
stirring and mixing have on production?
Suppose that upwelling and ambient regions are
isolated.
Is the total production for the area more or less
than if the two regions were being mixed?
How sensitive is the difference to A upwelling
fraction of region? I ratio of upward nitrate
fluxes? m rate of horizontal mixing?
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Parameter values
A 0.025, 0.05, 0.12, 0.25 I 1-1000 s0.006d-1
background s1.6d-1 upwelling m 0-10d-1
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139 increase in total primary production
Martin et al., Global Biogeochemical Cycles, 2002
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208 increase in total primary production
Martin et al., Global Biogeochemical Cycles, 2002
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C. Pasquero, Geophysical Research Letters, 32,
L17603, 2005
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C. Pasquero, Geophysical Research Letters, 32,
L17603, 2005
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Conclusions

• Turbulence strongly affects plankton ecology and
  plays a major
• role in controlling regional primary production
  at the mesoscale.
• Lateral turbulent stirring and mixing is just as
  important as the
• vertical supply of nutrients.
• Correlations between coherent structures and
  upwelling
• regions can exert a very strong influence on
  production.
• Use of standard effective diffusivities may
  result in significant
• overestimates of production
• Global Carbon Cycle Models may incur significant
  errors
• in ignoring the effect of mesoscale turbulence
  on biology.