American Fisheries Society talk

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Circulation and Mixing in the Hudson River based
on Observations and Modeling
Alan F. Blumberg Stevens Institute of
Technology Hoboken, NJ and Ferdi L.
Hellweger Columbia University New York City, NY
March 22, 2003
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Physical ProcessesGoverning Transport

• Advection river inflows, net flow
• Dispersion tidal movements
• Salt driven estuarine circulation

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Ho et al. Environ. Sci. Technol. 2002
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(No Transcript)
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TEMPERATURE SALINITY
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FRESHWATER INFLOW (Green Island, Monthly Average)
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SALINITY AT CROTON ON HUDSON
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SALINITY AT PEEKSKILL
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Troy, NY
Data 14 days 2,060 Samples (?) ?t 2 min ?x
400 m Vertical profiles (?) Model ECOM Time-var
iable 1,191 Boxes 10 Layers ?x 600 m ?z 1
m Output 400 MB
Release 1.6 mol SF6
Newburgh Bay
NYC
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SF6 CONCENTRATION fmol L-1
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LONGITUDINAL PROFILES
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Secondary Peaks Tidal Trapping
Asymmetry Estuarine Circulation
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100
100
100
WAPPINGER CREEK
1,000
1,000
100
10,000
1,000
1,000
1,000
1,000
1,000
SF6 CONCENTRATION fmol L-1
1,000
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Conclusions

• Large tidal flows 40 cm/s (ebb dominant)
• Tidal excursion up to 20 km
• Spatial structure evident
• Freshwater inflows quite variable
• Net advection 0.5 to 3 km/day
• Tracer based dispersion 70 m2/s
• - Salt intrusion
• - Tidal trapping
• for more information email ablumber_at_stevens-te
  ch.edu
• presentation online at www.columbia.edu/flh23