Merci: C. Millot, I. Taupier-Letage
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Transcript of Merci: C. Millot, I. Taupier-Letage
1NIOZ is part of the Netherlands Organisation for Scientific Research (NWO)
Koninklijk Nederlands Instituut voor ZeeonderzoekRoyal Netherlands Institute for Sea Research
Merci: C. Millot, I. Taupier-Letage
Hans van Haren (on behalf of ANTARES collaboration)
Subsidence in the deep Mediterranean
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Acoustic Doppler current profiler (ADCP)level 3 MILOM, at 169 m above bottom50 vertical bins of 2.5 m (between 2310 and 2435 m)
ANTARES neutrino telescope in W-Med
Courtesy: C. Curtil
down looking
*
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ANTARES ADCP Overview: sep 2005 - apr 2007
Current amplitude
Verticalcurrent
Relatve Echo amplitude:particles
“bad” data
storeys
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Baseline and Echo intensity data
Current amplitude
(Error)Verticalcurrent
Baseline+Echo
Amplitude
0.01 m/s ~1000 m/day
Large downward currents (W)!
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Some processes in the W-Med causing negative vertical currents
- deep-water formation (dw)- meso-scale eddies (ME)
- meso-scale currents (NC)
ME
PA
A Alps P Pyrenees
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Courtesy: X. Durrieu de Madron and collaborators
Gulf of Lions
Evidence of DW: negative currents in winter only
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Other mechanisms following DW: meso-scale
eddies?
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Chl-a day 69
susp sed day 88
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Rapid downward motions and eddies: Algerian Basin (no
DW)
39°N
37°N
39°N
37°N
38°N
38°N
7°E 8°E 9°E 7°E 8°E 9°E
van Haren, H., C. Millot, and I. Taupier-Letage, GRL 2006.
ANTARES: bioluminescent “particles”
+10--20 mm/s(5- -10 dB)
1900-2400 m
600300
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Near-bottom intrusion of dense shelf water forms well defined thermo-haline, turbidity, and fluorescence bottom anomalies
Chl-a Fluorescence (µg l-1)
“New” water stratification; TN ~ 1 hour
Courtesy: X. D. de Madron ea
TN ~ 5-8 h
More effects of DW: deep stratification
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Some peculiar Antares observations 2008
CurrentMagnitude10-3 m s-1
VerticalCurrent
10-3 m s-1
Relative Echo Amplitude
dB
First half year, similar to spring 2006
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
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Some peculiar Antares observations 2008
High frequency internal waves
CurrentMagnitude10-3 m s-1
VerticalCurrent10-3 m s-1
Relative Echo Amplitude
dB
First 3 weeks 2009
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
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Some peculiar Antares observations 2008
High frequency internal waves (~1 hour) “strong” stratification
CurrentMagnitude10-3 m s-1
VerticalCurrent10-3 m s-1
Relative Echo Amplitude
dB
Last 5 days 2008
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
2250
2300
2350
-Z (
m)
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Conclusions
-Spring 2006 large amounts particles in deep: (bioluminescent) optics confirmed acoustically
-Regular strong vertical downward currents (1000 m/day)
-Associated with meso-scale motions
-No direct evidence for local DW
-Deep stratification, following DW?,
certainly high-frequency wave motions!
The end
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Some peculiar Antares observations 2008