sbi-2005 1/13 vagarities of velocity variations andreas muenchow graduate college of marine studies...
Post on 15-Jan-2016
213 views
TRANSCRIPT
![Page 1: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/1.jpg)
SBI-2005
1/13
Vagarities of Velocity Variations
Andreas Muenchow
Graduate College of Marine Studies
University of Delaware
http://newark.cms.udel.edu/~sbi
Chr
is L
inde
r, W
HO
I
![Page 2: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/2.jpg)
SBI-2005
2/13
• transmits sound then listens for echoes
• sound interacts with ~ 2-cm particles (zooplankton)
• backscattered sound received by transducers
Velocity:Radar + Sonar
Radar send and receiveelectromagnetic waves (radio, police)
Sonar send and receives acoustic waves (sound, whales)
Same physics.
75-kHz transducers:
![Page 3: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/3.jpg)
SBI-2005
3/13
Zooplankton diel vertical migrations?
ADCP backscatter Beaufort slopeOct.-2004
~10 m/hr~0.28 cm/s
![Page 4: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/4.jpg)
SBI-2005
4/13
Aagaard (1984)
![Page 5: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/5.jpg)
SBI-2005
5/13
cm/s
Beaufort Slope Currents 2003
![Page 6: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/6.jpg)
SBI-2005
6/13
Beaufort Slope Currents 2004
![Page 7: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/7.jpg)
SBI-2005
7/13
•
•
t0
t0+16 hrs
east west
L
Barrow Canyon, Sept. 1993
Synoptic velocity observation in Barrow Canyon, Alaska(view is to the south):
The flow scales with the internal deformation radius, L~5-km.
Münchow and Carmack (1996)
![Page 8: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/8.jpg)
SBI-2005
8/13
Barrow Canyon 2004
Barrow Chukchi
![Page 9: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/9.jpg)
SBI-2005
9/13
Coastal Circulation off Wainwright,Sept.-12, 2004
as measured by75-kHz acoustic Doppler current profiler
Flow is in the opposite direction from what is the canonical view of fresh Bering Sea water entering the Arctic via Barrow Canyon
![Page 10: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/10.jpg)
SBI-2005
10/13
I
II
III
Eddies in the ArcticSept.-22, 2004
I II III
USCGC Healy 75-kHz ADCP
L
D
![Page 11: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/11.jpg)
SBI-2005
11/13
The only real SBI-ADCP Survey, Sept.-22/24, 2004
55-m 100-m
red dots are XBT drops (Pickart and Kosro)
Chukchishelf
Chukchishelf
![Page 12: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/12.jpg)
SBI-2005
12/13
Warm, fresh water flows northward against gale force winds in channel while
cooler and saltier waters flow southward with the winds.
Central Channel Chukchi Shelf8-m temperature
8-m salinity
![Page 13: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/13.jpg)
SBI-2005
13/13
How to best distribute ADCP data?How to best “explore” ADCP data?
file:///Users/a2/0309_pro/os75/www0309/index.html
Conclusions:•ADCP velocity data challenges conventional perceptions of Arctic shelf and slope circulations (strong vs. weak local forcing);
•SBI did not resolve velocity and physical property fields properly in time-space domain (with the exception of WHOI moored array)
Questions:
![Page 14: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/14.jpg)
SBI-2005
14/13
ADCP Processing: Sorting and Screening Single Ping Data
water trackrelative to ship(true East, unsorted)
water trackrelative to ship(true North, unsorted)
water trackrelative to bottom(true North, sorted)
water trackrelative to bottom(true East, sorted)
Ensemble average
Ensemble
![Page 15: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/15.jpg)
SBI-2005
15/13
ADCP Calibration-1:Comparing Velocity Components
… looks good,but can’t tellhow good …
Transducer misalignment in
x-y plane: 44.1 deg.
x-z plane: 1.17 deg.
y-z plane: -1.10 deg.
Scaling by 1.021158
![Page 16: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/16.jpg)
SBI-2005
16/13
ADCP Calibrations-2:Difference of ADCP-GPS Velocity Components
North
East
Histogram Integrated Histogram
![Page 17: SBI-2005 1/13 Vagarities of Velocity Variations Andreas Muenchow Graduate College of Marine Studies University of Delaware sbi](https://reader035.vdocuments.us/reader035/viewer/2022062804/56649d645503460f94a46db9/html5/thumbnails/17.jpg)
SBI-2005
17/13
Barotropic Tidal Currents5-km data assimilation8 constituents, 2-week rms
from Erofeeva et al. (2004)