Transcript Exchange between Elson Lagoon and the Near Shore Beaufort Sea Stephen Okkonen, UAF

Exchange between Elson Lagoon
and the
Near Shore Beaufort Sea
Stephen Okkonen, UAF
Carin Ashjian, WHOI
Robert G. Campbell, URI
USDOI Minerals Management Service - current meter moorings
National Science Foundation - water level recorders and vessel
logistics
MODIS imagery courtesy of MODIS Rapid Response Project at
NASA/GSFC.
SAR imagery obtained from Alaska Satellite Facility, UAF
Geophysical Institute.
Barrow
08 Sept 05
Courtesy Sue Moore, NOAA
10 km
Barrow
Cooper
Spring tide variability is more semidiurnal, neap tide variability is more diurnal
Barrow
Cooper
Spring current variability is more semidiurnal, neap current variability is more diurnal
10 m/sec
-10 m/sec
Projected wind 85oT
(from ~East)
Projected current 0oT
(to North)
r = 0.89
Barrow
Barrow
Cooper
Wind from ~E
Current to N
Wind from ESE
Current to WSW
r = 0.89
r = 0.88
outflow
inflow
Non-tidal inflow/outflow currents are wind driven
Non-tidal currents at Cooper are weakly correlated with SSW winds
N
Barrow currents
Tide – Out
Non-tide – In (weak)
Net – Out
Cooper currents
Tide – Out
Non-tide - Out?
Net – Out
02 Sept 06 1903 ADT
© Canadian Space Agency
Outflows from Elson
Lagoon create frontal
zones in the near
shore region
08 Sept 2005
Scores of bowhead whales observed
feeding near Cooper Island (~1315-1615h)
5 days after new moon - tide becoming
more diurnal, less semidiurnal - LW at
1032h
Barrow
Els
on
La
go
o
n
Winds from SSW at ~5 kts (~2.5 m/sec)
08 Sept 05
Courtesy Sue Moore, NOAA
2006 current meter, water level,
wind, and satellite data
Near shore fronts are associated with
outflow (tidal/non-tidal) currents from
Elson Lagoon.
Diurnal ebb (outflow) currents at Cooper
begin ~6 hr before LW and end ~6 hr after
LW
Non-tidal currents at Cooper are weakly
correlated with SSW winds
Infer the presence of near shore
front(s) maintained by ebb currents
at Cooper from ~0430h to 1630h
Fronts provide a mechanism for
aggregation of existing
zooplankton
Opportunity for efficient feeding by
whales
1338 ADT
1528 ADT
Barrow Currents
Tide – Out (beginning of ebb)
Non-tide – In
Net – In (bottom), Out (surface)
Cooper currents
04 Sept 06
1340 ADT
Tide – In
Non-tide – out (weak)
Net – In
Whales seen near ice edge front
14 Aug 05