surface currents in the mid atlantic bight
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8/2/2019 Surface Currents in the Mid Atlantic Bight
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Surface Currents in the
Mid Atlantic Bight
Hugh Roarty , Josh Kohut, Laura Palamara, Ethan Handel,
Greg Seroka, Erick Rivera, Scott Glenn
Coastal Ocean Observation Laboratory
Institute of Marine & Coastal Sciences
Rutgers University
ABSTRACT
The maturation of ocean observing systems now allows
scientists and engineers the opportunity to measure theocean in never before seen ways. The Mid Atlantic High
Frequency radar network has been in operation for four
years with fourteen long-range SeaSonde type HF
radars providing surface current measurements once an
hour on a continuous basis. The network spatial and
temporal coverage allows for research on the impact
and response of the Mid Atlantic Bight due to wind
forcing, stratification and river inputs. Surface currentsfrom the network during a four-year study were
summarized into seasonal and annual means. These
means were examined and compared between each
other and with meteorological observations. Thenetwork was also able to capture the surface current
response to the passage of Hurricane Irene in August
2011. Initial findings indicate that the inertial currents
are stronger on the outer part of the shelf. These inertial
currents took approximately five days to decay after the
passage of the hurricane.
YEAR LONG MEANS
SEASONAL MEAN
THREE YEAR MEAN
ALONGSHELF FLOW
TIDAL CURRENTS
HURRICANE IRENE
METHODS
44008
44014
44009
HF Radar Site
NDBC Buoy
From the three year mean the along shelf
flow was calculated every 6 km in the alongshelf direction. The along shelf current was
plotted as a function of water depth for
region 4 (red lines) and region 3 (blue lines).
The depth averaged along shelf velocityfrom the Lentz (2008) model is given as the
solid green line and the linear regression of
past current meter deployments is shown asthe dashed green line.
Region 4Alongshelf Current
Region 3Alongshelf Current
M 2 U m a j ( c m / s )
Latitude (deg)
5 MHz HF Radar Receive Antenna
5 MHz HF Radar Equipment Shed
2%
4%
6%
WEST EAST
SOUTH
NORTH
0 −2
2 −4
4 −6
6 −8
8 −10
10− 12
12− 14
14− 50
2008−2010 wind rose forbuoy44008
wind speed (m/s)
2008-2010 Wind Rose 44008
2%
4%
6%
8%
WEST EAST
SOUTH
NORTH
0 − 2
2 − 4
4 − 6
6 − 8
8 − 10
10− 12
12− 14
14− 50
2008−2010 wind rose forbuoy44009
wind speed (m/s)
2008-2010 Wind Rose 44009
2%
4%
6%
WEST EAST
SOUTH
NORTH
0− 2
2− 4
4− 6
6− 8
8− 10
10− 12
12− 14
14−
50
2008−2010 wind rose forbuoy44014
wind speed (m/s)
2008-2010 Wind Rose 44014
WINTERJan - Mar
SPRINGApr - Jun
SUMMERJul - Sep
FALLOct - Dec
39.5N 73W Surface Current Time Series >Total Current Near-Inertial Current
A) Time series of total and near inertialsurface currents during Hurricane Irene
B) Mean power for signals with periods
between 16 and 20 hoursC) U velocity time series (top) and wavelet
analysis (bottom) of grid point from A
A)
B)
C)
The surface current data was first detided using a least squares technique
that accounted for the 5 major constituents in the region (M2, S2, O1, K1 andN1). The currents were then passed through a 30 hour low pass filter. The
resultant was then averaged over a year time scale to produce the figures
above.
5 MHz HF Radar
Irene Time Series