Approved for Public Release;
Distribution Unlimited.
ENVPREDRSCHFAC
Technical Note No. 3-74
COMPUTATION OF TIDES, CURRENTS AND DISPERSAL
OF POLLUTANTS IN LOWER BAY AND APPROACHES TO
NEW YORK WITH FINE AND MEDIUM GRID SIZE
HYDRODYNAMICAL-NUMERICAL MODELS
By
T. LAEVASTU
in collaboration with
M. CLANCY and A. STROUD
Part 3 of a series of four reports
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
PACIFIC NORTHWEST ENVIRONMENTAL
RESEARCH LABORATORY
CORVALLIS, OREGON
JANUARY 1974
ENVIRONMENTAL PREDICTION RESEARCH FACILITY
NAVAL POSTGRADUATE SCHOOL
MONTEREY, CALIFORNIA 93940
-------
UNCLASSIFIED
SECURITY CLASSIFICATION OF THIS PAGE (Whtn Data £nlarod)
REPORT DOCUMENTATION PAGE
READ INSTRUCTIONS
BEFORE COMPLETING FORM
1. REPORT NUMBER £ \/P RE D RS C H F AC 1. GOVT ACCESSION NO,
Technical Note No. 3-74
3. RECIPIENT'S CATALOG NUMBER
4. title^""'"'^Computation of TicleSt Currents
and Dispersal of Pollutants in Lower Bay
and Approaches to New York with Fine and
Moclefs ®rlc* Size Hydrodynamical-Numerical
S. TYPE OF REPORT ft PERIOO COVERED
•. PERFORMING ORG. REPORT NUMBER
7. AUTHORfa;
T. Laevastu with M. Clancy and A. Stroud
CONTRACT OR GRANT NUMBERfaJ
9- PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Prediction Research Facilit
Naval Postgraduate School
Monterey, California 93940
tO. PROGRAM ELEMENT. PROJECT. TASK
y AREA ft WORK UNIT NUMBERS
11. CONTROLLING OFFICE NAME AND ADDRESS
Naval Air Systems Command
Department of the Navy
Washington, D.C. 20361
12. REPORT DATE
January 1974
t). NUMBER OF PASES
57
i4. MONITORING AGENCY NAME a AODRESSf/f d//farant /rem Cofifro/linfi Ollico)
IS. SECURITY CLASS, (at Mo nport)
UNCLASSIFIED
11a. DECL ASSI Fl C ATI OH/DOWNGRADING
SCHEDULE
16- DISTRIBUTION STATEMENT (ol lhl» Ropert)
Approved for Public Release; Distribution Unlimited.
t7. DISTRIBUTION STATEMENT (of th» abattael anfarad In Block 30, II dlllmrml from Raport)
18. SUPPLEMENTARY NOTES
19. KEY WORDS (Cont/nu* on rar«r« old* II nacaaaarr and Idmtllr by block numbor)
Hydrodynamical-Numerical Model
Computation of tides and currents
Dispersal of pollutants
New York Harbor
20. ABSTRACT (Contlnuo on ravaraa aJda II nacaaaaiy and Idmtlty bf block nun bar)
The report summarizes the-results—of two different HN
model applications with different grid sizes: one with a small
grid size for the Lower Bay of New York; and the second with a
larger grid size for the Approaches to New York, which includes
part of the New York Bight outside the Ambrose Channel.
DD ijan*73 1473 IS0B80LETE UNCLASSIFIED
S/N 0102 014 6601 | SECURITY CLASSIFICATION OP THIS PAGE fVhan Dim Mntfd)
-------
UNCLASSIFIED
AIIJHITY CLASSIFICATION OF THIS PAGEOThen Data Entered)
20. (Continued)
The tides are prescribed at the open boundaries of these
models utilizing the available tidal harmonics, and interpo-
lating between the end points, if necessary, (in the larger
grid model). For verification, the available tidal harmonics
inside the grids are used (which were not used for the input
at the boundaries) .
A uniform wind field was introduced in some of the model
runs representing the average prevailing wind during summer
or winter. The results with winter wind conditions are given
in this report. Furthermore, the outflow from the Hudson River
and that coming from Long Island Sound through the East River was
prescribed either in the river itself in the fine grid model,
or at The Narrows in the coarse grid model.
The currents within the Lower Bay and its Approaches are
essentially tidal as known already from the excellent work of
Marnier ( 1935). The behavior of the outflowing water from The
Narrows is best seen in the rest current (i.e., the net current
after a full tidal cycle) computation, which shows the turning
of the main flow to the right under the influence of Coriolis
force. The strongest outflow from the Lower Bay flows past the
Sandy Hook. On the opposite northern shore of the entrance to
the Lower Bay (off Coney Island), a weaker outflow can be
recogn i zed.
The experiments on the computation of dispersion and diffu-
sion of pollutants is given. The results show a very rapid
dispersion of the pollutants within the Lower Bay under the
influence of relatively strong tidal currents in relatively
shallow water, with a few peculiarities of the distribution as
dictated by the distribution of the tidal current patterns.
One of the peculiarities is the slow dispersion off Staten
Island at the entrance of Raritan Bay.
The general conclusions of this numerical study can be
summarized as follows:
(1) The numerical model reproduces well the currents as
known from earlier empirical studies, but presents many more
details and makes it possible to compute other current-
dependent processes, such as transport and diffusion.
(2) The flushing of the Lower Bay NE of the line between
The Narrows and Sandy Hook is considerably more rapid than in
the area SW of this line towards Raritan Bay.
(3) There is a weaker outflow from the Lower Bay between
the Ambrose Channel and Coney Island (off the Long Island coast),
and the main outflow is between Ambrose Channel and Sandy Hook,
and turns toward the south along the New Jersey coast.
UNCLASSIFIED
SECURITY CLASSIFICATION OF THIS PAGEfTHian Data Bntirtd)
-------
FOREWORD
This report contains a summary of the essential results
of the application of single-layer vertically integrated
hydrodynamical-numerical models on the Lower Bay and Approaches
to New York. It describes the results of computation of tides*
currents and dispersion of pollutants in the area.
Wherever possible, and where available data so allows,
attempted verification of the results is presented. Much more
generated data are available in the form of computer printouts
and graphical plots than was possible to present in this
report. These printouts will be available at the EPA labora-
tory in Corvallis.
Numerous tests and experiments with the model are reported
only briefly in this report. Some of the model tests are
summarized elsewhere in this 4 part series together with des-
criptions of the numerical models.
This project was a joint cooperative effort of EPA and
EPRF. Besides the direct application of the model for the
area concerned in this report, considerable experience and
verification results obtained from other applications of this
model are indirectly incorporated in this work.
-------
CONTENTS
FOREWORD iii
LIST FIGURES . vi
1. INTRODUCTION 1
2. THE SMALL GRID SIZE MODEL FOR THE LOWER BAY 3
2.1 The Inputs into the Model 3
2.2 The Sea Level and Currents 3
2.3 Transport and Dispersion of Pollutants 5
3. THE MEDIUM GRID SIZE MODEL FOR THE APPROACHES .... 6
3.1 The Inputs into the Model 6
3.2 The Sea Level and Currents 6
3.3 Transport and Dispersion of Pollutants ..... 9
REFERENCES 11
-v-
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Page
12
13
14
15
16
17
17
17
18
18
18
19
19
19
20
20
21
22
23
LIST OF FIGURES
Computational grid for Lower Bay with
indications of the locations of special
output points
Comparison of tides at Sandy Hook. - computed
withHN model at grid 16,28;-- harmonic
tidal curve
Currents 2 hours after high water at Sandy
Hook; wind 10 m sec"' from NW
Currents 2 hours after low water at Sandy
Hook; wind 10 m sec-1 from NW
Rest currents after a full tidal cycle;
winds, 10 m sec"' from NW .
Currents
at
Point
1;
winds
10
m
sec"
from
NW
Currents
at
Poi nt
2;
wi nds
10
m
sec"
from
NW
Currents
at
Poi nt
3;
wi nds
10
m
sec"
from
NW
Currents
at
Point
4;
wi nds
10
m
sec"
from
NW
Currents
at
Poi nt
5;
wi nds
10
m
sec"
from
NW
Currents
at
Point
6;
wi nds
10
m
sec"
from
NW
Currents
at
Poi nt
7;
wi nds
10
m
sec"
from
NW
Currents
at
Poi nt
8;
wi nds
10
m
sec"
from
NW
Currents
at
Poi nt
9;
wi nds
10
m
sec"
from
NW
Currents at Point 10; winds 10 m sec"1 from NW
Currents at Point 11; winds 10 m sec"1 from NW
Concentrations after 1 hour from
instantaneous release (10000 units)
Concentrations after 7 hours from
instantaneous release (10000 units) .....
Concentrations after 13 hours from
instantaneous release (10000 units)
-vi-
-------
LIST OF FIGURES (cont. )
Fi gure Page
20 Concentrations after 19 hours from
instantaneous release (10000 units) 24
21 Concentrations after 25 hours from
instantaneous release (10000 units) 25
22 Computational grid (medium) for Approaches
to New York Bight with indication of
locations of special output points and
sections 26
23 Sea level changes (tides) at Sandy Hook as
computed with HN model and compared to
harmonic predictions 27
24 Sea level changes (tides at Ft. Hamilton as
computed with HN model and compared to
harmonic predictions 28
25 Sea level and currents at Point 1 ...... 29
26 Sea level and currents at Point 6 30
27 Sea level and currents at Point 8 31
28 Sea level and currents at Point 11 32
29 Sea level and currents at Point 12 33
30 Sea level and currents at Point 13 34
31 Sea level and currents at Point 14 35
32 Currents during high water at Sandy Hook ... 36
33 Currents 2 hours after high water at Sandy
Hook 37
34 Currents 2 hours before low water at Sandy
Hook 38
35 Currents during low water at Sandy Hook ... 39
36 Tidal currents at high water at Sandy Hook
(after Marmer, 1935) 40
- v i i -
-------
LIST OF FIGURES (cont.>
Figure Page
37 Tidal currents at low water at Sandy Hook
(after Marmer, 1935) 41
38 Comparison of currents at or near the
position of Scotland Lightship, A currents
computed with HN model (spring tides) at
grid point 12,31; B mean tidal currents at
Scotland Lightship (40°26.6'N, 73°55.2'W)
(from Marmer, 1935) 42
39 Computed currents at Point 7 43
40 Computed currents at Point 11 43
41 Computed currents at Point 12 43
%
42 Computed currents at Point 13 44
43 Computed currents at Point 14 . 44
44 Rest currents after a full tidal cycle .... 45
45 Transport of water through section AA1 in
m3 sec"' 46
46 Transport of water through section BB2 in
m sec"1 47
47 Transport of water through section CC3 in
m sec" 48
48 Transport of water through section DD4 in
m sec" 49
49 Computed distribution of "pollutants" after
7 hours from release (instantaneous release
10,000 units, continuous release 360 units
per hour) . 50
50 Computed distribution of "pollutants" after
17 hours from release (instantaneous release
10,000 units, continuous release 360 units
per hour) 51
- v i 1 i
-------
I. INTRODUCTION
There are great variations in the dynamical behavior of
the waters in bays, estuaries and in coastal areas as well as
resultant differing behavior of pollutants introduced into
those waters. It is not possible to cover all areas, times
and conditions with measurements, thus the solution to many
of the scientific as well as practical problems related to
the dynamics of these waters can be found in proper numerical
modeling of the behavior of the estuarine and coastal waters.
The Hydrodynamical-Numerical (HN) models of the W. Hansen
type provide the means for such a solution. These models have
been appliied for a number of years with relatively great
success on a variety of problems in coastal and semi-closed
seas.
The following report presents the results of the applica-
tion of two models on the New York Bight, the models varying
only in grid size and input parameters as well as in treatment
of some input parameters such as bottom friction and horizontal
eddy viscosity.
As currents are available from the models in small time
steps at each grid point, the dispersion and diffusion equation
was solved in Lagrangian. Several different numerical methods
of dispersion and diffusion computations have been tested, and
the results of the best model are presented in this report.
As considerable numerical material was created during this
work, it is not possible to present all in this summary report.
However, the computer outputs will be available at the EPA
laboratory in Corvallis, Oregon for solving any detailed
problem.
In a larger modeling effort, many people are involved and
it is not always possible to acknowledge everyone by name.
However, the authors wish to express their special thanks to
Miss Kathy Viars and Miss Jodi Fisher, for digitization of
- I -
-------
bottom data and typing the original manuscript. Furthermore,
Mrs. Winona Carlisle prepared all the final copy for repro-
duction. The numerous figures were drafted by Mr. James Pool
and some by Miss Jodi Fisher.
- 2 -
-------
2. THE SMALL GRID SIZE MODEL FOR THE LOWER BAY
2.1 THE INPUTS INTO THE MODEL FOR THE LOWER BAY
The computational grid for a fine grid model for the
Lower Bay is given in Figure 1. This figure also shows loca-
tions of special output points.
. The grid size of the model is 460 meters. The maximum
depth in the computational area required a relatively short
time step of 18 seconds.
The tides were introduced at the open boundary using
four major tidal harmonic constants for Sandy Hook. The
Arthur Kill was kept open for in and outflow, as was The
Narrows. However, besides the computed flow through The
Narrows, additional current components were prescribed at each
time step just outside The Narrows so that a steady additional
flow of 30,000 cubic feet per second was obtained. This flow
also includes the net transport from the East River. The model
was run without winds as well as with typical winds for summer
(9m sec"^ from SW) and winter (10 m sec"^ from NW).
2.2 THE SEA LEVEL AND CURRENTS
A comparison of tides computed with the HN model and
those predicted with the harmonic constants at.Sandy Hook are
shown in Figure 2. Similar good agreements between tides,
computed with available harmonic constituents and the sea level
data extracted from the model run were also obtained at Fort
Hami1 ton.
Figure 3 gives a snapshot look at the currents two hours
after high water at Sandy Hook with a wind of 10 m sec~V from
the NW. The outflow from The Narrows and from the Lower Bay in
general may be observed. There is still some inflow into
Arthur Kill. The outflowing water is turning toward the
South, outside the Lower Bay, and there is a considerable
conversion along the eastern part of the Ambrose Channel.
- 3 -
-------
Figure 4 shows a snapshot picture of currents two hours
after low water at Sandy Hook. At this time there is a net
inflow into the Lower Bay. There is still an outflow from
The Narrows and slight outflow from.the Arthur Kill, with
resulting convergence in the western part of the Lower Bay
(in Rari tan Bay).
Figure 5 shows the net currents after a full tidal cycle
in Lower Bay with a wind of 10 m sec"^ from NW. There is an
outflow from The Narrows and a small outflow from Arthur Kill
and a net outflow from the Lower Bay in general. The outflow
from The Narrows is essentially that programmed in, as men-
tioned earlier. It should be noticed that this outflow turns
initially to the right as affected by Coriolis force. The
net outflow turns toward the south along Sandy Hook.
The currents at various special output points (indicated
in Figure 1) are shown in Figures 6 to 16. These data are
extracted from a run with winds of 10 m sec"^ from the NE.
The tidal ellipses are asymmetrical and a net flow is apparent
at each point. Points 1 and 2 (Figures 6 and 7) are outside
the Lower Bay. At Point 1 the currents are affected by the
Ambrose Channel, whereas at Point 2 the currents are flowing
toward the SSW along the New Jersey coast (this was also
noticed by Marmer, 1935). The ebb at nearly all.points near
and at the entrance to Lower Bay lasts longer than the flood --
a condition also observed by Marmer, 1935. At Point 3
(Figure 8) (off Coney Island), the ebbing currents flow toward
the ESE. At Point 4 (Figure 9) there is nearly always an out-
flow from the bay. This point is located in the Ambrose
Channel. The outflow dominates also off Sandy Hook (Point 5,
Figure 10) and is stronger here than off Coney Island. The
currents are usually weaker inside the Lower Bay (Figures 11,
13, 14, and 15). There was a net outflow programmed through
The Narrows (Figure 12).
- 4 -
-------
Point 11 is located on the slope of a channel leading
into Arthur Kill, which was left open for in and outflow in
the program. The strong currents at the slope of this channel
are thus shown in Figure 16. As the channel had no restric-
tions in the model, the computed flow might be somewhat
stronger than observed at this location. It should be noted
that the strength of the current is not necessarily proportional
to the transport as the currents can be considerably stronger
over shallow water, but the transport can be relatively sma.ll
because of the shallow depth.
2.3 TRANSPORT AND DISPERSION OF POLLUTANTS
Experimental release of pollutants were made in the model.
The release points can be seen in Figure 17, which also gives
the distribution of concentrations one hour after release.
Figures 18 to 21 show the distribution of the pollutant with
time at 6-hourly intervals. The most remarkable aspects of
these distributions is that the release in the central part of
the bay has a small dispersion rate and that the pollutants
released off The Narrows are carried out relatively rapidly
from the Lower Bay with the net outflow caused by the fresh
water flow from the Hudson River.
- 5 -
-------
3. MEDIUM GRID SIZE MODEL FOR THE APPROACHES TO NEW YORK
3.1 THE INPUTS INTO THE MODEL
The model computational grid for the Approaches to New
York is shown in Figure 22. The grid size is 1.852 km and
the computational time step was 30 seconds. The open boundary
imput was derived from harmonic constituents off Atlantic City
and Sandy Hook at one end (extrapolation between those points),
and from the interpolation of harmonic constituents between
Sandy Hook and Montauk Point at the other end. The Hudson
River flow was prescribed in the river itself and the flow
through The Narrows was also given at each time step. The
flow through The Narrows also includes the flow from Long
Island Sound through the East River. Furthermore, the Arthur
Kill was open and flow was possible around Staten Island.
The passage from Upper Bay to Long Island Sound was programmed
one grid wide and no attempt was made to restrict it at Hells
Gate, where the East River is only 850 feet wide and 30 feet
deep.
Various winds were used in the computations to investi-
gate the effects of the wind. The typical summer conditions
were presented with the winds from the SW at 9 m sec-^ and
the winter conditions with the winds from NW at 12 m sec"^ .
Figure 22 shows the locations of the special points where
outputs were taken as well as the points where numerical
experimental release of pollutants was effected in the computa-
tions. Furthermore, this figure shows some sections through
which the transport was computed.
3.2 THE SEA LEVEL AND CURRENTS
The computations were done with near spring tidal input.
The verification of the results are shown in Figure 23 with
Sandy Hook tidal data, and in Figure 24 with Fort Hamilton
data. The agreement between HN model and harmonic tides is
- 6 -
-------
relatively good, considering that the outputs from the HN
models are not taken at exactly the same location where the
tide gauge is located but from a point nearby which is usually
located in deeper water. It is possible to adjust the boundary
inputs in the HN model to correctly reproduce the tidal eleva-
tion in a specified time period at the grid points within the
computation area. However, this tuning was not applied in the
general application study of the models presented here.
The outputs from the special points (see Figure 22) are
given in Figures 25 to 33 in the form of tides as well as
current direction and speed for every two hours. Figure 25
shows the sea level and currents at Point 1 which is located
in Long Island Sound. Figure 26 shows the sea level and
currents in the middle of Lower Bay. As is apparent from
these two figures and known from observations (Marmer, 1935),
there is a time difference between high and low water in Lower
Bay and that in Long Island Sound, creating hydraulic currents
in the East River. The tidal range at the west end of Long
Island Sound is about 7.1 feet and in the Upper Bay about 4.5
feet, creating a hydraulic head at times of about 3 feet.
Furthermore, the time difference of high and low water is
about 3 hours. As a result, the hydraulic currents in the
East River average about 2 knots (see also Figures 32 to 35)
which is in agreement with Marmer's (1935) observations.
The slack water in Lower Bay is about 1 hour after high
or low water and the tidal current comes to strength about
1-1/2 hours thereafter.
Figure 27 shows the currents in the middle of the Ambrose
Channel and Figure 28 shows the sea level and current changes
north of Barnegat Bay. These two figures demonstrate again
the well known fact that the time of change of current in
relation to tide height is variable. In general, the current
turns earlier in shallow water near shore and latest in the
Ambrose Channel. The flooding current in the Ambrose Channel
- 7 -
-------
sets toward the NW, a fact also observed by Marmer (1935).
The ebbing current off the New Jersey coast (Figure 28) sets
toward the south and is stronger and lasts longer than the
flooding current. Figures 29 to 31 show the currents in the
Approaches to the New York Bight and amplify to some extent
the observation on the relationship between tide and current
made above.
Figure 32 gives a snapshot picture of the currents during
high water at Sandy Hook. Figure 33 shows the same currents
two hours after high water at Sandy Hook when the tide turns
from flood to ebb. Figure 34 shows currents two hours before
low water (i.e., ebbing currents) and Figure 35 shows the
currents during low water at Sandy Hook.
Figure 36 (from Marmer, 1935) shows the currents during
high water and Figure 37 shows the current picture during low
water as ascertained by Marmer (1935). These pictures are
essentially the same as computed with HN models except the
figures from Marmer (1935) do not give sufficient details.
A comparison of the currents computed with the HN model
approximately at the location of Scotland Lightship and the
mean tidal currents as measured at Scotland Lightship and
reported by Marmer (1935) are given in Figure 38. Although,
the currents computed with the HN model are about 15% higher
than those reported by Marmer, it should be borne in mind
that Marmer gives mean tidal currents whereas near spring tides
were used to compute the currents with the HN model. Thus,
in reality, the agreement between the real currents and those
computed might be better than shown in this figure. It
could be pointed out that the strength of tidal currents is
often given in tables as mean tidal currents, which presents
the strength of ebb or flood current multiplied by 0.637.
Figures 39 to 43 show the computed currents (without wind) at
various output points. In comparing Figure 41 with Figure 39,
it will be noticed that the current elipse away from the coast
- 8 -
-------
is widening (as known from empirical tidal measurement) and
that the tidal currents are somewhat stronger in shallower
water along the coast than further offshore.
The rest currents after a full tidal cycle, without the
wind, are shown in Figure 44. They depict the general circula-
tion in the Approaches to New York. The net outflow from
Lower Bay and from The Narrows, and the slight net circulation
around Staten Island, are well depicted. The net flow from
the East River is known from earlier empirical studies (see
Marnier, 1935). The general circulation outside the entrance
to Lower Bay is well depicted in Figure 44 (westward flow off
Long Island turning to stronger southward flow off the New
Jersey coast) including the "forking" of currents off the
head of Hudson Submarine Canyon (SSE of Scotland and Ambrose
Lightships), which has been observed by Ketchum, Redfield and
Ayers (1951).
3.3 TRANSPORT AND DISPERSION OF POLLUTANTS
The transport through four sections are shown 1n
Figures 45 to 48. Figure 45 shows the transport through The
Narrows. The computed transport here may be in excess, as
the Arthur Kill, Kill Van Kull and East River were presented
in the model wider than they are in reality. Figure 46 shows
the transport through section BB2 indicating a slight SW trans-
port excess which is also apparent in Figure 48 showing the
transport through section DD4. Figure 47 shows the transport
through section CC3 in and out from the Lower Bay. This
figure shows an outflow from Lower Bay slightly in excess of
the river flow into Lower Bay. According to Ketchum, Redfield
and Ayers (1951) the Hudson flow varies between 600 to 5500
3 3 -1
cubic feet per day -- the average flow being 25x10 ft sec
The average flow of fresh water into Lower Bay was estimated
3 3 -1
by Ketchum, et al_, to be 47x10 ft sec . This excess of
fresh water flow is only a small fraction of the tidal flow.
Thus the HN model computations confirm the conclusions of
- 9 -
-------
Ketchum, e^t aj_, that the flushing rate of the New York Bight
is independent of the rate of river flow and that the tidal
oscillations are predominantly important in the flushing of
such regions as New York Lower Bay. Preliminary computations
of the flushing time of Lower Bay with tides gave a value of
7 days. This is in good agreement also with estimates by
Ayers (1951) and Ketchum, Redfield, Ayers (1951) of the
flushing of the Bight outside Ambrose Channel between Cape
May and Montauk Point.
Figure 49 shows the distribution of "pollutants" 7 hours
after release, whereby the release was either 10,000 units
at a given grid point for instantaneous release, or 360 units
per hour at continuous release point (for location of release
points, see Figure 22). Figure 50 shows the same distribution
17 hours after the release. As is apparent from Figure 50,
the dispersion is strongest where the currents are stronger
such as inside Lower Bay off The Narrows. The lower con-
centrations in Lower Bay are due partly to the flushing effect
of the net flow through the The Narrows. It should also be
noticed that any release at the Ambrose Channel and at the
Hudson Submarine Canyon tends to move the polluted waters
faster toward the New York Approaches and the Lower Bay during
flooding current. The pollutants from the western end of Long
Island Sound move into New York harbor through the East River.
It is also apparent in Figure 49 that in the middle of Lower
Bay the concentrations remain higher as it was illustrated
with the release in fine grid model. The pollutants released
off the south coast of Long Island move toward the entrance
to Lower Bay. However, pollutants released off the New Jersey
coast move rapidly toward the south along this coast away from
New York Bight proper.
- 10 -
-------
REFERENCES
Ayers, J.C., 1951: The normal flushing time and half-life of
New York Harbor. Status report to ONR (N6 onr 264, task
15), ms rpt.
Haight, F.T., 1942: Coastal currents along the Atlantic Coast
of the United States. U.S. Dept. of Commerce, Coast and
Geodetic Survey, Spec. Publ. 230:73 pp.
Ketchum, B.H., A.C. Redfield and J.C. Ayers, 1951: The oceano^
griaphy of the New York Bight. Papers in Phys. Oceanoqr.
and Met. Cambridge and Woods Hole, 12(l):1-46.
Marmer, H.A., 1935: Tides and currents in New York Harbor
U.S. Dept. of Com
FuFTT 111:198 pp7
U.S. Dept. of Commerce, Coast and Geodetic Survey, Spec.
Reports in this series:
Part 1: A vertically integrated hydrodynamical-numerical
model (W. Hansen type): Model description and
operating/running instructions.
Part 2: A multi-layer hvdrodynamical-numerical model
(W. Hansen type): Model description and operating/
running instructions.
Part 3: Computation of tides, currents and dispersal of
pollutants in Lower Bay and Approaches to New York
with fine and medium grid size hydrodynamical-
numerical models (this report).
Part 4: Computation of tides, currents, and dispersal
of pollutants in the New York Bight from Block
Island to Atlantic City with large grid size,
single and two-layer hydrodynamical-numerical
models.
-II-
-------
74 1 5
40 15
N3
I
74 10
-------
10
Figure 2
COMPUTED (HN)
PREDICTED
(HARMONIC)
20
TIME (Hours)
Comparison of tides at Sandy Hook
Computed with HN model at grid 16, 18
Harmonic tidal curve
-------
40°30' 74°15' 74°10 40*35' 7405' 74°00'
m m ss as m ssa m =sa
30C VWf tyyl 'JOO^ >jCm %v
um mut&m&m®
mw,imMmmmm®
;«r'Mmmmmmmm
ll
MrZ<£,
'T #!£,
VaMTa
74 IS
T?^3#i»«a8ai#
VI av VJA xa XXX mv vjft Ajjy w
Lv>«t »?«>KswhSot5wf «?
B6:S?$*ffS!SK*
LIIMKlillli
MIIIRIfiHI
v*H ¦¦¦'«¦»¦
iirjHar «»!«?».*
£
-------
40°30' 74*15' 74*10' 40°35' 74*05' 74° 00
Ln
mm
mm
mm
UM I
:iHr%g*3iM
ji $# 3
w ¦ ! ¦ ¦! ¦ Vili'M i
74*10'
74*15'
4tf25'
4
-------
40*30 ' 74°15'
74 10
40 35
74° OS'
74°00
a-
i
40°30
74°1S'
40°25'
74*10'
74°05' 74 00' 40°2 5' 73° 55'
Figure 5 Pest currents after a full tidal cycle; winds 10m sec"1 frcm NW
-------
Figure 6
Currents at Point 1 (location see Figure 1);
winds 10m see-* from NW
Figure 7
Currents at Point 2 (location see Figure 1);
winds 10m sec"l from NW
Figure 8
Currents at Point 3 (location see Figure 1);
winds 10m sec'l from NW
0 20 40 60 80
*
cm/sec
- 17 -
-------
Figure 9
Currents at Point 4 (location see Figure 1);
winds 10m sec-1 from NW
Figure 10 Currents at Point 5 (location see Figure 1)
winds 10m sec"1 from NW
Figure 11 Currents at Point 6 (location see Figure 1)
winds 10m sec"1 from NW
0 20 40 60 80
-
cm/sec
- 18 -
-------
Figure 12
Currents at Point 7 (location see Figure 1)
winds 10m sec"1 from NW
Figure 13
Currents at Point 8 (location see Figure 1)
winde 10m sec"1 from NW
Figure 14
Currents at Point 9 (location see Figure 1)
winds 10m sec"1 from NW
0
20
40
cm/sec
60
I
80
- 19 -
-------
Figure 15
Currents at Point 10 (location see Figure 1);
winds 10m sec~l from NW
Figure 16 Currents at Point 11 (location see Figure 1);
winds 10m sec~l from NW
0 20 40 60 80
I ' 1 '
cm/sec
- 20 -
-------
40°30' 7«'l5' 74°10' 40°35' 74°05 ' 74°00'
mwM
w.aum
ma
S S Sfcs
S is a
74*15'
40TM'
74*10'
4Cft»S'
73°55'
40°30'
74*05' 74*00 ' 40*25' 73"55'
Figure 17 Concentrations after 1 hour from instantaneous release (10,000 units)
-------
40°30 74°15' 7410 4035 7405 74°00
74°15'
40°«
74°10'
74°05'
Figure 18
74°00' 402 5 73°55'
Concentrations after 7 hours frcm instantaneous release (10,000 units)
40^35'
73°55'
40 30'
-------
40 30 74*15 74°10' 4035 74°05' 74°00'
74°10'
40°25'
40'35'
73°55'
74*05'
Figure 19
74°00' 4 0°2 5' 73° 55'
Concentrations after 13 hours frcm instantaneous release (10,000 units)
40°30'
-------
40°30' 74°15' 74°10 40°35' 74°05 74°00'
20
30
45
35
50
55
65
45
45
40
40
50
35
ido
30
30
40°25
50
56
25
4Cf35'
73°55'
3 0
20
15
] x POSITION OF RELEASE
74°10'
65
60
50
55
35
30
30
10
35
45
40
40 30
74°00'
Figure 20 Concentrations after 19 hours frcm instantaneous release (10,000 units)
-------
4030' 74°15' 74°10 40°35' 74°05' 74°00'
74*10'
4tf35'
73°55'
74°15'
4CTM'
74°05'
Figure 21
74°00' 40°2S' 73°S5'
Concentrations after 25 hours frcm instantaneous release (10,000 units)
40°30'
-------
4040
74° 10
40 50 74°00'
/J 0J
73°40
| a
liitint
oniliji
40°40'
r4 00
73 OS
40 20 73 40
73 30 40 30
73 20
Figure 22
Computational grid (medium) for Approaches to
New York Bight with indication of locations
of special points and sections
-------
200
Sandy Hook
100
6
a
>
«
in
-100
ru
— — Harmonic
-200
Computed (HN model)
5 10 15 20 25 30
Time, hours
Figure 23 Sea level changes (tides) at Sandy Jlook
as computed with HN model and compared to
harmonic predictions
-------
200
Ft. Ha m i I ton
100
E
o,
U
>
©
ffl -100
Harmonic
-2 00 J
Computed (HNmodel)
Figure 24
10
15
Time, hours
20
25
Sea level changes (tides) at Ft. Hamilton
as computed with HN model and compared to
harmonic predictions
30
-------
200
100
ro
o
M -100
-200
12 16
Figure 25
N
-0 TO 10
10 TO 20
10 TO 30
30 TO 40
40 TO 30
20 24 28 32 36
TIME (Honrs)
Sea level and currents at Point 1 (location
see Figure 22)
-------
20C
100
E
w
uj 0
UJ
O
c/>
-100
-200
1 2
16
Figure 26
-0 TO 10
—»• 10 TO 20
70 TO 30
30 TO 40
_| 40 TO 50
— > JO
20 24 28 32 36
TIME (Hours)
Sea level and currents at Point 6 (locatioh
see Figure 22)
-------
200 H
I
lu
100
«
v.
t*j o
-100
-200
t
12
16
Figure 27
N
-0 TO 10
10 TO 20
20 TO 30
30 TO 40
40 TO 50
—^ > 30
20 24
TIME (Honrs)
28
32
36
Sea level and currents at Point 8 (location
see Figure 22)
-------
N
200
100
OJ
ro
M
-100
-200
10 TO ?0
-.20 TO 30
r- 30 TO 40
<0 TO 30
Figure 28
TIME(Hours)
Sea level and currents at Point 11 (location
see Figure 22)
-------
200
100
w ®
ijj
Ul
M
100
-200
12 16
Figure 29
N
0 TO 10
.'0 TO 20
70 TO 30
30 TO 40
40 TO 55
20 24 28 32 36
TIME (Hoars)
Sea level and currents at Point 12 (location
see Figure 22)
-------
N
200
100-
E
o
0-
Ui
Ui
UJ
-100-
30 IO 40
-200
32
36
12
16
24
28
20
TIME (Hours )
Figure 30
Sea level and currents at Point 13 (location
see Figure 22)
-------
200-
100
Ui
m
V* -100
-200-
12 16
Figure 31
-0 TO 10
10 TO 20
70 TO 30
30 TO 40
40 TO SO
20 24 28 32 36
TIME (Hoars)
Sea level and currents at Point 14 (location
see Figure 22)
-------
40°40
74 ° 10
74°00 40°50
73°50
w
o
40°30
74°10
43°20
74°00
\
7 3 30 40°30
73 50
43 20 73°40
Figure 32
73°40
73°30
40°50
40°40
Currents during high water at Sandy Hook
-------
40°40
74°10
74°00 40°50
73°50
w
40°30
74°10
43°20
74°00
11
* v
i %
t ^
* *
X *
1/ 1 *
%
> / /
* * • 7.
* "
* *
~ ~ ~
« * » *
« •
-------
40°40
74°10
74°00 40°50
73 °50
40°30
4 ft * Ik
0 50 100 150
* | |
cm/sec
7.4° 00
43° 20
7 4 ° 0 0
* « * «
\
\ X ^
A V \
\
\
\
\ \
73°50
Figure 34
43 °20 73°40 73 °30 40°30
Currents 2 hours before low water at Sandy Hook
-------
40°40 74°10
74°00 40°50
73°50
40°30
40 30
74°00
73°50
43°20 73 °40
73 °30 40 °30
Figure 35
Currents during low water at Sandy Hook
-------
Figure 36
Tidal currents at high water at Sandy Hook
(after Marmer, 1935)
- 40 -
-------
Tidal currents at low water at Sandy Hook
(after Marnier, 1935)
-------
HN Model
N.Y., Medium Grid
Grid Point 12,31
Current computed
with HN Model
(Spring tide)
SCOTLAND Lightship
[40 26.6N 73 55.2W)
Mean tidal currents
(Marmer, 1935)
Figure 38
Comparison of currents at or near the
position of Scotland Lightship. A currents
computed with HN model (spring tides) at
grid point 12,31; B mean tidal currents at
Scotland Lightship (40°26.o'N, 73°55.2'W)
(from Marmer, 1935)
20 40
'
cm/sec
- 42 -
-------
Figure 39
Computed currents at Point 7 (location see
Figure 24)
Figure 40
Computed currents at Point 11 (location see
Figure 24)
Figure 41
Computed currents at Point 12 (location see
Figure 24)
20
40
cm/sec
- 43 -
-------
Figure 42 Computed currents at Point 13 (location see
Figure 24)
Figure 43 Computed currents at Point 14 (location see
Figure 24)
0 20 40
¦
cm/sec
- 44 -
-------
40°30'
U1
4020
74'10
40 40
74 10
40 SO 74 00
74*05'
/3 40
m
73 30
4050
73 20
40 40
74 00
74*05'
Figure 44
40 70 73 40 73 30 40 30
Rest currents after a full tidal cycle
7 3 20
-------
Figure 45
AA1
10 15 20 25
TIME, Hours
Transport of water through section AA1
in per second
-------
X
CO
BB2
5 10 15 20 25
TIME, Hours
Figure 46 Transport of water through section BB2
in n»3 per second
-------
100
o
O)
i/9
CO
CC3
20
10
15
TIME, Hours
Figure 47
Transport of water through section CC3
in m3 per second
-------
A
o
u
a»
Figure 48
10
15
20
25
TIME, Hours
Transport of water through section DD4
in in-* per second
-------
40 40
74 10
40 50 74 00
73°05
73'40
il
??iii
X POSITION OF RELEASE
¦
&
—«.
40
35
30
25
74°00
73°05
40 20
73 40
73 30 40 30
73°20
Figure 49 Carputed distribution of "pollutants" after 7 hcurs from release (instantaneous
release 10,000 units, continuous release 360 units per hour)
-------
40 40 74° 10' 40 SO 74°00 73°50 73 40
I
Ln
i
40°30
40°20
7330
40 50
73 20
40 40
74 00 73°05 40 20 73 40 73 30 40 30 73 20
Figure 50 Caiputed distribution of "pollutants" after 17 hours frcm release (instantaneous
release 10,000 units, continuous release 360 units per hour)
------- |