The propagation of sound in a density-stratified fluid is examined in an experiment with a tank of salty water whose density increases continuously from the fluid surface to the tank bottom. Measurements of the height dependence of the fluid density are used to calculate the height dependence of the fluid salinity and sound speed. The height-dependent sound speed is then used to calculate the refraction of sound rays. Sound propagation in the fluid is measured in three dimensions and compared with the ray analysis. This study provides a basis for laboratory modeling of underwater sound propagation in the fluctuating stratified oceans.

1.
Robert A.
Frosch
, “
Underwater sound: Deep-ocean propagation
,”
Science
146
(
3646
),
889
894
(
1964
).
2.
W. A.
Kuperman
and
J. F.
Lynch
, “
Shallow-water acoustics
,”
Phys. Today
57
(
10
),
55
61
2004
.
3.
J. R.
Apel
,
L. A.
Ostrovsky
,
Y. A.
Stepanyants
, and
J. F.
Lynch
, “
Internal solitons in the ocean and their effect on underwater sound
,”
J. Acoust. Soc. Am.
121
(
2
),
695
722
(
2007
).
4.
D. J.
Tang
and
Coauthors
, “
Shallow water'06: A joint acoustic propagation/nonlinear internal wave physics experiment
,”
Oceanography
20
,
156
167
(
2007
).
5.
L. K.
Zhang
and
H. L.
Swinney
, “
Virtual seafloor reduces internal wave generation by tidal flow
,”
Phys. Rev. Lett.
112
,
104502
(
2014
).
6.
R. N.
Baer
, “
Calculations of sound propagation through an eddy
,”
J. Acoust. Soc. Am.
67
(
4
),
1180
1185
(
1980
).
7.
Y. J.
Jian
,
J.
Zhang
,
Q. S.
Liu
, and
Y. F.
Wang
, “
Effect of mesoscale eddies on underwater sound propagation
,”
Appl. Acoust.
70
(
3
),
432
440
(
2009
).
8.
W. S.
Holbrook
,
P.
Páramo
,
S.
Pearse
, and
R. W.
Schmitt
, “
Thermohaline fine structure in an oceanographic front from seismic reflection profiling
,”
Science
301
(
5634
),
821
824
(
2003
).
9.
Y.-T.
Lin
and
J. F.
Lynch
, “
Analytical study of the horizontal ducting of sound by an oceanic front over a slope
,”
J. Acoust. Soc. Am.
131
(
1
),
EL1
EL7
(
2012
).
10.
Robert G.
Stone
and
David
Mintzer
, “
Range dependence of acoustic fluctuations in a randomly inhomogeneous medium
,”
J. Acoust. Soc. Am.
34
(
5
),
647
653
(
1962
).
11.
S. J.
Campanella
and
A. G.
Favret
, “
Time autocorrelation of sonic pulses propagated in a random medium
,”
J. Acoust. Soc. Am.
46
(
5B
),
1234
1245
(
1969
).
12.
N. P.
Chotiros
and
B. V.
Smith
, “
Sound amplitude fluctuations due to a temperature microstructure
,”
J. Sound Vib.
64
(
3
),
349
369
(
1979
).
13.
Philippe
Roux
,
Ion
Iturbe
,
Barbara
Nicolas
,
Jean
Virieux
, and
J. I.
Mars
, “
Travel-time tomography in shallow water: Experimental demonstration at an ultrasonic scale
,”
J. Acoust. Soc. Am.
130
(
3
),
1232
1241
(
2011
).
14.
G.
Real
,
D.
Habault
,
X.
Cristol
,
J. P.
Sessarego
, and
D.
Fattaccioli
, “
An ultrasonic testbench for emulating the degradation of sonar performance in fluctuating media
,”
Acta Acust. Acust.
103
(
1
),
6
16
(
2017
).
15.
Guy
Rabau
, “
Scaled tank experiments of low-frequency propagation in the sofar channel
,”
Acta Acust. Acust.
85
(
1
),
12
17
(
1999
).
16.
V. V.
Mitkin
,
V. E.
Prokhorov
, and
Y. D.
Chashechkin
, “
Acoustic sounding of vortex rings in a continuously stratified fluid
,”
Fluid Dyn.
36
(
6
),
934
943
(
2001
).
17.
G.
Oster
, “
Density gradients
,”
Sci. Am.
213
,
70
76
(
1965
).
18.
S. J.
Kleis
and
L. A.
Sanchez
, “
Dependence of speed of sound on salinity and temperature in concentrated NaCl solutions
,”
Sol. Energy
45
(
4
),
201
206
(
1990
).
19.
M.
Laliberté
and
W. E.
Cooper
, “
Model for calculating the density of aqueous electrolyte solutions
,”
J. Chem. Eng. Data
49
(
5
),
1141
1151
(
2004
).
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