How to plot sound wave speed in water?

Hi respected experts,

I wanna plot the speed of acoustic waves in water accross the depth.

Here is below the detail:

Acoustic wave speed =1500 m/s

Salinity = 40 partplus (ppt)

Temperature= 30 oC

Depth = 500 m

This is actulay thermocline plot, I tried from 5 days but I am unable to success.

Please help me in this regards!

[tayyaba ilyas]

cant we use plotssp function?

please see the attached file page 11

[Nathan Han]

thanks to the sound profile provided in that pdf, you can just use the following code for plot a fixed sound profile.

To plot a more flexible sound profile, David's answer works great.

depth = [0 200 250 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600 4800 5000];

c_wave = [1548.52 1530.29 1526.69 1517.78 1509.49 1504.3 1501.38 1500.14 1500.12 1501.02 1502.57 1504.62 1507.02 1509.69 1512.55 1515.56 1518.67 1521.85 1525.1 1528.38 1531.7 1535.04 1538.39 1541.76 1545.14 1548.52 1551.91];

figure("position", [20 500 350 400])

plot(c_wave,depth,'k-','linewidth',1.5);

set(gca, 'XAxisLocation', 'top', 'YAxisLocation', 'left', 'YDir', 'reverse','FontSize',12);

xlabel("Speed of sound (m/s)")

ylabel("Depth (m)")

Answer 1

[David Hill]

I simple search finds https://en.wikipedia.org/wiki/Speed_of_sound and gives the simple empirical equation for speed of sound in seawater.

c = 1448.96 + 4.591*T - 5.304e-2*T.^2 + 2.374e-4*T.^3 + 1.340*(S - 35) + 1.630e-2*z + 1.675e-7*z.^2 - 1.025e-2*(S - 35) - 7.139e-13*T.*z.^3;

So if you want to plot c (speed of sound) vs. depth z (in meters) you will need vectors for T (in degrees C) vs. depth and S (salinity in parts per thousand) vs. depth; otherwise, if T and S are held constant, c will be constantly increasing with depth.

Once you have vectors for z, T, and S, you just plug them into the equation to get the vector of c and:

plot(c,z);

[Junaid Qadir]

Can you please plot it for me? I tried too much but failed to plot.

[darova]

6 months without success

David can you elaborate?

[Junaid Qadir]

I also need this plot for the last few months.

[David Hill]

You need to figure out what the temperature is vs depth and what the salinity is vs depth, or provide the speed vs depth vectors. Give me the input and I or someone else can help you produce the plot you desire.

[Junaid Qadir]

Thank you so much for your reply.

Please see following paramters below.

Temperature= 30 Degree Centigrade

Salinity= 40 Part Plus PPT

Depth= 5000 Meters

Speed of Sound = 1449 + 4.591 *T - 5.304 * 10^(-2)*T^(2) + 2.374 * 10^ (-4) * T^(3)

% + 1.34*(S - 35) + 1.63 * 10^(-2) * D + 1.675 * 10^(-7)* D + 1.025* 10^(-2)* T*(S - 35) - 7.139* 10^(-3)*T*D^3;

I need a plot where the Depth is on Y-axis and speed is on a-axis as shown in the above figure.

Request you to please contact me if you need further information

Email: [e-mail]

[george masters]

did you manage to do the plot?

[Junaid Qadir]

@george masters

No still not.

[Darija_S]

Hi! Did you maybe got an answer for this? I'm trying to do it, but it's not going as I want....

[Junaid Qadir]

@Darija_S Try to calculate it from equations given in the paper. I checked the code in my laptop, but I could not find it. If I found the code I must share it with you.

https://ieeexplore.ieee.org/document/9130704