Soundspeed for ROMS output

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colberg
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Soundspeed for ROMS output

#1 Post by colberg » Sun Feb 10, 2019 11:39 pm

Hi all,

just wondering if anyone has some code that calculates the soundspeed from ROMS output files ?

Cheers
Frank

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arango
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Re: Soundspeed for ROMS output

#2 Post by arango » Mon Feb 11, 2019 5:12 am

It has been in ROMS plotting package that uses the NCAR's GKS library since the beginning. Check the file src/Utility/svel.F in the plot repository. It uses the Che and Millero (1976) formula.

Chen, C.T. and F.J. Millero, 1976: re-evaluation of Willson sound-speed measurements in pure water. J. Acoust. Soc. of Amer., 60(6), 1270-1273

I am not familiar with the literature of sound speed computation. I bet that there are newer formulations out there.

Also, it will be very trivial to compute from ROMS nonlinear equation of state since it has all the variables that it needs:

Code: Select all

svel2 = ABS(10000.0./(den * gamma))
svel = SQRT(svel2);
where gamma is the adiabatic and isentropic compressibility coefficient (1/Pa).

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wilkin
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Re: Soundspeed for ROMS output

#3 Post by wilkin » Mon Feb 11, 2019 2:31 pm

There is also code in the CSIRO seawater toolbox for Matlab (function sw_svel) though seawater has been superseded by the Gibbs SeaWater (GSW) toolbox for TEOS-10
http://www.teos-10.org/pubs/gsw/html/gsw_contents.html
and in there it is function gsw_sound_speed
John Wilkin: DMCS Rutgers University
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colberg
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Re: Soundspeed for ROMS output

#4 Post by colberg » Mon Feb 11, 2019 10:33 pm

Thanks guys !

Hernan - OK - I remember having problems with compiling the plotting package in the past due to ncarg library. I'll give it another go.

Generally I think it would be nice to decouple the soundspeed calculation from the actual plotting routines and be able to write it into the average or history output files given T and S.

I look into this.

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Re: Soundspeed for ROMS output

#5 Post by arango » Mon Feb 11, 2019 10:34 pm

Just do it in Matlab.

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