The density anomaly from my output history file is always in the range of 25-45. If this is normal for ROMS file then can anybody tell me how to convert it to normal potential density (sigma-t or sigma-0 in the range of 23-28)?
Thanks,
Qian
question about density anomaly
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ocean_qian
- Posts: 1
- Joined: Sun Aug 19, 2007 1:42 pm
- Location: Scripps Institution of Oceanography
ROMS outputs in situ density (anomaly) because this is the quantity that is integrated vertically to obtain pressure via the hydrostatic relation.
Density is not a state variable of the model, so there is no real need to work in terms of potential density (ROMS does not advect or diffuse density as such, so a conservative density quantity is not required for any computation).
ROMS state variables are salinity and potential temperature, and by equating depth with pressure in decibars you can use one of many possible codes to compute potential density from S and T. See for example options at http://sam.ucsd.edu/sio210/propseawater/ppsw.html
Density is not a state variable of the model, so there is no real need to work in terms of potential density (ROMS does not advect or diffuse density as such, so a conservative density quantity is not required for any computation).
ROMS state variables are salinity and potential temperature, and by equating depth with pressure in decibars you can use one of many possible codes to compute potential density from S and T. See for example options at http://sam.ucsd.edu/sio210/propseawater/ppsw.html
John Wilkin: DMCS Rutgers University
71 Dudley Rd, New Brunswick, NJ 08901-8521, USA. ph: 609-630-0559 jwilkin@rutgers.edu
71 Dudley Rd, New Brunswick, NJ 08901-8521, USA. ph: 609-630-0559 jwilkin@rutgers.edu