[Mitgcm-support] RE: convective adjustment in the MIT-GCM

[mitgcm-support at dev.mitgcm.org]

Hi Nadia,

  The static stability test is done on a density anomaly ( with a stably
stratified background removed) referenced to a common local depth (the
upper tracer cell center in the two layers). The standard density
calculation uses potential temperature and salinity and applies a depth
dependent EOS formula that accounts for pressure effects due to
overlying fluid mass.

Chris



> -----Original Message-----
> From: ayoub at notos.cst.cnes.fr 
> [mailto:ayoub at notos.cst.cnes.fr] On Behalf Of Nadia Ayoub
> Sent: Tuesday, April 08, 2003 9:36 AM
> To: cnh at ocean.mit.edu; adcroft at mit.edu
> Subject: convective adjustment in the MIT-GCM
> 
> 
> 
>  Hi Chris and Alistair,
> 
> how are you ? 
> I guess you are both of you attending the EGS meeting ... 
> 
> But in case you read your email, I have a question
> concerning the convective adjustment scheme used in the
> MIT-GCM. I am still working with the old GCM but I guess
> the answer to my question will be the same whatever model's
> version is used:
> the convective scheme compares the density between 2 consecutive
> layers and 'mixes' if the density of the lower layer is weaker than
> the density of the upper layer. Right ? So my question is:
> is the comparison made on potential density 'sigma-theta' (i.e. 
> without pressure effects) or on the 'total' density ???
> 
> Thanks in advance !
> Cheers,
> Nadia
> 
> ---
> Nadia Ayoub
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>