[MITgcm-support] Guide to output variables?

[Christopher L. Wolfe]

Thanks for the information on the variables. Also, thanks for pointing 
me to the beta version of the manual. It seems much more complete than 
the PDF version I downloaded with the code.

Cheers,
Christopher

-----------------------------------------------------------
Dr. Christopher L. Wolfe             		 858-534-4560
Physical Oceanography Research Division    OAR 357
Scripps Institute of Oceanography, UCSD    clwolfe at ucsd.edu
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On Nov 6, 2006, at 12:06 PM, Baylor Fox-Kemper wrote:

> Hi Chris:
> Dmitris is right, check out model/inc/GRID.h, but here goes my take:
>> XC.*X coordinate a centered (e.g., temp, salt, pressure) points
>> XG.*X coordinate on grid (i.e., where U velocities and zonal fluxes 
>> are)
>> PH.*PhiHyd: Flow Potential::: Different depending on whether you're 
>> atmospheric or oceanic:::
> C     phiHydC    :: hydrostatic potential anomaly at cell center
> C                   In z coords phiHyd is the hydrostatic potential
> C                      (=pressure/rho0) anomaly
> C                   In p coords phiHyd is the geopotential height 
> anomaly.PHL.*PhiHydLow: different estimate of PhiHyd
>> RAC.*area of cell center:  1/diff(XC)/diff(YC)
>> RAS.*area of 'south' point: 1/diff(XC)/diff(YG)
>> RAW.*area of 'west' point: 1/diff(XG)/diff(YC)
>> RAZ.*area of vorticity (zeta) point: 1/diff(XG)/diff(YG)
>
> The notation is crummy, I agree.  But, Ed is right, mnc does give you 
> some hints.  Here is an ncdump from a typical grid.001.nc file, which 
> gives you 'long names' for these variables.
>
>  double Z(Z) ;
>       double RC(Z) ;
>               RC:description = "R coordinate of cell center" ;
>          RC:units = "m" ;
>      double Zp1(Zp1) ;
>       double RF(Zp1) ;
>               RF:description = "R coordinate of cell interface" ;
>          RF:units = "m" ;
>      double Zu(Zu) ;
>       double RU(Zu) ;
>               RU:description = "R coordinate of upper interface" ;
>          RU:units = "m" ;
>      double Zl(Zl) ;
>       double RL(Zl) ;
>               RL:description = "R coordinate of lower interface" ;
>          RL:units = "m" ;
>      double drC(Z) ;
>               drC:description = "r cell center separation" ;
>   double drF(Z) ;
>               drF:description = "r cell face separation" ;
>   double X(X) ;
>       double Y(Y) ;
>       double XC(Y, X) ;
>              XC:description = "X coordinate of cell center (T-P 
> point)" ;
>                XC:units = "degree_east" ;
>      double YC(Y, X) ;
>              YC:description = "Y coordinate of cell center (T-P 
> point)" ;
>                YC:units = "degree_north" ;
>      double Xp1(Xp1) ;
>       double Yp1(Yp1) ;
>       double XG(Yp1, Xp1) ;
>              XG:description = "X coordinate of cell corner (Vorticity 
> point)" ;
>                XG:units = "degree_east" ;
>      double YG(Yp1, Xp1) ;
>              YG:description = "Y coordinate of cell corner (Vorticity 
> point)" ;
>                YG:units = "degree_north" ;
>      double dxC(Y, Xp1) ;
>              dxC:description = "x cell center separation" ;
>   double dyC(Yp1, X) ;
>              dyC:description = "y cell center separation" ;
>   double dxF(Y, X) ;
>              dxF:description = "x cell face separation" ;
>   double dyF(Y, X) ;
>              dyF:description = "y cell face separation" ;
>   double dxG(Yp1, X) ;
>              dxG:description = "x cell corner separation" ;
>   double dyG(Y, Xp1) ;
>              dyG:description = "y cell corner separation" ;
>   double dxV(Yp1, Xp1) ;
>              dxV:description = "x v-velocity separation" ;
>    double dyU(Yp1, Xp1) ;
>              dyU:description = "y u-velocity separation" ;
>    double rA(Y, X) ;
>              rA:description = "r-face area at cell center" ;
>  double rAw(Y, Xp1) ;
>              rAw:description = "r-face area at U point" ;
>  double rAs(Yp1, X) ;
>              rAs:description = "r-face area at V point" ;
>  double rAz(Yp1, Xp1) ;
>              rAz:description = "r-face area at cell corner" ;
>  double fCori(Y, X) ;
>              fCori:description = "Coriolis f at cell center" ;
>  double fCoriG(Yp1, Xp1) ;
>              fCoriG:description = "Coriolis f at cell corner" ;
>  double R_low(Y, X) ;
>              R_low:description = "base of fluid in r-units" ;
>  double Ro_surf(Y, X) ;
>              Ro_surf:description = "surface reference (at rest) 
> position" ;
>  double Depth(Y, X) ;
>              Depth:description = "fluid thickness in r coordinates (at 
> rest)" ;
>        double HFacC(Z, Y, X) ;
>             HFacC:description = "vertical fraction of open cell at 
> cell center" ;
>       double HFacW(Z, Y, Xp1) ;
>             HFacW:description = "vertical fraction of open cell at 
> West face" ;
>       double HFacS(Z, Yp1, X) ;
>             HFacS:description = "vertical fraction of open cell at 
> South face" ;
>
> Hope that helps.  
> -Baylor_______________________________________________
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