Re: [ferret_users] geostrophic currents

[Xavier Couvelard <xavier.couvelard@xxxxxxxxxxxxx>]

HI,
You may should use dynamic_height.jnl that compute dynamic height and 
geostrophic current with T and S given.

yes? go dynamic_height.jnl
cancel mode verify      ! defining dynamic height terms
*** INSTRUCTIONS:
1) Use LET to define three variables:
dyn_S   -   your salinity          (PPT/1000 - 1)
dyn_T   -   your temperature       (degrees C)
dyn_P   -   your pressure          (millibars) (or depth in meters)
note: if you use "Z" for pressure use the G= syntax e.g. Z[G=TEMP]
so that FERRET knows which Z axis to use


2) Use the SET REGION command to specify the depth of zero motion
e.g. SET REGION/Z=0:1000 to set 1000 meters as the zero motion depth


3) Results will be available as the following LET variables:
Result                         XY plane    XZ or YZ plane
---------                      --------    --------------
Dynamic height (dynamic cm)     DYN_HT        DYN_HTz
Geostriphic velocity(cm/sec)  GEO_U,GEO_V   GEO_Uz,GEO_Vz

4) Examples: yes? CONTOUR/X=160e:160w/y=10s:10n DYN_HT   <-- in the XY plane
or           yes? CONTOUR/X=180/Y=10S:10n DYN_HTz        <-- in the YZ plane
The difference in dynamic height between two depths (pressure levels)
may be expressed as e.g. z=500m to 1000m --> DYN_HT[Z=500:1000]

Xavier

golla nageswararao a écrit :

> Hi all,
>    I had used  the geostrophic  currents  jnl file in the mail 
> archives and had plotted the geostrophic currents using default 
> levitus climatology. But i am getting very high meridional component 
> in the order of thousands. But i am getting zonal component in the 
> order of 0.23 like that. I am plotting for indian ocean region. Why 
> such high values are coming for meridional component ? Eventhough when 
> i chang the datasets i am getting the same problem. why it is coming 
> like that?
> Please clear my doubt regarding this computation.
> Thanks in advance.
>
>
> /From,/
>
>     /G.Nageswara Rao,/
>     /Research Scholar,/
>     /INCOIS,/
>     /Jeeidmetla,/
>     /Hyderabad./
>
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