Find the LCL / 'define' problem

[Marco Stoll]

Thanks Doug and Wolfgang,

'set defval ....' is exactly what i'm looking for!

Cheers Marco


Douglas Clark wrote:

>Marco,
>
>You can probably do what you want using 'set defval'. This can be used
>to set the value of a 2-D variable at a single point. As it says on
>http://grads.iges.org/grads/gadoc/gadocindex.html:
>
>"set defval var ival jval value
>where:
>
>var    - the 2-D defined variable
>ival   - X coordinate of the grid point
>jval   - Y coordinate of the grid point
>value  - the new value for the variable"
>
>So you could calculate the LCL at each (x,y) point and then set the
>value of the gridded lat/lon variable.
>I've got a feeling that 'set defval' can only change the value at t=1,
>which might limit its use for you, but maybe I'm wrong....
>
>Hope this helps,
>Doug
>
>
>
>>>>stoll at GIUB.UNIBE.CH 09/05/2005 13:27:57 >>>
>>>>
>>>>
>Dear GrADS users,
>
>I try to calculate LCL in my gridded data set (terrain following model
>layers).
>
>My algorithm steps upward from the surface iteratively always one
>level, calculates the thetaE at this level and compares
>with the mixing ratio in order to check, wether LCL is reached or not.
>
>This works fine for one single gridpoint, but how can I find
>the LCL's over the whole domain? Since, it is reached at
>different vertical levels, I cannot just do the calculation
>with the whole array.....
>
>Is there a way to go through every gridpoint and define
>a single variable 'lcl' dependent on lat/lon?
>
>Thanks in advance for your help and proposals,
>
>Marco
>
>
>===========================================
>Marco Stoll, Student of Geography
>Zaelglistrasse 18
>3202 Frauenkappelen, Switzerland
>
>Institute of Geography, Universtity of Bern
>Climatology/Meteorology Group
>
>email: stoll at giub.unibe.ch
>Phone: 0041 31 920 03 53
>Mobile: 0041 78 759 83 29
>===========================================
>
>
>
>