<br><br><div class="gmail_quote">On Mon, Feb 16, 2009 at 10:08 PM, Isaac Tetteh <span dir="ltr"><<a href="mailto:itetteh@ncsu.edu">itetteh@ncsu.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi Arlindo,<br>
Please I'm currently using Win 32 Superpack/Grads v1.9.0-rc 1.<br>
I'm using global NCEP/NCAR reanalysis data, which are at multiple pressure<br>
levels. These are available at<br>
<a href="http://www.cdc.noaa.gov/data/gridded/data.ncep.reanalysis.derived.pressure.html" target="_blank">http://www.cdc.noaa.gov/data/gridded/data.ncep.reanalysis.derived.pressure.html</a>.<br>
I have subset the data to my domain of interest eg -50 90 lon, -40 40 lat.<br>
Even for the moisture budget, I need to further narrow down my domain<br>
further to quantify the moisture in the area of interest to reflect the<br>
focus of my analysis.<br>
If you need further clarification, I will be happy to let you know you.</blockquote><div><br>That is the problem: in order to compute streamfunction fish() uses a global poisson solver; it does not work with anything that is not global. Although you can implement poisson solvers for a local domain, in this case you have to specify boundary conditions --- something that is not easy to properly specify. You can find in the literature variational algorithms for computing streamfunction from (u,v) on a regional domain, but we do not have this implemented yet. If you are incline to develop this, I'm sure it would be very welcome by the community. I understand the algorithm, I just do not have the time to code it right now. For your problem, though, it may be simpler to compute chi/psi in the global domain, and then subset to your domain of interest.<br>
<br> Arlindo<br> </div></div><br clear="all"><br>-- <br>Arlindo da Silva<br><a href="mailto:dasilva@alum.mit.edu">dasilva@alum.mit.edu</a><br>