[gradsusr] Moisture flux convergence/divergence

[Roger Rodrigues Torres]

Dear Hyacinth,
are you interested in calculating the "vertically integrated moisture
transport", or the convergence only in one single level?
If you are interested in the firts one, I calculate, for exemple, in the
following manner:

'sdfopen file-pressure.nc'
'sdfopen file-zonal-wind.nc'
'sdfopen file-meridional-wind.nc'
'define QiJAN=ave(vint(prmsl.1(z=1)/100,shum.1*uwnd.2,200),t=1,t=1560,12)'
'define QjJAN=ave(vint(prmsl.1(z=1)/100,shum.1*vwnd.3,200),t=1,t=1560,12)'
'set gxout vector'
'd QiJAN;QjJAN'

Addicionally, if you wish to plot the "vertically integrated moisture flux
convergence"

'define divQ=hdivg(QiJAN,QjJAN)'
'set gxout shaded'
'd divQ'

Cheers,
Roger Torres


2011/9/16 Hyacinth Nnamchi <hyacinth.1 at hotmail.com>

>  Jeff,
>
> I seems my question wasn't well framed, and so you dealt with the typo. I
> have attached two Figs showing what the calculations below will give and
> what exactly I'll like to do.
>
> Thanks,
>
> Hyacinth
>
>
> > Date: Thu, 15 Sep 2011 17:34:50 -0500>
> From: Jeffrey Duda <jdduda at iastate.edu>>
>  Subject: Re: [gradsusr] Moisture flux convergence/divergence
> > To: GrADS Users Forum <gradsusr at gradsusr.org>
> > Message-ID:
> > <CAP9LQ-VNkxcu-+ey_QkZU7f4MHf+VwJDvav=Dci3ns+x+pjG8Q at mail.gmail.com>
> > Content-Type: text/plain; charset="iso-8859-1"
>
> >
> > Set the graphics output to vector ('set gxout vector'), then 'd zon;mer'
> > (note the semicolon instead of a comma).
> >
> > Jeff Duda
> >
> > 2011/9/15 Hyacinth Nnamchi <hyacinth.1 at hotmail.com>
> >
> > > Hello,
> > >
> > > This is not directly about GrADS but since most of address similar!
> > > problems, I guess someone on this forum will be able to answer my
> question.
> > >
> > > I understand that to calculate moisture transport, given zonal,
> meridional
> > > winds and specific humidity, can simply do:
> > >
> > > 'define zon=uwnd.1*shum.3'
> > > 'define mer=vwnd.2*shum.3'
> > > 'd zon,mer'
> > >
> > > But, I want to plot vectors indicating field of net moisture flux (all
> arrows converging/diverging) instead of just transport.
> > >
> > > Thanks for any ideas.
> > >
> > > Hyacinth
> > >
> > >
> > > __
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>


-- 
Roger Rodrigues Torres
PhD. Student in Meteorology
National Institute for Space Research (INPE)
Phone: 55 12 3186-9541
Personal Webpage: http://rtorres.webnode.com.br
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20110916/db280db5/attachment-0003.html