vertical sections and orography

Davide Sacchetti davide.sacchetti at ARPAL.ORG
Wed Apr 12 05:25:08 EDT 2006


if your plot has pressure as Y coord, I normally plot the surface
pressure [eg: sp=MSLP*exp(-9.81*oro/(287*(t2-0.0065/2*oro)))]
display your cross section var and after display the orography height
['d sp-100*lev' ]

hoping it helps ...
bye bye
Davide

On Tue, 2006-04-11 at 12:12 -0300, Mateus Teixeira wrote:
> I solve this problem by making a 3D binary file making the difference
> between pressure levels and surface pressure.
> I send a F90 program that makes this work, along with the surface
> pressure data as a example!
> Inside it, there are some comments about its functioning.
>
> Thanks to everybody!
> Mateus
>
>
> Arindam Chakraborty a écrit :
> > hi Mateus,
> >         you need to have height (say geopotential) at all levels. Please
> > define orography as a multilevel variable in the gs file before
> > proceeding. All levels of this new variable should have the same value
> > (the value of the orographic height at that location). Then use the
> > maskout function with the geopotential height to maskout levels where
> > geopotential height is less than the orographic height.
> >
> > Hope this helps.
> >
> > arindam
> > ----------------------------
> >  ARINDAM CHAKRABORTY
> >  Department of Meteorology
> >  Florida State University
> >  Tallahassee, FL-32306, USA
> >  Tel: +001-850-6443524 (Off)
> >       +001-850-5758550 (Res)
> >  Fax: +001-850-6449642
> > ____________________________
> >
> > On Thu, 6 Apr 2006, Mateus Teixeira wrote:
> >
> >
> >> Dear GrADS users,
> >>
> >> I'm trying to make some vertical sections and including the orography on
> >> that. I saw the older messages but I any works!
> >> Could someone explain how can I make it?
> >>
> >> Thank you
> >>
> >> Mateus
> >>
> >>
> >>
> >> _______________________________________________________
> >> Abra sua conta no Yahoo! Mail: 1GB de espaço, alertas de e-mail no celular e anti-spam realmente eficaz.
> >> http://br.info.mail.yahoo.com/
> >>
> >>
> >
> >
>
> plain text document attachment (orografia.f90)
> ! ------------------------------------------------------------------------
> ! Program that creates a 3D file with information about orography height.
> ! Useful to depict orography in vertical sections.
> !
> ! File needed: gridded data with pressure surface information.
> !
> ! If this information is not in a normal binary file (e.g., netCDF, GRIB or other
> ! kind of data file) you may use GrADS itself to convert it. You may do this with the
> ! fwrite option for set gxout command, like this:
> !
> !    set gxout fwrite
> !    set fwrite output.bin
> !    set lat ...     |- if necessary.
> !    set lon ...     |
> !    display pressure_surface
> !    disable fwrite
> !
> ! For this you must have a file with same levels and horizontal resolution of the
> ! data file that you want to obtain vertical profiles.
> ! Below is a fragment of GrADS script that plots the orography:
> !
> !    set lat -30
> !    set lon 280 330
> !    set lev 1000 300
> !    ....
> !    <plot your fields here>
> !    ....
> !    set clab off
> !    set cint 5
> !    set cthick 20
> !    set cmax 0
> !    set ccolor 1
> !    d orog(t=1)
> !
> ! As you probably open other files along with orography you have to put
> ! the appropriate number for variable orog. The t=1 prevents problems
> ! related with difference in times of the files.
> !
> ! Mateus da Silva Teixeira.
> ! April / 2006
> ! ----------------------------------------------------------------------------
> program orography
> implicit none
>
> ! Required information for CTL file
> integer, parameter :: xx=25,yy=13,zz=8 ! file dimensions
> integer :: levs(8)=(/1000,925,850,700,600,500,400,300/) ! vertical levels
> real :: rx=2.5,ry=2.5,ilat=-40.,ilon=270    ! horizontal resolution and lat,lon initial
>
> ! Variables
> integer :: lev=1,i,j,k
> real :: psfc(xx,yy),oro(xx,yy)
>
> ! Opening files
> open(28,file='orog.ctl',status='unknown')
> open(29,file='orog.bin',status='unknown',access='direct',form='unformatted',recl=xx*yy)
> open(30,file='psfc.bin',status='old',access='direct',form='unformatted',recl=xx*yy)
>
> read(30,rec=1) psfc ! Reading surface pressure data
>
> do k=1,8
>    do j=1,13
>       do i=1,25
>          oro(i,j)=-levs(k)+psfc(i,j)   ! Calculation of orography elevation
>       end do
>    end do
>    write(29,rec=lev) oro
>    lev=lev+1
> end do
>
> ! Creating CTL file
> write(28,'(A14)') 'DSET ^orog.bin'
> write(28,'(A15)') 'TITLE Orography'
> write(28,'(A15)') 'UNDEF -9.99e+33'
> write(28,'(A4,1X,I2,1X,A6,1X,F5.1,1X,F3.1)') 'XDEF',xx,'LINEAR',ilon,rx
> write(28,'(A4,1X,I2,1X,A6,1X,F5.1,1X,F3.1)') 'YDEF',yy,'LINEAR',ilat,ry
> write(28,'(A4,1X,I2,1X,A6,1X,8I5)') 'ZDEF',zz,'LEVELS',(levs(i),i=1,zz)
> write(28,'(A31)') 'TDEF 1  LINEAR 16Z06APR2006 1DY'
> write(28,'(A6)') 'VARS 1'
> write(28,'(A4,1X,I2,1X,A12)') 'orog',zz,'99 Orografia'
> write(28,'(A7)') 'ENDVARS'
>
> end program orography
>
--
Sacchetti Davide
ARPAL UO3 Centro Meteo Idrologico Regione Liguria - Dir. Scientifica
P.za Vittoria 15 16121 Genova (I)
tel: +39 010 6437535
mail: davide.sacchetti at arpal.org   web: www.meteoliguria.it



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