RE: ageostrophic component from operational (u,v) fwind ields

• To: "HansPeter Roesli" <satmet.hp@xxxxxxxxxx>
• Subject: RE: ageostrophic component from operational (u,v) fwind ields
• From: "Fingerhut, William A @ LSC" <William.Fingerhut@xxxxxxxxxxx>
• Date: Fri, 8 Dec 2006 10:44:07 -0500

_From William.Fingerhut@xxxxxxxxxxx  Fri Dec  8 08:44:15 2006
Received: from lsc.vsc.edu (email.lsc.vsc.edu [155.42.122.21])
        by unidata.ucar.edu (UCAR/Unidata) with ESMTP id kB8FiEXX013963
        for <owner-idvusers@xxxxxxxxxxxxxxxx>; Fri, 8 Dec 2006 08:44:15 -0700 
(MST)
Organization: UCAR/Unidata
Keywords: 200612081544.kB8FiEXX013963
References:  <45788800.7000901@xxxxxxxxxx>
In-Reply-To:  <45788800.7000901@xxxxxxxxxx>
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: multipart/alternative;
        boundary="----_=_NextPart_001_01C71ADF.B2912CA9"
Thread-Topic: ageostrophic component from operational (u,v) fwind ields
Thread-Index: AccaSgj/MYLSl3GkQrW8sCxCk9KW5wAkmLeQ
Cc: <owner-idvusers@xxxxxxxxxxxxxxxx>
X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on 
        laraine.unidata.ucar.edu
X-Spam-Level: 
X-Spam-Status: No, score=-2.5 required=5.0 tests=AWL,BAYES_00,HTML_MESSAGE 
        autolearn=ham version=3.0.1

This is a multi-part message in MIME format.

------_=_NextPart_001_01C71ADF.B2912CA9
Content-Type: text/plain;
        charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

I have a cludgy jython method that computes geostrophic wind,
which one could easily modify or 'use' to compute the ageostrophic wind.

To use it, I first select a dataset (model data);=20

then use a formula: geoWind(height_grid)

which uses the jython method:


#
# geostrophic wind
#
def geoWind(h):
  from ucar.unidata.data.grid.DerivedGridFactory import *
  z=3D0.*h
  o=3Dz-1
  vg=3D100.*DerivedGridFactory.createHorizontalAdvection(h,o,z)
  ug=3D-100.*DerivedGridFactory.createHorizontalAdvection(h,z,o)
  return DerivedGridFactory.createTrueWindVectors(ug,vg)


The constant 100 includes the correct constant for the geostrophic wind,
a constant latitude, and a scaling factor. The constants, 0 and 1, allow
me
to use the existing code to calculate each partial derivative of height.

If anyone has another method, I would like to hear about it.

Bill

< Bill Fingerhut, Professor           PHONE: 802-626-6257 >
< Meteorology Dept                    FAX:   802-626-9770 >
< Lyndon State College                                    >
< Lyndonville, Vt 05851                                   >
<                                                         >
< EMAIL:     william.fingerhut@xxxxxxxxxxxxxxx            >
<            bfingerhut@xxxxxxxxxxxxxxxx                  >
< WWW:       http://apollo.lsc.vsc.edu/ <http://apollo.lsc.vsc.edu/>
>
<                                                         >
< disclaimer: I know nothing - I only work here.          >


> -----Original Message-----
> From: owner-idvusers@xxxxxxxxxxxxxxxx
> [mailto:owner-idvusers@xxxxxxxxxxxxxxxx
<mailto:owner-idvusers@xxxxxxxxxxxxxxxx> ] On Behalf Of HansPeter Roesli
> Sent: Thursday, December 07, 2006 4:31 PM
> To: IDV Users' Mailing List
> Subject: ageostrophic component from operational (u,v) fwind ields
>
>
> Hi all
>
> I would like to draw flow fields of the ageostrophic component of
> numerical (u,v) wind fields. Anybody out there who has already
> implemented this in some way. I would be very grateful in
> receiving some
> information.
>
> HansPeter Roesli
> consultant to EUMETSAT in satellite meteorology
>


------_=_NextPart_001_01C71ADF.B2912CA9

• Follow-Ups:
  • RE: ageostrophic component from operational (u,v) wind fields
    • From: Don Murray