Units of Precipitation,U,V wind etc. in ERA 40 datasets

Fri Nov 10 17:30:17 EST 2006

Divide by 9.8 (gravity) and not by 10...

On 11/10/06, NASER SARHAN <meet100 at yahoo.com> wrote:
>
> u         21 99 u wind (m/s)
> v         21 99 v wind (m/s)
> z        21 99 geopot height (m**2/s**2)   you have to divide by 10 when
> drawing z to be m/s**2
> t         21 99 temperature (K)
>
>
>
> sajjad saeed <sajjad_met at HOTMAIL.COM> wrote:
> Dear Bernd Becker,
>
> The units are not given on that page and on the related links. Can you tell
> me what is the unit of precipitation in ERA 40 datasets. Is precipitation
> expressed in mm/day or cm/day etc for the daily data? Likewise what are the
> units of U and V components of wind, Is it expressed in m/see or cm/see etc.
> Where from I can get such information
>
> Thankyou for your early response
>
> Sajjad
>
>
>
> ******************************************************************************
> Sajjad Saeed
> Meteorologist,
> Pakistan Meteorological Department (PMD),
> P.O.Box 1214, Sector H-8/2, Islamabad, Pakistan.
>
> Research Fellow,
> Global Change Impact Studies Centre (GCISC),
> First Floor, Saudi Pak Tower, Blue Area, Islamabad, Pakistan.
> Ph: +92-51-9219785, Fax: +92-51-9219787
> Mob:+92-334-5419962
> Email: sajjad_met at hotmail.com. sajjad2pk2 at yahoo.com
> sajjad.saeed at gcisc.org.pk
>
>
>
>
>
> >From: bernd.becker at METOFFICE.GOV.UK
> >Reply-To: GRADSUSR at LIST.CINECA.IT
> >To: GRADSUSR at LIST.CINECA.IT
> >Subject: Re: Units of Precipitation,U,V wind etc. in ERA 40 datasets
> >Date: Fri, 10 Nov 2006 11:34:29 +0000
> >
> >http://www.ecmwf.int/products/data/archive/descriptions/e4/index.html
> >
> >On Fri, 2006-11-10 at 16:29 +0500, sajjad saeed wrote:
> > > Dear all,
> > >
> > > Can some one tell me what are the units of precipitation, u, v wind,
> > > temperature etc in the reanalysis ERA 40 datasets of ECMWF. From where
> >we
> > > can find the units of different variables available in ERA 40 datasets.
> > >
> > > Thanyou in advance for your information.
> > >
> > >
> > > Sajjad Saeed
> > >
> ...........................................................
> > > Meteorologist,
> > > Pakistan Meteorological Department (PMD),
> > > P.O.Box 1214, Sector H-8/2, Islamabad, Pakistan.
> > >
> > > Research Fellow
> > > Global Change Impact Studies Centre (GCISC),
> > > First Floor, Saudi Pak Tower, Blue Area, Islamabad, Pakistan.
> > > Ph: +92-51-9219785, Fax: +92-51-9219787
> > > Mob:+92-334-5419962
> > > Email: sajjad_met at hotmail.com. sajjad2pk2 at yahoo.com
> > > sajjad.saeed at gcisc.org.pk
> > >
> > >
> > >
> > >
> > >
> > > >From: Suvarna Fadnavis
> > > >Reply-To: GRADSUSR at LIST.CINECA.IT
> > > >To: GRADSUSR at LIST.CINECA.IT
> > > >Subject: Re: contour plot for diff latitudinal belts
> > > >Date: Wed, 28 Jun 2006 07:03:35 +1200
> > > >
> > > >Dear Dr. ARINDAM CHAKRABORTY,
> > > > Thank you for your help in plotting contour in proper oredr( x,y, z
> >and
> > > >t).
> > > > with best regards
> > > > Suvarna
> > > >On Fri, 23 Jun 2006 22:17:34 -0400, Arindam Chakraborty wrote
> > > > > hi Suvarna,
> > > > > when grads reads a data file, (by default) the different
> > > > > dimensions are read in this order: x, y, z, variable, t;
> > > > > Means x (longitude) varies fastest, and then y (latitude) and so on.
> > > > > (Although there can be variations of this, see
> > > > >
> http://grads.iges.org/grads/gadoc/descriptorfile.html#VARS
> for
> > > > > 'non-standard binaries' for details. But for your control file the
> > > > > standard rule applies).
> > > > > Now, one of your control files has y and z, for which first
> >8
> > > > > data values in the file will be read as different latitudes at the
> > > > > first level, and so on. For another control file, which has z and t,
> > > > > the first 12 data values will be taken as different levels at the
> > > > > first latitude (alias time here), and so on for the rest of
> > > > > the data. This is the reason you get different results for those two
> > > > > control files.
> > > > > How to write the control file is dependent on how you've
> > > > > written down the data file. It is always a good idea to write the
> >data
> > > > > in the default order of grads if you plan to use it in grads later
> >on.
> > > > > In your case, you need to write y as the faster varying dimension
> > > > > than z in your output data file. Then use the control file which has
> >y
> > > > > and z.
> > > > > Please also set the lat levels as 35, 25, ..., 5, -5, ...,
> >35
> > > > > (the centers of the bands of average), that's a better way of
> > > > > representation.
> > > > >
> > > > > ----------------------------
> > > > > 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 Sat, 24 Jun 2006, Suvarna Fadnavis wrote:
> > > > >
> > > > > > Dear Dr. Chakraborty,
> > > > > > I am trying to plot (Contor) QBO values obtaied at 8
> > > >latitudinal belts
> > > >(40-
> > > > > > 30, 30-20, 20-10, 0-10 10-0 10-20, 20-30, 30-40). I want to plot
> >QBO
> > > >values by
> > > >taking
> > > > > > x axis as latitude and y axais as pressure levels. I tried to plot
> >it
> > > >by taking
> > > > > > (1) x-axis as time (t=8) and y -axis as pressure
> > > > > > (2) x-axis as latitude and y -axis as pressure by defining ydef 8
> > > >levels -40 -30 -
> > > >20 -
> > > > > > 10 10 20 30 40
> > > > > > I should get the same structure but I get two
> >different
> > > >structure.
> > > >Please
> > > > > > guide me which is correct and what is the reason for difference. I
> >am
> > > >attaching ctl
> > > >and
> > > > > > gs and data file for your kinf perusal.
> > > > > > suvarna
> > > >
> > > >
> > > >With best regards
> > > > Suvarna Fadanvis
> > > >Scientist –B
> > > >Indian Institute Of Tropical Meteorology
> > > >DR. Homi Bhabha road, Pashan, Pune, India
> > > >Ph. No 25893600
> > >
> > >
> _________________________________________________________________
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> >--
> >Bernd Becker The Monthly Outlook
> >Met Office FitzRoy Road Exeter Devon EX1 3PB United Kingdom
> >Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050
> >E-mail:bernd.becker at metoffice.gov.uk - http://www.metoffice.gov.uk
>
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>
>
> Kind Regards
> Naser Sarhan
> School of Environmental Sciences
> University of East Anglia
> Norwich NR4 7TJ
>
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