[NARCCAP-discuss] Questions on data for our project.

[Lingli He]

Ping:

you also need to register the NARRCAP group to download data, follow the
instruction below:
http://www.narccap.ucar.edu/data/access.html

For NCL language, I usually found the examples at NCL website very helpful:
http://www.ncl.ucar.edu/Applications/

Hope these would help.

Lingli
On Mon, Apr 9, 2012 at 11:24 PM, ping yang <pingyang.whu at gmail.com> wrote:

> Dear Seth,
>
> Thank you so much for the previous advice on data and operations with
> NARCCAP data.
>
> Actually I have question on both the data downloading and data analysis(I
> will be appreciated if you can cover tomorrow)
> 1)I have a user ID and I tried to download the NARCAAP data but without
> success
> 2)I have difficulty in running some scripts that you mentioned for temporal
> aggregation because lack of knowledge in NCL, it will be nice if you can
> provide some information tomorrow
>
> Looking forward to meeting you tomorrow.
>
> Regards,
>
> Ping
>
> On Mon, Mar 12, 2012 at 11:17 PM, Seth McGinnis <mcginnis at ucar.edu> wrote:
>
> > Hi Ping,
> >
> > All the NARCCAP data is 3-hourly, so if you want daily and monthly
> > averages,
> > you'll have to do the averaging yourself.  The only exceptions are the
> four
> > variables in Table 1, which are inherently daily values.  (We do have
> > plans to
> > make a number of monthly and seasonal averages and climatologies
> > available, but
> > they're not ready yet.)
> >
> > If you're an NCL user, I wrote a script ("aggregate.ncl") for creating
> > various
> > time-averages that you may find useful.  You can find it here:
> > http://narccap.ucar.edu/contrib/tools/ncl/  It's also pretty easy to
> > create
> > those time-averages using the NCO command "ncrcat" and the multislab
> > feature.
> >  (Especially if you have NCO installed with udunits support, and can use
> > date
> > ranges for subsetting the time coordinate -- see my post to the
> > narccap-discuss
> > mailing list of about a week ago for more details.)
> >
> > To get the variables that you list, you'll need either to change units or
> > calculate them from other variables, depending. The published data
> > includes:
> >
> > * tas = surface air temperature in degK
> > * pr = precipitation in flux units (kg/m^2/s)
> > * ps = surface air pressure (in Pa)
> > * clt = cloud cover (fraction from 0 to 1 -- look in Table 3 for this
> one)
> >
> > I wrote a couple shellscripts that use NCO commands to change units for
> > temperature and precipitation.  You can find them here:
> > http://narccap.ucar.edu/contrib/tools/util/  The "tas2temp" script
> > converts
> > degK to degC, and "pr2prec" converts precip from kg/m^2/s to mm/day.  The
> > commands to convert ps files from Pa to mbar would be entirely analogous.
> >
> > Relative humidity can be calculated from specific humidity, temperature,
> > and
> > pressure (variables huss, tas, and ps).  There's an NCL script
> > ("calc_humid.ncl", which also calculates dewpoint) in that
> > contrib/tools/ncl
> > directory on the website.
> >
> > I haven't had cause to calculate wet bulb temperatures yet, so I can't
> > offer
> > any tools to help with that yet, sorry.
> >
> > Cheers,
> >
> > --Seth
> >
> >
> > On Sun, 11 Mar 2012 11:19:00 -0600
> >  ping yang <pingyang.whu at gmail.com> wrote:
> > >Dear NARCCAP users,
> > >
> > >I need data for the following items with daily step and monthly step:
> > >
> > >•Precipitation –Units (mm)
> > >
> > >•Surface Air temperature –Units (°C)
> > >
> > >•Surface Air pressure –Units (mbars)
> > >
> > >•Humidity (relative )
> > >
> > >•Wet bulb temperature –Units (°C)
> > >
> > >•Cloud Cover
> > >
> > >I looked into the NARCCAP data tables, actually there are so much
> > >information that I am a little confusing,  e.g., I found the Max/Min
> > >Surface air temperature data in daily but the instantaneous surface
> > >air temperature data in 3 hours, and some data like Wet bulb
> > >temperature I don't know how it was classified or named in the NARCCAP
> > >dataset.  Is here someone has the same experiences who can give me
> > >some instructiona on how to get those data or some suggestion on how
> > >to process the available data?
> > >
> > >All the Best,
> > >
> > >Ping
> > >--
> > >Ping Yang, Ph.D.
> > >Postdoctoral Research Associate
> > >CUNY Environmental Crossroads Initiative
> > >_______________________________________________
> > >narccap-discuss mailing list
> > >narccap-discuss at mailman.ucar.edu
> > >http://mailman.ucar.edu/mailman/listinfo/narccap-discuss
> >
> > _______________________________________________
> > narccap-discuss mailing list
> > narccap-discuss at mailman.ucar.edu
> > http://mailman.ucar.edu/mailman/listinfo/narccap-discuss
> >
>
>
>
> --
> Ping Yang, Ph.D.
> CUNY Environmental Crossroads Initiative
> Marshak Science Building - Suite 925
> The City College of New York - CUNY
> 160 Convent Avenue, New York NY 10031
> Phone: 212-650-5769
> Fax: 212-650-7064
>  _______________________________________________
> narccap-discuss mailing list
> narccap-discuss at mailman.ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/narccap-discuss
>



-- 
PhD Candidate
Department of Civil & Environmental Eng.
University of Michigan
1351 Beal Avenue, 126 EWRE
Ann Arbor, MI 48109-2125
linglihe at umich.edu