[RegCNET] tmax and tmin

[Tomáš Halenka]

Dear All,

Not bad hearing Tmax and Tmin will be included properly in new edition
of RegCM. But I would recommend to use WMO definition and reset time,
moreover, keep in mind it has to be done in local time as my opinion.

Best regards,

Tomas

*************************************************
RNDr. Tomas Halenka, CSc.
Charles University in Prague,
Faculty of Mathematics and Physics,
Department of Meteorology and Environment Protection,
V Holesovickach 2, 180 00  Prague 8,
Prague, Czech Republic,
Phone: +420 2 21912514
Fax:     +420 2 21912533
E-mail: tomas.halenka at mff.cuni.cz
*************************************************

-----Original Message-----
From: regcnet-bounces at lists.ictp.it
[mailto:regcnet-bounces at lists.ictp.it] On Behalf Of BI XUNQIANG
Sent: Wednesday, November 16, 2005 9:48 AM
To: Wm. J. Gutowski
Cc: Gao Xuejie; regcnet at lists.ictp.it
Subject: Re: [RegCNET] tmax and tmin


Dear Bill, Lara, and Gao:

In the next public released RegCM3 version, we will add Tmax, Tmin
and vertital velocity (for pressure level) as the standard output.

We will calculated Tmax and Tmin as the way Bill suggested (for
every land surface step, and reset at 00 UTC).

Any other fields are also necessary to be included ?

Thanks and best regards,

On Tue, 15 Nov 2005, Wm. J. Gutowski wrote:

> Dear Lara:
> 	I am not the expert on this, but I am pretty sure that observed
Tmin 
> and Tmax are obtained primarily from min/max thermometers, which
record the 
> highest and lowest temperature attained since the last time they were
reset. 
> They are almost always reset every 24 hours, though they don't all get
reset 
> at the same time.  That is, different stations, even in the same
country (or 
> in the US, the same state) may reset their thermometers at different
times of 
> the day.  This can induce a small bias in one station's climatological

> averages compared to what it would get if it reset at another time.
This is 
> documented in the literature somewhere, though I don't have the
reference 
> myself.
> 	Using the 3-hourly output will tend to reduce the diurnal
temperature 
> range you get because that is probably not sampling the extremes of
the day, 
> though I have not seen this reduction tabulated by anyone, and it
probably 
> depends on location and season.  Including a computation of the true
daily 
> min/max temperature would be just a few lines of code, and some of us 
> RegCNETers have undoubtedly done it for their version of the code - we
really 
> should have it as part of the standard model, I think.  There would
still be 
> the question of what time of day to "reset the thermometer", but in
model 
> intercomparisons I've been part of, we typically agree to go from 00
UTC - 00 
> UTC.
>
> Bill
>
> At 11:32 AM -0800 05.11.14, Lara Kueppers wrote:
>> Hi-
>> Awhile back I asked how Tmin and Tmax in the SRF output file were 
>> calculated. Here is Nellie's recent reply, in case anyone else is 
>> interested.:
>> 
>> "Hi Lara,
>> 
>> I just verified this with Bi...Tmin and Tmax are calculated from the
BATS 
>> output, so if you have the model output to the SRF file every 3
hours, then 
>> that is what the min and max are calculated from.  Bi thinks this is
a 
>> better way to do it since min and max temp observations are generally
taken 
>> from 3 or 6 hourly obs.  You can increase the frequency of the srf
output 
>> variables (in the regcm.in file) to see how much of difference it
would 
>> make in the diurnal temp range. "
>> 
>> --
>> ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
>> Lara M. Kueppers, PhD
>> Postgraduate Researcher
>> Department of Earth Sciences
>> University of California, Santa Cruz
>> 1156 High Street
>> Santa Cruz, CA  95064
>> USA
>> 
>> 831.459.3504 ph
>> 831.459.3074 fax
>> kueppers at pmc.ucsc.edu
>> 
>> _______________________________________________
>> RegCNET mailing list
>> RegCNET at lists.ictp.it
>> https://lists.ictp.it/mailman/listinfo/regcnet
>
>
> -- 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> William J. Gutowski, Jr.
> 3021 Agronomy Hall
> Dept. of Geological and
>     Atmospheric Sciences
> Iowa State University
> Dept. of Agronomy
> Ames, Iowa  50011-1010
>
> gutowski at iastate.edu
> Tel:1-515-294-5632
> Fax:1-515-294-2619
> http://www.ge-at.iastate.edu/
> http://rcmlab.agron.iastate.edu/
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
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>

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~  Dr. Xunqiang Bi         email:bixq at ictp.it  ~ 
~  Physics of Weather and Climate Group        ~
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