[RegCNET] tmax and tmin
Wm. J. Gutowski
gutowski at iastate.edu
Wed Nov 16 13:35:10 CET 2005
Tomas:
Do you know how well stations around the
world adhere to the WMO reset time? (BTW - what
is their recommendation?)
Bill
At 11:19 AM +0100 05.11.16, Tomá” Halenka wrote:
>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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>> RegCNET at lists.ictp.it
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>>
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>~ Dr. Xunqiang Bi email:bixq at ictp.it ~
>~ Physics of Weather and Climate Group ~
>~ The Abdus Salam ICTP ~
>~ Strada Costiera, 11 ~
>~ P.O. BOX 586, 34100 Trieste, ITALY ~
>~ Tel: +39-040-2240302 Fax: +39-040-2240449 ~
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--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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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