[RegCNET] underestimated diurnal temperature range montly means?

[XUNQIANG BI]

Hi, Matteo:

I guess that the way of your calculation might not be correct.

Which way you used ?

If you like, you can try my postproc (DAY_SRF.f under
RegCM/Commons/DAY_MONTH),

Suppose you output SRF fields every 3 hour. then in SRF.yyyymmddhh
file, you have 8 time slices in one day. The right way to calculate
TAMAX is find the maximum among the 8 time slices firstly, then
do the average of those maximun to get the monthly mean.

You should do for TAMIN in a similar way. Then calculate the
TGMAX - TGMIN. I am sure you should get the magnitude greater than 1K.

Best regards,
Xunqiang Bi


On Mon, 2 Jul 2007, Matteo Zampieri wrote:

> Hi All,
>
> I'm using RegCM over Europe, I'm doing an hindcast for year 1994
> using a similar configuration of the Practice Run but with a wider
> area and using ERA40 as boundary conditions (domain.param is attached)
>
> I think that the model diurnal temporal range, computed as TAMAX-TAMIN
> from the SFR file after montly means are computed, is underestimated.
>
> I'm attaching two plots showing the mean diurnal temporal range for
> january and august. In January, in Central Europe, it is only 1 K
>
> Maybe a possible reason could be that tamax and tamin are computed from
> the 4-hourly model output but I don't think it is enough to explain
> this behaviour
>
> thank you very much to anyone can help me!
>
> bests,
> Matteo
>
> ---------------------------------------------
> Matteo Zampieri
> ISAC-CNR
> Strada Prov. Lecce-Monteroni km 1.2
> 73100 LECCE (IT)
> email: M.Zampieri at isac.cnr.it - @lmd.ens.fr
> Tel: +39 0832 29 7105 - Fax: +39 0832 29 7547
> ---------------------------------------------

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   Dr. Xunqiang Bi         email:bixq at ictp.it
   Earth System Physics 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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