[RegCNET] Re: ECHAM Runs

[moetasim]

I have few comments on this:

1)Its bit difficult to compare RegCM and PRECIS region by region becasue the 
color level do not match. It would have been much better, if Nazrul had 
taken care of color levels. Also, reanalysis driven output can not be 
compared with GCM drvien output when RCMs are different.

2) RegCM is overestimating precipitation this is one thing but the main bad 
thing is that this overestimation is of spotty nature. There is not any real 
pattern of overestimation at subregional scale. I consider these over 
estimation spots as a real problem in RegCM for South Asian simulations. 
This problem is not only due to convective parametrization. There is 
something wrong somewhere else (I can't guess) may be in large scale, may be 
in cloud physics, may be in ....which is creating these spots. 

3) PRECIS is giving ~zero precipitation in a narrow band near western-ghats 
and over Srilanka in Monsoon months. I think this zero precipitation band is 
wrong and can not be regarded as a good simulation. Overall, models do 
perform well sometime for a particular sub-region as PRECIS do for some 
parts of South Asia. Comparison between these two is very difficult again 
due to different sets of boundary conditions and mismatching color levels.
 
Anyway, remove this spotty precp and see RegCM doing better in South Asia. 
Jeremy : Did you ask them to try running RegCM without SUBEX? Do you think 
that overestimation is due to Emanuel? Emanuel would be best for this region 
if we could control over-estimation of precp both in summer n winter.

MOet

  

`On Tue, 4 Oct 2005 23:07:59 +0600, Dr. Md. Nazrul Islam wrote
> Hi Jeremy and Faisal,
> It seems that ECHAM result of RegCM is beeter than that we obtained 
> using Grell-AS/FC. For your kind information, PRECIS results are 
> included with Faisal's monthly and seasonal values. In my openion, 
> both model detected well the precipitation band (i) through Nepal 
> extended more NW and SE, and 
> (ii) Western Ghat of India. Some dissimilarities are (i) in and 
> around Shillong hill of India(where Cherapunji, the highest rainfall 
> recorded station existed) and (ii) over the Bay of Bengal.
> 
> I am looking for the ECHAM version of RegCM and analyzing detail for 
> longterm data, we may find better conclusion.
> 
> For your kind information, PRECIS can measure about 92% of surface 
> rain over Bangladesh.
> 
> Nazrul
> 
> Dr. Md. Nazrul Islam
> Associate Professor
> Department of Physics
> Bangladesh University of Engineering and Technology
> Dhaka-1000, Bangladesh
> 
> Phone: 880 2 966 5650 (PABX)
> FAX: 880 2 861 3026, 880 2 861 3046
> 
> ---------- Original Message -----------
> From: "S. Faisal Saeed" <faisal.saeed at gcisc.org.pk>
> To: "Pal Jeremy" <jpal at ictp.it>
> Cc: "jagadish karmacharya" <j_karmacharya at yahoo.com>, "archana 
> shrestha" <archanamet at yahoo.com>, "Dr. Md. Nazrul islam" 
> <mnislam at phy.buet.ac.bd>, "BI XUNQIANG" <bixq at ictp.it>, "Filippo 
> Giorgi" <giorgi at ictp.it>, <shahbazmehmood at gmail.com>, 
<madnanabid at gmail.com>
> Sent: Mon, 3 Oct 2005 11:54:36 +0500
> Subject: ECHAM Runs
> 
> > Hi Jeremy,
> > 
> > The results of ECHAM runs for 1981 are attached. It was a 2 year run
> > 1980-1981. Overall the monthly and seasonal patterns of Precip and 
> > Temp are good. In the months of Oct, Nov and Dec (post-monsoon) the 
> > precip is highly over-estimated by the model over northern Pakistan, 
> > these are quite dry months in Pak. The seasonal winter JFM 
> > precipitation with ECHAM over northern Pakistan is quite reasonable, 
> > the climatological value JFM of precip is 4 mm/day, while year to 
> > year values may go up to 6 mm/day at some stations, where as in the 
> > Model with ERA40 it is about 8-9 mm/day.
> > 
> > Best,
> > Faisal
> > __________________________________________________________________
> > SYED Faisal Saeed - Meteorologist
> > Global Change Impact Studies Centre
> > 1st Floor, Saudi - Pak Tower, Blue Area,
> > P.O.Box No 3022 , Islamabad, Pakistan.
> > Tel:      +92-51-9219785
> > Fax:     +92-51-9219787
> > e-mail:    faisal.saeed at gcisc.org.pk
> > __________________________________________________________________
> ------- End of Original Message -------