[RegCNET] Ozone tracer in RegCM3???

[bixq]

Hi, Maurice:

Fabien could answer your questions better.

On Wed, 19 Jan 2011, Maurice.McHugh at noaa.gov wrote:

>
> We are interested in using RegCM to perform transport modeling of ozone.
> However, we are unaware of RegCM’s exact chemical species transport 
> modeling capabilities.  We would prefer to not use chemistry schemes and 
> have ozone treated as an unreactive gas, however we can use chemistry 
> schemes if that’s the only option we have.
>
> There are two major areas we are concerned about:
> feeding our own 3D ozone concentration data and attaching a tracer.
> Is there a way to feed our own ozone concentration fields into RegCM?

Yes. In init.F90, if you search chia and chib, you can add some lines
like,
       do k=1,kz
       do j=1,jendx
         do i=1,iym1
           chia(i,k,j,1) = psa(i,j)* ozone(i,k,j)
           chib(i,k,j,1) = psa(i,j)* ozone(i,k,j)
         enddo
       enddo
       enddo

here, ozone fields you prepared has to be readed (and scattered 
for parallel code) previous, and in the units (kg/kg). Here itr=1
means that you'll just use SO2 for O3 to save your work.
> 
> If so, can the data be fed with the rest of the input fields or does it 
> need to be fed within the model itself?

It depends on which frequency ozone data you have, if you have monthly or
high frequency (weekly or daily), then you could also prepare the tendency
of ozone fields and use the leteral scheme (iboudy = 5), then bdyval.F90
also need to be edited.

> Once we have ozone in the model, how can we trace ozone transport?

If you just use idirect=1, ntr=1, nbin=4, and inpchtrname='SO2'.
Then you can get the ozone transport (idirect=1 means no radiation 
effects)

>Is it possible to add another tracer?  Or could we use one of the 
existing tracers (SOx, BC, dust, etc.) without disrupting model radiation calculations?

You see, I meantioned the 2nd way you proposed. I think this is easier.

You know, the above sentences are just a rough suggestions, some extra
arrays have to be added in module mod_chem.

F. Meleux (work with Filippo and Fabien) have done the similar work, see:

Meleux, F., F. Solmon and F. Giorgi, 2007: Increase in summer European 
ozone amounts due to climate change. Atmospheric Environment, 41, 
7577-7587. 
Giorgi, F., and F. Meleux, 2007: Modeling the regional effects of climate 
change on air quality. Comptes Rendus - Geoscience, 339, 721-733.

And Fibien knows the work in details.

Regards,
Xunqiang

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   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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