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Steve Hostetler
US Geological Survey
Department of Geosciences
Room 104 Wilikinson Hall
Oregon State University
Corvallis, OR 97331-5560
tel 541 737-8928 fax 541 737-1200

Hi Mike,
When the lake is turned off, the lake surface is treated as inland water 
body(patch) in the land surface scheme(BATS). In which case, the fluxes 
over the water patch may be different from the rest of the land cells. 
But, when you use the 1D lake, you introduce the vertical flux transport 
within the water column(full depth) and to the atmosphere which mayl 
signficantly change the atmospheric response; depending on the size and 
depth of the lake.


The reference below may be useful.  They used one of the original 
versions of RegCM. The lake model has not changed so much,  I think. You 
could also check Hostetler et al., 1993 (check details in the ref. below).

*
*Gary T. Bates, Steven W. Hostetler, and Filippo Giorgi, 1995: Two-Year 
Simulation of the Great Lakes Region with a Coupled Modeling System. 
Monthly Weather Review:123, 1505 1522
 Richard


Michael Notaro wrote:

  

Thanks, Richard!  You have been quite helpful.  I will look at those  
papers.

I want to clarify one thing.
When the lake is "turned off" then, does that mean the the lake does  
not exist
and it is treated as land (bare soil, forest?)?  So, if I run with  
and without the lake model,
the difference is the effect of the existence of those lakes on the  
atmosphere?  I was interested
in investigating how the lakes affect the local climate.

How is lake ice treated?  Unfortunately, the papers on Africa won't  
address that since
they are for a warm climate.

Does anyone know of papers using RegCM3 and the lake model for the  
Great Lakes?

Thanks, Mike



On Jun 28, 2007, at 8:33 AM, Richard Anyah wrote:

    

Hi Mike,

The following publications may be relevant, though they use lake  
model from variants of the RegCM family for Lake Victroia in  
equatorial eastern Africa.




      

I have some general questions about the lake model in RegCM3.
In particular, relating to the Great Lakes.

Could someone email me the references to some papers that use the
lake model with regcm3?  I would like to see previous applications

        

1.  Song, Y., F.H.M. Semazzi and L. Xie, 2002: Development of a  
coupled regional climate simulation model for the Lake Victoria  
Basin. In /The East African Great Lakes,Limnology,Paleolimnology  and 
Biodiversity/, Odada E and Olago G(eds). Gordon and Breach:  
Armsterdam: 141-154

2.  Song, Y., F.H.M. Semazzi and L. Xie, and L.J. Ogallo, 2004: A  
coupled regional climate model for Lake Victoria basin of East  
Africa. /Int. J. Climatol/. *24*, 57-75


3.   Anyah, R.O., and F. H. M. Semazzi, 2004: Simulation of the  
response of Lake Victoria basin climate to lake surface  
temperatures./Theor. Appl. Climatol/,* 79, *55-69


4.   Anyah, R.O., F.H.M. Semazzi and Lian Xie, 2006: Simulated  
physical mechanisms associated with multi-scale climate variability  
over Lake Victoria Basin in East Africa, Monthly Weather Review:  
134,3588-3609

      

What dynamics does the lake model simulate?  Lake ice fluctuations?
Changes in lake level?

        

       You may have to compute changes in E, P and horizonatal  
mosture convergence to infer lake level fluctuations.
      Also the 1D lake use simplified vertical exhange of moisture  
and heat between the lake and the atmosphere.(See refs. 1, 2 and 4  
above)

      

If the lake model is turned off, does the model assume  
climatological  lake
temperatures or is the lake replaced by land?

        

As far as I know  when the lake is tuurned off, the "lake" surface  
temperature uses the  surface temperature, unless you physically  
prescribe 'climatological' temperature over the lake surface



Hope the information may be helpful.

Richard

-- 
------------------------------------------------
Richard Anyah
Research Associate
Center for Environmental Prediction
Department of Environmental Sciences
Rutgers University
14 College Farm RD
New Brunswick, NJ 08901-8551
Phone: (732) 932 9735
Fax:     (732) 932 8644
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