[NARCCAP-discuss] Great Lakes’ temperatures and ice fraction

[Seth McGinnis]

Hi Biljana,

There is a description of the RCM3-GFDL treatment of the Great Lakes on the
caveats page; it's just before section about the RCM3-CGCM3 runs.

For the WRFG-CGCM3 and HRM3-HadCM3 runs, there was nothing exceptional
about the treatment of the Great Lakes; they were handled in the standard way
for those models:

In the WRFG-CGCM3 runs, lake temperatures were assigned by spatially
interpolating the sea surface temperatures from the GCM from coast to coast to
the locations of the lakes.  Lake ice forms when the assigned lake temperature
is below 271.4K or when sea ice is identified by the sea ice mask from the GCM.
 
(This comes from the description of how they were handled in the WRFG-CCSM
current run.)

In the HRM3-HadCM3 runs, the lake temperatures come directly from the driving
GCM. When a lake is resolved in the RCM but unresolved in the GCM, the
temperature of the lake is assigned the temperature of the nearest GCM sea
point.

For more detailed information on the handling of the lakes, you will need to
contact the respective modeling groups.  The members of the groups and links 
to contact info for them in the NARCCAP participants directory can be found on 
the Participants page on the website: 
http://www.narccap.ucar.edu/about/participants.html

Finally, the land-sea mask has been provided for the RegCM3 runs; it's in the
Table 4 directory with the other sftlf files: 
http://www.narccap.ucar.edu/data/table4/

Cheers,

--Seth

On Mon, 6 May 2013 08:38:42 -0400
 Biljana Music <music.biljana at ouranos.ca> wrote:
>Hi,
>
>I analyzed six pairs of present/future RCM climate runs performed for the
>NARCCAP project (CRCM-CGCM3; CRCM-CCSM; HRM3-GFDL; HRM3-HadCM3;
>WRFG-CGCM3;WRFG-CCSM) to assess the projected changes in the Great Lakes' Net
>Basin Supply (precipitation over lake plus runoff to the lakes minus
>evaporation from the lake surface). I would like to have more information
>regarding the Great Lakes’ temperatures and ice fraction calculation for both
>current and future climate runs. I found some information
>(http://www.narccap.ucar.edu/about/caveats.html) for the following runs:
>HRM3-CCSM, WRFG-CCSM and RegCM3-CGCM3. However, there is no description of the
>Great Lakes’ treatment in the HRM3-HADCM3, WRFG-CGCM3 and RegCM3-GFDL runs.
>Also, I would like to know why the land-sea mask is not provided for the
>RegCM3 runs.
>
>I would be very grateful to anyone able to answer those requests. 
>
>Dr. Biljana Music
>Research Scientist
>Ouranos - Consortium on Regional Climatology and Adaptation to Climate Change
>550 Sherbrooke West, West Tower, 19th floor
>Montreal, QC, H3A 1B9, Canada
>music.biljana at ouranos.ca
>http://www.ouranos.ca
>
>
>
>
>
>
>
>
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