Branch run with different land-sea mask

[flocolleoni@gmail_com]

Hi all, I have a specific question regarding branch run and the use of different land sea masks. I am running a glaciationwhich uses ICE5G Laurentide ice sheet at 21 kyrs BP and the Eurasian ice sheet at 140 kyrs BP. Basically what I would like to do is:1- a first run spun-up to this glacial configuration2- then branch from this run a new simulation with a smaller Laurentide than in the first run, which implies a land sea mask more or less similarto present-day over North America My question is: is it possible to do that?I know that you performed a transient simulation of the last deglaciation. how did you do that? did you modifythe land sea mask as well to prescribe different ice sheets configuration from ICE-5G? Cheers Florence

 

[nanr]

Hi Flo -When we ran the TraCE (CCSM3 T31) transient simulation of the last deglaciation we periodically changed the land mask to simulate changing sea level (http://www.cgd.ucar.edu/ccr/TraCE/).  Each time we changed the land/sea mask, we also created new coupler mapping files and a new surface dataset to match.  In general, rising sea level is more difficult to accommodate since you need to extrapolate temp and salinity into the new ocean cells.  Your experiment is definitely possible, but will require a lot of work to create the initial conditions that you want.Nan