Hi Judy,Indeed it should be possible to study the effect of GrIS topography on the atmosphere using CESM.If the interest is just in seeing how prescribed topography changes affect, e.g, atmospheric circulation, I suspect a straight F compset (active land, active atmosphere) may work OK. Basically, if you're prescribing your own topography datasets, you don't need an active ice sheet (which the 'G' stands for). In that case, you could use routines which:1) update the Greenland topography within the global topography dataset2) update the smoothed atmospheric topography and surface roughness fields the atmosphere seesThese routines can work in a 'time-evolving' sense, though it would be very computationally expensive to run a realistically-evolving GrIS deglaciation over thousands of years. I have run an extreme 100-year transient deglaciation, but only for testing purposes. Alternatively, it would be easier to simply do snapshot simulations for various geometries.Attached is a poster from a few years ago describing basic testing of the transient topography updating scheme.One comment: we are having our annual Land Ice Working Group meeting Feb 9/10 in Boulder, CO. You'd be welcome to come if you can (likely no travel support available at this time, $50 registration fee, see website at https://www2.cesm.ucar.edu/events/meetings/20160208). It could be a great way to discuss your ideas in person with myself and other relevant LIWG people.If you want to continue following up with this idea, let's take this conversation to email: I am at fyke@lanl.govcheers, Jeremy Fyke (Los Alamos National Laboratory)
