Hi @chenhui.jin I was talking to @alanah.chapman yesterday at the roundtable. Alanah is going to try to run rAM3 at very high latitudes for some sea ice / aerosol studies.
We were discussing the same issues you are raising, and we discovered this old thread on the hive.
I would reach out to @ZhangchengPei to ask about using the other orography datasets that have coverage over Antarctica.
I don’t believe anyone has yet run rAM3 using those other datasets. But there is definite interest in doing so.