Hi, I downloaded surface data at /glade/p/cesm/cseg/inputdata/lnd/clm2/surfdata_map/surfdata_0.9x1.25_16pfts_simyr2000_c170428.nc and plot contour maps of tree fraction. Oddly, there are some grids with trees in the ocean (see the left figure).
Later I found that those grids in the ocean are actually not used (or not output) in my simulation. Say if I run an I2000 simulation with this surface data, the output at tree PFTs actually does not include those weird grids over the ocean (see the right figure). But the surface data do indicate that there are trees in those grids...
I wonder if there is any reason for this? My guess is that the output from CLM automatically masks out some grids beyond the major continents? I also notice this phenomenon for the lake land units. i.e. some grids in the surface data with positive lake fractions cannot be found in the lake output.
Any help is appreciated. Thank you!

Later I found that those grids in the ocean are actually not used (or not output) in my simulation. Say if I run an I2000 simulation with this surface data, the output at tree PFTs actually does not include those weird grids over the ocean (see the right figure). But the surface data do indicate that there are trees in those grids...
I wonder if there is any reason for this? My guess is that the output from CLM automatically masks out some grids beyond the major continents? I also notice this phenomenon for the lake land units. i.e. some grids in the surface data with positive lake fractions cannot be found in the lake output.
Any help is appreciated. Thank you!
