Extracting SST information in a ROMS model result

[lcbernardo]

Dear ROMS users,

I'm not sure if this is a simple question with an obvious answer. Lately I've become a bit confused regarding the vertical sigma layer configuration in ROMS, especially since I've been outputting the z_rho variable in my runs. When plotting temperature using the depth information from this variable, the temperature at the shallowest layer is not really at the surface, and may even be at 5 meters or deeper depending on the bathymetry. Now, in case I would like to compare the model results with say satellite derived SST or surface drifter data, what would be the recommended approach? Is there a variable that contains the temperatures exactly at the water surface which I'm not noticing? Or is interpolation/extrapolation to shallower depths using a user-defined z-level coordinate system (which I imagine will produce a lot of NaNs) also possible?

Thanks,
Lawrence