Is this Under-Extrusion?

[gsug]

I'm Printing with Matter Hackers Pro Series PLA on a Pro2 with Slice engineering's copperhead upgrade kit.

I know my bed is level and it looks as though some sections are very close to a good z-offset and others look off. The prints are completing and for this application top layer finish isn't a priority so I don't mind. But I know this will become a problem when I need to print something with a clean looking top or bottom face. Pictures attached are from the top and bottom of a recently completed print, do I have some under-extrusion occurring? Should I be adjusting the flowrate percentage in the filament settings tab? Any and all help is appreciated!