Install a skylight that opens/removes
Windows are not made for use on roofs.
There are a variety of skylight assemblies on the market intended for installation in houses. Find one that pops or tilts up, and whose mechanism can be disassembled to remove the plexiglass panel.
You may have re-roof the building to make an effective join to the skylight. It's up to you, I don't know if you care how much a well house leaks.
Or, put a stovepipe there
with proper anti-rain baffles. I gather that an 8" stove pipe will suffice, or even 6" perhaps.
They make specific assemblies designed to pass through a roof.