I get annoyed when commenters make back and forth claims without ever providing any citations so I did a Google and found myself on a NASA page. According to that page it's ~1360 W/m^2 at the top of the atmosphere, but by the time it gets to the surface it seems to average out to only about 340 W/m^2[1].

[1] https://earthobservatory.nasa.gov/features/EnergyBalance/pag...

You misread the source. The average is for the entire planet, parts of which are covered by clouds, and half of which is at night. 1 kW/m^2 is a typical value for peak insolations outside extreme latitudes. If the atmosphere absorbed significantly more than that, you could not see very far.

Your right - I said average but didn't go into specifics and so my message was unclear. But it's helpful to have a source to discuss, isn't it?

Thank you, you're right, but I can't update my post now. Argh. I shouldn't have added "ignoring ..."