[stephengillie]

Why does the Grand Canyon have such a huge pocket of CO? It's over 1200ppbv. Is there currently a forest fire there? The air quality there looks as bad as over Staten Island or some Chinese cities.

[keithlfrost]

That pocket looks rather like an anomaly in the data. There is a very large coal-fired power plant (Navajo Generating Station) near Page, Arizona, though.

[jccooper]

There's a major fire south of that, in the middle of the state. But not right there, so far as I know.