That was an awful sky for Arizona yesterday. Thank heavens those kinds of days are rare here. Here are a few more shots of that rare smoky layer day yesterday, including one at sunset where you can see some undulations in the layer. You may have noticed that as the day wore on, the smoke appeared to be getting lower, and starting to reduce the visibility toward our mountains. At the beginning of the day, the layer was well above any mountains around here; there was no apparent haze whatever below that layer. There is a tendency for layers of smoke to lower with time, much as middle and high clouds do before storms, and that was part of it, as well as a tendency to mix downward as the day warms up.
Of course, if you’re from back East or from southern California, you’re wondering, “What’s the problem?” You see much more haze and smoke (smog) than this all the time. Heck, back East in the summertime, its so blasted hazy in the humid air before a cold front cleans it out, that you can barely detect that the sky is blue!
Here are examples of what smog looks like, first, over Virginia from on top (yuk), and second, on the ground at Chincoteague Island (also, yuk).
So what’s the problem?
We don’t like you’re kind of sky here in Arizona, even when its not that bad.
But heavy aerosol concentrations indicated in these last two photos help cool the earth off. Here is more from NASA’s Earth Lab about that if you’re interested. Would you like a cooler earth in which you can’t see the sky and mountains, or a warmer one with a blue sky? Well, a warmer one with blue skies is why I moved to Arizona!
Again, back trajectories for air arriving at 4 km and 6 km above ground level over Tucson (about 13,000 and 20,000 feet above us) suggest that the smoke is coming across the Pacific from Asia. Here is another plot ending at 5 PM AST when the local photos were taken.
We can hope it will be gone today as the trajectories of the air coming over us begin to change.