Science Fiction or What


The smoky air from the Mendocino County wildfires 100 miles away, hovering above the bay area. CA

1pm


12p

11am - is it lightening up?

10:30am - Red mixed with gray clouds

10am: A distinct orange, tending to orange-red

9:30am: Yellow Orange Skies

7am - dark grey skies. light ash fall 
7am Sep 9, 2020

An Explanation

— is caused by smoke from the over 300,000-acre August Complex fires burning in Mendocino and neighboring counties.

The Bay Area is directly downwind from the fires and strong winds are pushing smoke about 5,000 feet up in the air through a process called “turbulent mixing.” Or, as NWS meteorologist Drew Peterson put it: “It’s kind of like if there’s a pile of dust, and someone took a leaf blower to it and flung it all up into the air.”

The sky is orange because longer wavelength light (reds and oranges) are able to push through smoke particulates, whereas shorter wavelengths (blues and purples) are filtered out. And it has gotten progressively darker since (the largely invisible) sunrise. According to the National Weather Service, as the winds weaken, gravity takes over as the primary vertical transport of the smoke. “Suspended smoke will descend closer to the surface and could lead to darker skies and worsening air quality today,” the agency posted on Twitter, adding, “This is beyond the scope of our models so we rely on your reports!”

Berkeleyans have been sharing dramatic photo on social media since they woke up — describing the view as a “nuclear winter” or  the “Twilight Zone.”

The good news — and boy do we need good news on an eerie day like today — is that the air quality is actually pretty good in Berkeley. According to the Bay Area Air Quality Management District monitor at the Aquatic Park, it was at the yellow, “moderate” level (79 MP2.5) by the 7 a.m. count.




 

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