Profound Impacts of Fireworks on Visibility and Air Quality

The visibility this morning was greatly reduced compared to yesterday and fireworks smoke played a major role.

Here is view from the Seattle PanoCan looking towards the Cascades at 9:30 AM this morning (Thursday, July 5).  Very hazy with the foothills barely visible.  The haze is from fireworks.

The day before at the same time (July 4th, of course).  Some clouds aloft, but MUCH better visibility.  You can even see Mt. Rainier.

Now you don't have to take my word for the existence of plumes of smoke from fireworks.... lets take a look at the observations taken by the Puget Sound Clean Air Agency.  Here is the amount of small particles in the air (PM2.5) on Seattle's Beacon Hill.  Huge and sharp increase of particles during the evening of July 4th, to values over 100 (micrograms per cubic meter).  This is in the unhealthy level.

But why was in hazy this morning looking east?  To figure this out, let's examine the particles levels at Bellevue (brown line) and North Bend, near the Cascade foothills (green line).   Big increase during the evening of the fourth, but the levels stayed relatively high!

I suspect a lot of the smoke over the populated area near Puget Sound got pushed towards the east this morning.  In fact, the time-height cross section of wind and temperature at Seattle Sand Point provided by Puget Sound Clean Air Agency (see below) does suggest this (below).  The winds were easterly during the afternoon  but switched to westerly at low levels for several hours overnight  (heights are in meters ASL, time in UTC increases to the left)

And don't think Seattle was the only place with smoke.  It was worse in Tacoma and Marysville, home of Boom City, had a problem as well (see below).

Last time I was watching the Lake Union fireworks display with students, staff, and faculty on the top of my building, and the smoke became increasingly extensive during the short show. 

By 11 PM, the smoky scene was beginning to look apocalyptic.

Several people told me they felt cold-like symptoms this morning from the left-over smoke.  In any case, air quality will improve rapidly now as a Pacific front moves through bringing an influx of clean, marine air.   

Finally, there may be a superior replacement for the smokey fireworks---performances of hundreds of drones with LED lights.    Check out this video to see what I mean.

from Cliff Mass Weather and Climate Blog https://ift.tt/2KATb8m