Tuesday, August 26, 2014

The Hazy Pacific Northwest

More than one person has commented to me about about how hazy the skies have been lately.  In contrast, early in the summer, the skies were often starkly blue with the mountains sharply silhouetted on the horizon.

Want to see the difference between early July and now?  Look at these samples from the Puget Sound Clean Air Agency visibility cameras, one from July 7th and the other from yesterday morning:


The reason for the loss of visibility?

Smoke from wildfires all around us.  There are many fires in British Columbia to our north (see map)

And lots of fires over Washington, Oregon,  Idaho, and California (see image)

So if the winds are from North to East to South, smoky air is moving over us.  During the past few days we have gotten smoke from British Columbia fires, smoke that first moved west and then south.   Here is the MODIS satellite imagine on Monday...can you see the smoke over the interior of BC that is moving towards the coast?


We can run a trajectory calculation (Hysplit) to see where the air over us Monday night came from (see graphic)...yep...from coastal British Columbia.

The wildfire smoke has caused the air quality in a number of Northwest locations to decline to moderate.  Here is an example from Seattle...Queen Anne Hill.


This is not the only summer we have experienced worsening visibility from regional wildfires and won't be the last.

4 comments:

I.F. said...

And at other times, isn't moisture the issue? Once the fire season ends with some rain this fall, isn't the clearest view looking west at the Olympics on those cooler days when the there is high pressure and a north breeze?

SchmittMath said...

I am surprised the air quality is moderate, seems very bad in the Port Angeles and Sequim areas. I drive into Sequim and wonder where the fire is, you can barely see the mountains!

Lori said...

We installed solar panels on our roof earlier this summer and the output is down 25% since mid July. We were just wondering how much is due to haze- it looks like a lot!

Ansel said...

I saw a lot of smoke much of the way up to Desolation Sound, up the Sunshine Coast, on the cruise from which I have just returned. It really is too bad, gives the sun a reddish Los Angeles look. Somehow, it does seem that such fires are becoming more common...

It is rarely pointed out (so I will do so) that the East Coast humidity (where I originated) has a good side: Forest fires are uncommon in most of New England.