January 09, 2015

Stink Fog Returns and Hits New Victims

Stink fog has returned and expanded it range, driving trash-talking against Seattle, particularly by Panther's fans and Tacoma residents.   And new insights into the origin of the mysterious odors are now available.

As described in my previous blog and numerous media accounts, a noxious odor reminiscent of either a bathroom or pulp mill hit Seattle, Bainbridge Island, and parts of the Kitsap Peninsula on Wednesday morning.

The coverage of this unfortunate phenomenon has gone national including the NY Post and the Charlotte North Carolina NBC affiliate who suggested that BOTH our city and the Seahawk's game play stank.  They will regret saying that.

But this mysterious odoriferous phenomenon is back and has expanded its range.   Today, many residents of Bainbridge Island were greeted by the now familiar stench.  Biking home this evening  I was hit by it in north Seattle.  And most importantly, large number of Victoria residents were disturbed by the sulfurous smell, as did some residents of Lopez Island.

A major contributor to the regional smell problem has been very light winds and an extraordinarily strong and very low level inversion, which caps pollutants near the surface.  Here are plots of temperature with height in Seattle on Wednesday morning and this morning (Friday).  Very strong inversion and a very shallow layer of cold, polluted air near the surface.  Unusual persistence of an extraordinarily shallow air layer capped by an inversion.

There has been an animated debate of where the smell is coming from.  One idea was that the heavy rains resulted in soggy fields with decaying organic matter, leading to the smells.  But a careful examination of the location of the smell reports indicated few on the eastside (e.g,, Redmond, Duvall, etc.) where it should have been worst.  Cross that out.

Another idea was that low tide exposed smelly tide flats.  This is attractive, since many of the locations getting hit are in the vicinity of water.    However,  the tides have not been unusually low, nor has low tide extended over a particularly long period.  Perhaps a contributor, but it doesn't explain the extended length of the smell.

Another suggestion  was that we were smelling the effluent from the Tacoma or Port Townsend pulp mills.  Perhaps a contributor, but it unlikely that two point sources could have could have produced the smell over such an extended area.

Perhaps the most outrageous suggestion, made by a reporter from a Tacoma newspaper was that Big Bertha, the broken tunnel boring machine under Seattle, hit a huge pocket of decaying matter, and that the smell ascended from the chamber being drilled to replace the broken sections of Bertha.  This Tacoma reporter noted that the access hole to Bertha looks like a giant toilet (see image, it does).

My conclusion, and one supported by my friends at the Puget Sound Clean Air Agency, is that there is no one cause.  The very strong inversion, shallow cold air layer, and weak winds were ideal for maintaining pollutants near the ground.  There are many sources of bathroom and and sulfurous smells that all contribute:  gases released from drains and waste pipes, exposed tide flats, rotting garbage (and Seattle's new composting law ensures there is plenty of that), industrial waste and pulp mills, and many more.    I often get major smell from the nearby Mathews Beach sewer pump station and it spread over thousands of feet.   Reports and my experience suggests the smell is intermittent and localized, suggesting local sources.

In some ways, the low inversion was like an odor microscope, making apparent smells that normally are diffused deep in the atmosphere.

Panther fans can tease us about the smells, but tomorrow a weak front will clean the air, the inversion will lift, and Seahawks will rise ascendant.


  1. Victoria and Lopez may have it along with Seattle, but it hasn't made it out onto the Olympic Penninsula, even as far eastward as Sequim. And we've been in the fog for days.

    Which I suppose could support the idea that its just an accumulation from many sources. There isn't much population or smelly industry out here if you discount Port Townsend.

    And Port Townsend's stink generally stays in the Puget Sound area thanks to prevailing westerlies and to a lesser degree terrain.

    John Marshall

  2. Could it be that the heavy rains we had about 1 1/2 weeks ago caused sewer overflow into the storm drains? We have not had a decent rain since, so if there is fetid water in the storm drains, it might just be sitting there and festering. With the inversion in place and light winds, the noxious aromas remain in place for all to smell.

  3. Professor Mass, you were the very first professor I had in college. I took Atmospheric Sciences 101 at the U, and you walked into the lecture hall, every bit the Professor stereotype I had in my head--wearing a tweed blazer, scarf, and with a wild head of hair. You were one of my favorite professors. I love your blog. Thank you for the constant flow of educational, informational blog posts speckled with humor.

  4. I live just to the north of Sequim and it has stunk all day Saturday. The worst we've ever experienced it. No wind at all.

  5. I wonder how strongly the stink is a function of altitude. Michael DeMarco had it bad just north of Sequim (which would also put him close to sea level) while we live just south of Sequim at a thousand feet altitude.

    Perhaps that confirms that it's an unusually shallow inversion, concentrating the odor in the bottom few hundred feet.

    Here's hoping for some wind and mixing.

  6. Thanks for the report - this story inspired me to draw this foggy sketch

  7. I don't know if this morning's fog was stinky, but it looked really cool over the Kitsap Peninsula from the Seattle side! I took this pic at 8am today:

  8. That smell? It's us. Our cars, our poop, our garbage, our emissions of all kinds - trapped very near the ground so that we have to deal with most of our own stench in a more direct way than we're used to. Thanks for the lesson, atmosphere. Solar power, electricity, recycling, and less consumption all look (and smell) a lot better now.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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