Wednesday, January 7, 2015

Stink Fog Hits Seattle

The messages starting flooding in just after midnight last night.   Fog had moved into the region accompanied by pungent odors reminiscent of manure and pulp mills.

A number of local media outlets produced stories about this unfortunate fragrance, such as the Weekly and the Stranger.



Twitter was full of complaints, some perhaps not suitable for a younger audience.

The smell was not limited to Seattle but was also noted on Bainbridge Island and north/south of the city.

My curiosity aroused, I starting looking into this relatively unusual situation.

The meteorology was favorable in many ways.   With high pressure building over the region, a very strong low-level inversion (temperature warming with height) developed over Puget Sound.  Here is the plot at Seattle for a few hours last night.  There was a shallow cool layer 100-200 meters thick which contained the fog and strong warming (the inversion above)
Inversions are very stable layers that act as lids--keeps pollutants and smells concentrated at low levels.

And then there were the winds...they were very weak (as shown by this plot around Seattle around 4 AM, the circles with dots in the middle indicate calm winds).   Weak winds produce little turbulence and vertical mixing.  That helps keep smells in.
So the meteorology was favorable to keep odors near the surface, but what were their origin?  We get this kind of weather configuration all the time with no major smell issues.  What was different this time?

I checked with Seattle Public Utilities... there was no sewer outflows/spills and they said that was true for King County.   The winds were weak, so there was no reason to expect strong air flows from regional pulp mills.

But there was something different this time....we just had major flooding...not in Seattle, but in communities to our east.   Flooding followed by relatively warm temperatures.  

It seems logical.  Large areas were covered with water and during the last day the water had receded.  Some of it farm land.  Manure and some sewage got spread over it.   Might the there have been the release of SO2 (sulfur dioxide) as the moist land stewed a bit in the warm temperatures yesterday?

Smell generation area?

As a check, I looked at the air trajectories (3D air paths) in the UW high resolution model; specifically 24h trajectories ending 10 PM yesterday.  The air came from the east side!


I talked to James Rufo Hill of Seattle Public Utilities and he thought the flooded ground idea was a reasonable hypothesis.  However, such smell scenarios are bit out of my area of expertise (thank god!), so I will leave this to my readers to push this further.

And keep in mind it could have been worse.  In fact, there is a movie (The Fog) about an unusual fog in Oregon that brought not only unpleasant odors, but zombies as well.   I will be content with the smell.





29 comments:

Unknown said...

Dr. Mass,

There was also a good and long low tide last night (-1.0 ft MLLW), exposing our tidal flats for most of the night. The natural anaerobic bacterial communities in our mudflats breath sulfates and respire sulfides, (that "rotten egg" smell that many were noting). I could imagine that with an inversion and no wind, that the smell would be quite noticeable.

Brad Ginn said...

I've had 4 different people comment to me since yesterday about the aroma in Poulsbo. Three said it smelled like a pulp mill, one said it was cow manure.

John W said...

I like the tidal flats idea as well. I spent a lot of time near tidal flats in south Jersey and the smell was very similar. We don't normally get the odor hete because the tidal flats are only exposed when the tides are more extreme.

Unknown said...

I didn't notice it in Bellevue, but a friend from Seattle did. Hey, another topic, are we now duplicating last winter--Midwest polar vortex, wet NW and more California drought?

BillC said...

Could be Port Townsend Paper Mill. Winds have been directly out of the NW last couple of days headed right towards Seattle...

AndrewM said...

I noticed it strongly in Poulsbo and it smelled very much like the Port Townsend paper mill, not tide flats. I think there was a very weak north wind as well.

Metro Market Catering said...

I agree with those that think that the culprit is the pulp mill. We were in Pt. Townsend recently and the orders match. The smell was very noticeable on Bainbridge.

Cliff Mass said...

Regarding the Port Townsend pulp mill, the air trajectories and wind directions did not seem right to bring that stuff over us..but I can't be sure about it....cliff

Beth said...

I noticed it on Bainbridge. I actually have noticed it a couple of times in the last couple months and thought itwas unusual. We live a 3/4 of a mile from the head of eagle harbor. Tidal flats seem a reasonable idea.

Loco Geologo said...

I suspect the odors were volatile chemicals (gases) that usually dissipate into the atmosphere, but as Cliff clearly showed were trapped creating the stink fog. Outside of the pulp mill areas I'm assuming the smells were from methane, hydrogen sulfide, and other sewage degradation daughter products. In the rural areas most residences are on septic which produce theses gases across the leach field (generally they dispitate before they can reach high enough concentrations to smell). For the urban areas it's generally assumed that 10% of raw sewage leaks from the sewer lines (that's why the water lines are above the sewer line); as such the sewage lines can thought of as big leach lines. Don't worry the bacteria break most of it down to nitrate and resistant pharmaceuticals within a short distance of the line. The sweet sewage smell on Bainbridge smelled like a freshly opened leach field. However, an argument against this source would be the high pressure causing the fog would have also pushed the soil-gas down inhibiting "off-gassing".

Gpacharlie said...

Breweries?

Bob Hall said...

I'm still convinced it was the PT pulp mill. Winds were light, but they were Northerly -- go look at the ferry data. 5 kts around Edmonds/Kingston, 7kts closer to Seattle. Port Townsend is only 30nm away... Had a friend in PT that day and they told me it was especially smelly up there.

AndrewM said...

It's back.

This wind map:
http://old.sailflow.com/windandwhere.iws?regionID=119
shows winds @ NW 12 at Pt Townsend and N 12 at Hansville.
That would put the paper mill just about 2 hours upwind from me.

Dan said...

Perhaps decomposing macro algae in Puget Sound and resulting generation of hydrogen sulfide gasses? See http://www.psparchives.com/publications/our_work/science/blooms_report.pdf

Paul said...

Thank goodness it wasn't zombies. I always hate that when zombies come trudging out of the fog.

BeHappy! said...

On a side note: I noticed this smell in Tukwila on Jan 3rd. As we were entering the mall at 7pm my friend and I both said something smelled like a pulp mill (Tacoma aroma). So maybe it wasn't just last night?

zig zag said...

After living in the area for just under 2 years. Yesterday morning was the first day 1/7/2015 that I noticed an obvious absence of nature sounds. Not a bird ,squirel, dog bark, neighbors chickens clucking or even a tree frog. I live in the woods in Poulsbo. I did notice the papermill stink though. The thought of an earthquake immediately came to me , having heard that animals will respond to them this way. Very creepy. The release of atmospheric methane gas due to seismic activity might be to blame. Fog seems unlikely since it stank again in Bremmerton this afternoon. Clear skies. No fog today. Would'nt it be nice if we could trust the powers that be about any expaination given.

db said...

Like a previous poster, I had 4 different people comment to me about the aroma as well. Like him, three said it smelled like a pulp mill. Or worse. One said he liked it. And said futher, if I didn’t like it I should move. Back to where I came from. There’s no come back for that.

Greg said...

I'm a few miles sw of Port Orchard and it was bad.

Nadine MacLane said...

Nothing to notice in bothel or redmond, I'm not sure about the cow theory

Devin Thomas Regney said...

Professor Mass,

It is possible that the smell was influenced by the decomposition salmon from this past fall. If you've ever walked the river after a Pink salmon run, you would fully understand where I'm coming from.

wavelength said...

the stink was in: seattle, tacoma, port orchard, poulsbo, bainbridge. but not in bothell,bellevue and kirkland (where i live)--cow odors from eastern king county would not have jumped over bothell and bellevue.
i think it was colonel mustard in the library.

ksausman said...

We had the smell all morning here on Lopez island, SLC. We thought it was low tides. We have smelt this before. But it seemed stronger then before.

Fan of Dr. Mass said...

Yes to the Lopez Islanders. It was also sensed strongly at southern tip of San Juan Island, this morning, Friday. I thought: "eau de pulp mill" creeping in from somewhere, and due to inversion. It had gone by about 10:30 AM.

Blake said...

I live in N Seattle near Carkeek Park. I have smelled the treatment plant there many times during inversions like this. It did not smell like that to me. I also lived in Salem OR years ago. The odor was exactly like the pulp mill on I-5 between Salem and Corvallis. I'm voting pulp mill for sure.

Barbara Hinsz said...

I left my office near Green Lake 10PM and it was stinky and foggy. Sewage and low tide immediately came to mind. Half hour later when I got home, it was still foggy, but no stink. I live east of Lynnwood and west of Mill Creek.

Ken Cousins said...

Just stepped outside in Ballard (January 25th), and the smell is back.

Sherry M said...

Just moved to hansville and researched the stench before moving here and found this:
Port Townsend Paper Corp. mill gets permit to add two pulp ...
www.peninsuladailynews.com/.../NEWS/30724998...

The Port TOWNSEND PAPER MILL got permission to add two more smoke stacks increasing polution by 3%. The fog here stinks to high heaven.

Sherry M said...

Port Townsend Paper Corp. mill gets permit to add two pulp ...
www.peninsuladailynews.com/.../NEWS/30724998...

It's the pulp mill!