June 07, 2023

The Worst Air Quality in New York History?

A historic meteorological/air quality event is now occurring over the New York metropolitan area.

And as far as I can determine, this is the worst air quality event ever recorded there over the past 70 years, the result of smoke from large wildfires in northern Quebec.  

Certainly, the worse air quality ever observed during the warm season in the region.

The real-time cam image of New York City around 1 PM PDT is stunning (see below)


And the high-resolution MODIS imagery reveals the area of dense smoke over the Big Apple:


When I checked the small particulate levels (PM2.5, the concentration of particles smaller than 2.5 microns--millionth of a meter), using the PurpleAir network, I could not believe my eye..values of 300-450 micrograms per cubic meter.


And a plot of PM2.5 from an official site in Queens, NYC shows levels getting to around 800 micrograms per cubic meter...just unheard of.


The weather situation has been perfect to pull the Quebec smoke into the New York area.  Why?   Because of a strong low-pressure area just off the NE coast (see map below at around 5000 ft).  I have added a red arrow to show the low-level wind flow.


The NOAA HRRR Smoke model clearly shows the circulation of the smoke around the low:


So why have we gotten into the early season wildfire situation in northern Canada?

Because the atmosphere over North America has been in an unusual, persistent configuration, with a ridge of high pressure over Canada and a trough of low pressure over California (the figure below shows the situation around 18000 ft for the past month).  Red indicates much higher than normal heights, which are associated with warmer temperatures at low levels, blue indicates lower-than-normal pressure (troughing).


A similar pattern has been in place over the last 90 days (see below).


The high pressure resulted in unusual warmth and drying of the surface fuels.

Is there any reason to think that this configuration is the result of global warming/climate change?  Current research suggests no.

17 comments:

  1. Really, current research suggests no link to climate change? I wasn't aware that attribution studies had been conducted already. Could you point us to the research relevant to this current event?

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    1. There is a lot of research that does NOT find an amplification of jet stream waviness under global warming. I have talked a lot about these studies in this blog. Just do a search through the blog and you will find them...including some of my published work. I am NOT talking about attribution studies for this event.

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    2. Should Google the great fire of 1910 AnotherGuy, no single fire has compared since, strictly burn acres though.. not loss of life or structures. 3 million acres burned

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    3. The Great Fire of 1910 has a strong legacy even today. The aftermath of that fire intensified the Forest Service's approach toward not letting fires burn and cemented this mindset. Fire suppression, prevention, and protection of private property were the goals. So here we are now, 113 years later with forests that have huge fuel loads and ready to combust. I also read that President Taft sent troops to fight this fire in the Northern Rockies. Amongst them were several companies of the reknown Buffalo Soldiers. With their arrival in Idaho, they almost doubled the black population living there at that time.

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    4. I remember when the air in the New York metropolitan area looked this bad every day.

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  2. Isn't the important question whether the fires themselves are more likely due to climate change?

    Of course no specific event (such as a fire or a heat wave or a rain shower) can be proven to result from climate change (or from a specific event such as my Memorial Day BBQ), but are increasing temperatures resulting in more and bigger fires?

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    Replies
    1. The slow warming of the region probably made a small contribution but the key factor was the big ridge, which can not be assigned to climate change.

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  3. The Northeast really doesn't have the climate characteristics for massive wildfires. Maybe a further exploration of the mechanics that allowed this event to take place might be helpful, as that part of the world tends to be far more humid with consistent precipitation all year. Unlike the PNW which has a clearly defined wet and dry season. If anything, summer is a bit wetter. Only set up for this would be a very dry, very warm winter and perhaps some thunderstorms sparking these fires. If Canada sat under a dome of high pressure all the past winter than it makes a bit of sense.

    The fires are in the Boreal forests, so it's not the hardwood forests on the US side going up.

    ReplyDelete
    Replies
    1. Yes...it was a boreal forest fire. Fire is an important part of the ecology of the region and yes, the big ridge of high pressure helped set up this event.

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    2. It seems that Mother Nature is now the top air polluter. When I grew up, it was always humans.

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  4. I would be interested in knowing how this event compares to the worst wildfire smoke events we have had in the Northwest.

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    Replies
    1. The infamous Mariners vs Athletics in 2020 game was ~230ish AQI for comparisons.

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    2. @Trevor: What's not clear about the PurpleAir map shown above is whether the values provided are the AQI calculated by the devices or whether those are actual raw measurements of PM2.5 (µg/m3). If those are the raw particulate measurements, the actual AQI will be much higher than the numbers shown on the map. As a note, my raw PM2.5 measurement right now is around 6.3 µg/m3, but the AQI calculated by my device is 27.

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    3. @time2lose PurpleAir network displays in AQI

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  5. This is from over 200 years ago:

    "New England's Dark Day occurred on May 19, 1780, when an unusual darkening of the daytime sky was observed over the New England states and parts of eastern Canada.The primary cause of the event is believed to have been a combination of smoke from forest fires, a thick fog, and cloud cover. The darkness was so complete that candles were required from noon on. It did not disperse until the middle of the next night."
    https://en.m.wikipedia.org/wiki/New_England%27s_Dark_Day

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  6. So if that is a low up there in Canada, why isn't it giving those poor guys the rain they need to get this knocked down and wash out the smoke? That is what lows do, right?

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

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