Having A Weird Winter? It's Not Climate Change

The biggest problem with the constant harping about the climate and all the restrictions and protests going on is that people seem to have forgotten that there's this thing called "weather" and weather changes for a winter or summer or even for a few years has little to do with climate.  Climate is a long term average, although pinning down the definition of "long term" can be dicey (to me it has to be more than 30 years, maybe 50 years).  There are places that alternate dry periods with wet periods, for example, so that no year ever actually matches the climate numbers.  Add to it the human tendency to remember unusual or extreme events and you get people saying "it snowed more when I was a kid and we haven't had snow in three years - it's the climate!"  In reality, it could be that they remember their childhood snowy days because they were exciting (no school!) and in any case weren't alive long enough to know if it snowed like that regularly.

Where am I going?  Why the lead in? 

Back near the end of last July, I passed along a story that I'd read about the monstrous underwater volcano called Hunga Tonga-Hunga Ha'apai that erupted over a year and half before then, on January 15 of '22.  Within a week of the eruption it was being noted as one of the most violent eruptions ever seen, with this startling statement from a group that monitors nuclear explosions. 

Titled “A nuclear-test monitor calls Tonga volcano blast 'biggest thing that we've ever seen',” it reports that an international group that monitors for likely atomic detonations has reported that at every one of their sites around the world - 53 of them - the infrasonic wave from the Tongan volcano is the largest thing they've ever measured, even bigger than the Soviet Union's Tsar Bomba, the biggest nuclear detonation in history. [BOLD added - SiG]

The point of that article was that the volcano (which I've come to call just Hunga-Tonga - which is probably violating all sorts of protocols) injected three times more water into the upper stratosphere than was originally estimated.  It injected 150-million metric tons or almost 40 Trillion gallons of water vapor into the atmosphere.  The concern expressed then was that water vapor is a potent greenhouse gas and it was going to affect the weather for years.  How big an effect and for how long?  See the part about "most violent eruptions ever seen" - nobody had any real experience to base calculations on. How can anyone trust a model that has never been verified with this sort of situation?

The story has deepened yet again.  Watts Up With That published a story this morning linked to the NOAA Research hub saying that changes have been induced in the atmosphere unlike any ever measured before.  The eruption caused an enormous decrease in stratospheric ozone levels. 

“Our measurements showed that stratospheric ozone concentrations decreased rapidly – by as much as 30% in air with the highest water vapor concentrations – in the immediate wake of the eruption,” said Stephanie Evan, a scientist from the Laboratoire de l’Atmosphère et des Cyclones in France and lead author of the other recent study, published in the journal Science. Evan and colleagues continued to measure ozone concentrations depleted by around 5% across the Indian and Pacific oceans two weeks following the eruption.

This graphic depicts how the ejection of water vapor from Hunga-Tonga volcano accelerated ozone depletion in the stratosphere. Credit: Chelsea Thompson/Chemical Sciences Laboratory

Volcanic aerosols are profoundly important for global climate, as demonstrated by the 1991 Mt. Pinatubo eruption that cooled the planet by 0.5°C (0.9°F) for nearly two years. They can also act as surfaces upon which rapid chemical reactions can take place, leading to the destruction of ozone.

By combining data from the balloon measurements with global satellite data, [Elizabeth] Asher and colleagues found that a large, dense layer of aerosol particles formed in the stratosphere faster than had ever been seen before. These findings were published in the Proceedings of the National Academy of Sciences.

“The tremendous amount of water vapor that this volcano sent to the stratosphere led to a rapid production of sulfate aerosol particles that we were able to observe within days of the eruption,” explained Asher. Under normal atmospheric conditions, sulfate aerosols form from sulfur dioxide on a timescale of about a month. In this case, rapid measurements provided critical clues for determining the chemical and microphysical processes required to cause these effects – clues that would have vanished if the measurements had been taken a month later.

Just based on the 40 Trillion gallons of water vapor injected into the stratosphere, I think it's likely that temperatures around the globe will be higher than they normally would have been for another couple of years.  While I never heard anyone acknowledge this, during last year's hurricane season, I heard a lot of stories about about warmer sea surface temperatures than expected, and I assumed this was an effect of the Hunga-Tonga eruption.  

How - or even if - the Hunga-Tonga Ozone Hole will affect temperatures hasn't been addressed in the reference articles.  The important point is that all of the effects of the Hunga-Tonga eruption broke the models used to understand these things.  The scientific understanding of aerosol processes in the stratosphere remain one of the largest sources of uncertainty in climate predictions.  Anything you hear about climate, warming, and all that media hype needs to be considered in light of natural events like Hunga-Tonga.