So Far, It Looks Like Tonga Volcano Won't Cool Earth, But Atmospheric, Ocean Effects World Wide Entire World's Atmosphere

The volcano exploding in Tonga last weekend. Its effects were
felt around the world, but the eruption is unlikely to
cause any noticeable global cooling. 

 We have a bit more data and some incredible stats from that volcano that blew up in Tonga Saturday.

When I first posted about this volcano, I wondered if the ash and sulfur and stuff that billowed all the way up into the stratosphere would have an effect on global climate.  Large quantities of sulfur injected into the stratosphere would tend to temporarily cool the Earth's climate.  

The huge eruption of the Pinatubo volcano in the Philippines back in 1991 pushed enough sulfur into the stratosphere to cool the world by about a degree Fahrenheit for a year or two. An even bigger volcanic eruption in 1815 cooled the world even more dramatically, with cold and disastrous results. 

According to the Washington Post, satellite data analyzed over the weekend suggest the Tonga eruption had only about 1/50th of the impact of Pinatubo, which means Saturday's blast would only cool the world, or counteract continued global warming, but 0.02 degrees Fahrenheit. In other words, basically too small to notice.

That said, if the Tonga volcano keeps erupting, it could belch more and more sulfur into the stratosphere to the point where it could have a noticeable, though temporary effect on climate.

ATMOSPHERIC/OCEANIC REVERBERATIONS

Even so, that Tonga blast was mighty. One estimate is the blast had 14,000 times the yield of the atomic bomb that destroyed Hiroshima.  So of course the Tonga last was felt  one way or another around the world. First, let's go to the source, right at the blast site. Volcanic eruptions often produce lightning, but Tonga was off the charts. Lighting detection equipment detected 60,000 strikes or 70 lighting strikes per second in the first 15 minutes following the blast, says the Washington Post. 

I was stunned yesterday to read the volcanic blast was heard 1,500 miles away in New Zealand. It turns out, the shock wave generated a booming noise in Alaska, 5,000 miles away from the volcano. Hawaii is closer to the volcano and nobody reported noise there, so there must have been some sort of weather situation in Alaska that made it audible. 

Climatologist Brian McNoldy (@BMcNoldy)
posted this graph showing five atmospheric pressure
jiggles from Tonga volcano shock waves passing
over Miami. The lowest one on the bottom,
labeled in yellow, was not a volcano shock wave
but rather a strong cold front passing through. Click
on the image to make it bigger and easier to see.

Tsunamis from the volcano were detected pretty much all over the world. Some of them were surprisingly large. In Peru, the tsunami killed two people and caused a lot of flood damage along the coastline. 

The tsunami created a four-foot spike in water levels at Port San Luis, California, 3.5 feet at Arena Cove, California, 2.7 feet at Crescent City in northern California and 2.8 feet in King Cove, Alaska, reports the Washington Post. 

There are actually two types of tsunamis.  The most familiar -  and dangerous  - ones are caused by earthquakes and volcanoes. Another type, meteo-tsunamis are triggered by abrupt changes in weather, such as a sudden air pressure rise or fall or very quick changes in wind speed or direction. 

The Tongo volcano produced both types of tsunamis all the way over in the Caribbean Sea, though anyone standing on a beach there probably wouldn't have noticed. But instruments did detect the tsunamis. 

About 24 hours after the volcanic explosion, the tsunami directly caused by the event had rounded the base of South America, and spread out in a subtle fashion across the Atlantic Ocean into the Caribbean. 

In Martinique, the tsunami amounted to about a 0.2 meter, or nearly eight inch shift in water levels. But half a day before that the water levels at Martinique beaches wiggled much more modestly.  That was caused by air pressure changes created by the shock wave in the air created by the volcano.

The atmospheric shock wave circled the globe more than once. It went all directions of course. The eastbound one crossed the United States and was measurable across the nation, reaching us here in Vermont at around 11 a.m. Saturday. 

The westbound edge of the shockwave crossed Asia, Europe and the Atlantic Ocean, reaching us here in New England late Saturday night.  Then it continued westward across the nation again.

For some reason, the air pressure changes with that second one were a little bigger than the earlier one in Vermont/New England, despite having traveled a much larger distance.  I'm not sure why, and I haven't found any credible source that would explain why.

One guess is that the shock wave had traveled all the way across the Atlantic and was not disrupted by mountains and other terrain.  Or, the air over us late Saturday was especially cold and dense, which could have left the atmosphere more prone the disturbance caused by the shock wave.   

In Miami, sensitive barometers have recorded air pressure jiggles five times as the remains of those shock waves orbit the Earth. 

In one instance, in Seattle, the atmospheric perturbations probably briefly changed the weather. A thin temperature inversion had the Sea-Tac airport fogged in.  When the shock wave arrived, the fog cleared briefly, apparently because the pressure change disrupted the temperature inversion.  Once the shock wave passed and the barometric pressure stabilized, the fog came back. 

TONGA ITSELF

An island in Tongo covered in ash from the massive volcanic
eruption last week. Photo by Vanessa Parker/AP

The volcanic blast obliterated the island it was on. Worse, reports are finally trickling in about the effects elsewhere on this multi-island nation and the news is quite bad. 

As NBC News reports, international phone lines and the internet are still down in the region, so it's hard to get a grasp of what's going on along Tonga's chain of islands.

We do know at least three people died in the large tsunamis that swept Tonga, in addition to the two who died in the smaller tsunami in Peru. Thick ash turned the normally verdant landscape brown. Scores of buildings along the coasts have been swept away.  A reconnaissance flight over one island showed a collection of about 50 houses had been entirely swept away. 

 

 

Massive Tonga Volcanic Eruption Also Has Meteorological, And Possibly Global Climate Effects

Satellite view of massive volcanic eruption in 
Tonga today. Depending on how much ash and
other material the eruption put in the stratosphere,
this could have some slight, temporary cooling 
effect on the global climate 

 If you hadn't heard, there's a lot of breaking news this morning about an incredible volcanic eruption in Tonga. 

Tonga is a chain of island in the southwestern Pacific Ocean. There, an underwater volcano has been erupting. There was a large eruption Friday, then Saturday, an immense one.  This is surely the most powerful explosion the world has seen in decades, possibly centuries. 

It immediately produced an immense cloud of ash, a shock wave that traveled thousands of miles and tsunamis that are in one form or another affecting the the entire Pacific Ocean basin, all the way to the United States and Canadian west coasts. 

That's impressive, given that Tonga is about 8,600 miles from Los Angeles. Any tsunami activity on the West Coast will be relatively minor. No big waves smashing into buildings, but it is too dangerous this morning to be hanging out on the water or right on the beach. Tsunami waves as high as 2.7 feet have already been reported in Hawaii. 

Relatively small tsunamis then hit the United States west coast, causing some damage in California mostly to boats and cars parked at marinas. 

More destructive tsunamis have hit islands in and near Tonga.

So far, I've discussed geology and oceanography, not meteorology and climate, which is the point of this blog. But the eruption has had or might have effect on both those sciences.

The explosion was so huge it sent shock waves through the atmosphere far and wide. People in New Zealand, about 1,500 miles from the eruption, heard booms and rumbles from atmospheric shock waves generated by the explosive volcano. Barometric pressure in New Zealand wiggled up and down. This morning, barometers registered tiny, but abrupt changes in air pressure that moved west to east across the nation.

Those barometric wiggles were noticed here in Vermont shortly before 11 a.m. today. 

To give you an idea of the scale of this, had the Tonga explosion occurred in Miami, we would have heard the boom and rumbles from it here in Vermont. 

There's a chance this eruption could cause a bit of global cooling.  We probably won't know for weeks what effect the eruption will have on the global climate, if any. 

We do know the explosion was big enough to loft ash, sulfur and other stuff into the stratosphere, which is the layer of the atmosphere above where most weather occurs.

From there, the gunk from Tonga would be swept across nearly the entirety of the stratosphere above Earth.  If there's enough stuff up there, it could cause temporary global cooling.  

A tsunami washes over a Tonga island after a massive
volcanic eruption in the southwestern Pacific Ocean today

A huge eruption of the volcano Pinatubo in the Philippines back in 1991 cooled the world by about 1 degree Fahrenheit for a year or two, and temporarily putting the brakes on global warming.

An even worse volcanic explosion in 1815 spewed so much stuff into the atmosphere that the Earth cooled dramatically.  It caused the infamous Year Without A Summer in 1816 in North America and Europe. (There were hard freezes every summer month in Vermont that year, and snow drifted up to 20 inches deep in Danville during early June).

So far, there's no indication that things will get this dire worldwide from the Tonga eruption. One thing that might have helped is the eruption was partly under the sea, which might have contained some of the ash and sulfur.

How much this eruption cools the world, if at all, will also be the amount and combination of ash and sulfur there is.  If it's mostly ash up there, that will rain out of the atmosphere pretty quickly and not have much of an effect. If there's a lot of sulfur, that would have at least a one to two year cooling effect.

Another question is if this volcano has a series of similar explosions like today's a whole bunch more gunk will end up in the stratosphere, which would have a more pronounced effect on the global climate.

Regardless of what happens, this doesn't cancel climate change. It's possible it could slow or even stall climate change temporarily. Then climate change would come roaring back and quickly rise to levels the atmospheric warming would have had without the volcano