Thursday, April 15, 2010

You say Volcano, I say Eyjafjallajökull (Volcano could mean cooling, acid rain)

UPDATE (May 17): Goodbye Eyjafjallajökull, Hello Katla: Big Sister Rumbles
UPDATE (May 7):
Iceland Volcano: "Eyjafjallajökull Update for 5/7/2010"
UPDATE (April 23):
"How to short a volcano" (What did Eyjafjallajökull screw up?)"'
(April 22)
"First, Iceland goes bankrupt. After that, it sets itself on fire. This has insurance scam written all over it."
UPDATE (April 21):
"Eyjafjallajökull chugs along as Europe begins to recover" and Protective Gear for the next Eruption
"It was the last wish of the Icelandic economy that its ashes be spread over Europe"
UPDATE (April 20):
"What Next From Iceland's Volcano?"
UPDATE (April 19)
"Volcanic ash relentless as tremors rock Iceland" and "...Eyjafjallajökull volcano is nothing to 'Angry Sister' Katla"
"Ash Cloud Over Europe May Cost Airlines $1 Billion" (AFR.DE; BAY.L; DAL)"
: "Insurance: "Iceland Volcano Eruption Could Mean Business and Catastrophe Claims"'
Original post:
Here's the BBC's Guide to Icelandic Pronunciation. Pity the poor newsreaders.
As best as I can make out it's something like:


Potential cooling, that's what MSNBC says:

'Not like Pinatubo' so far, but potential is there

If Iceland's active volcano gets even more active, Icelanders and air travelers won't be the only ones impacted. Gases from past large volcanoes have actually lowered Earth's temperatures, triggered lung ailments, caused acid rain and thinned our protective ozone layer.

The Eyjafjallajokull volcano isn't there yet. "This is not like Pinatubo. So far the scale is not big enough to have a global effect," Hans Olav Hygen, a climate researcher at the Norwegian Meteorological Institute, said in reference to the 1991 eruption in the Philippines....

...Other examples of how the environmental impacts of volcanoes can go far beyond their immediate area:
  • In 1783, a poison cloud from the eruption of Iceland's Laki volcano killed thousands of people across Europe and undermined farm output by spewing an estimated 120 million tons of sulfur dioxide into the air, said Colin Macpherson, a geologist at the University of Durham in England. That amount of sulfur dioxide was three times European industrial output in 2006....MORE

Dr. Jeff Masters disagrees. From Wunderblog:

...Iceland volcano not likely to significantly affect the climate or weather
Volcanic eruptions are capable of significantly cooling the climate for 1 - 2 years after a major eruption spews sulfur dioxide gas forcefully enough so that it reaches the stratosphere. Once in the stratosphere, the gas reacts to form highly reflective sulfuric acid droplets mixed with water (sulfate aerosol particles). Our volcanoes and climate page covers the topic in more detail. Let's examine recent volcanic eruptions that have had a significant cooling effect on the climate. In the past 200 years, Mt. Pinatubo in the Philippines (June 1991), El Chichon (Mexico, 1982), Mt. Agung (Indonesia, 1963), Santa Maria (Guatemala, 1902) Krakatoa (Indonesia, 1883), and Tambora (1815) all created noticeable cooling. The Mt. Pinatubo and El Chichon eruptions caused a greater than 10% drop in sunlight reaching the surface. The eruption of Tambora in 1815 had an even greater impact, triggering the famed Year Without a Summer in 1816. You'll notice from the list of eruptions above that all of these climate-cooling events were from volcanoes in the tropics. Above the tropics, the stratosphere's circulation features rising air, which pulls the sulfur-containing volcanic aerosols high into the stratosphere. Upper-level winds in the stratosphere tend to flow from the Equator to the poles, so sulfur aerosols from equatorial eruptions get spread out over both hemispheres. These aerosol particles take a year or two to settle back down to earth, since there is no rain in the stratosphere to help remove them. However, if a major volcanic eruption occurs in the mid-latitudes or polar regions, the circulation of the stratosphere in those regions generally features pole-ward-flowing, sinking air, and the volcanic aerosol particles are not able to penetrate high in the stratosphere or get spread out around the entire globe.

There have been at least two exceptions to the tropics-only rule. discusses the eruption of the Laki volcano in Iceland, between 1783-1784. The eruption was probably not able to inject much sulfur into the stratosphere. However, since the eruption was sustained for so long, significantly elevated sulfur concentrations were seen in the lower atmosphere over much of the Atlantic and European regions, which had a pronounced cooling effect on the region. has an interesting article about the largest volcanic eruption of the 20th century--the 1912 eruption of Alaska's Mt. Novarupta, located in the same chain of volcanoes as Mt. Redoubt. According to a NASA computer model, Novarupta's climate-cooling aerosols stayed north of 30°N latitude, and did not cause global cooling. However, the model indicates that the eruption may have indirectly weakened India's summer monsoon, producing an abnormally warm and dry summer over northern India.

It does not appear that the current eruption of the Eyjafjallajökull volcano on Iceland was large enough to alter the atmospheric circulation of the Northern Hemisphere and cause a change in the late spring/early summer weather patterns. A series of several major eruptions over the next few weeks would be required for that to happen. The volcano is also too far north for the cooling effect of its ash cloud to affect the sea surface temperatures in the tropical Atlantic for the coming hurricane season. However, the ash could should bring spectacular sunsets to Europe over the next week, and to North America by sometime next week, as the jet stream wraps the ash cloud eastwards across the Northern Hemisphere.
While USA Today said it's the OTHER volcano that might be the problem:

Global cooling: What happens if the Iceland volcano blows

The potential eruption of Iceland's volcano Katla would likely send the world, including the USA, into an extended deep freeze.

"When Katla went off in the 1700s, the USA suffered a very cold winter," says Gary Hufford, a scientist with the Alaska Region of the National Weather Service. "To the point, the Mississippi River froze just north of New Orleans and the East Coast, especially New England, had an extremely cold winter.

"Depending on a new eruption, Katla could cause some serious weather changes."

Eyjafjallajokull, the Icelandic volcano that has continued to belch lava, ash and steam since first erupting last weekend, isn't the direct problem. It's Katla, the noisier neighbor, that's the concern. If lava flowing from Eyjafjallajokull melts the glaciers that hold down the top of Katla, then Katla could blow its top, pumping gigantic amounts of ash into the atmosphere.

Scientists say history has proven that whenever the Eyjafjallajokull volcano erupts, Katla always follows -- the only question is how soon.

"If it (Eyjafjallajokull) continues to belch, then you worry," says Hufford.

What's key in having volcanic eruptions affect the weather is both the duration of the eruption, and how high the ash gets blasted into the stratosphere, according to Hufford.

For example, he says, Mount Pinatubo pumped ash for two days in 1991, and spewed it 70,000 feet into the stratosphere. This dropped temperatures worldwide about four degrees for about a year.

"When volcanic ash reaches the stratosphere, it remains for a long time," reports Hufford. "The ash becomes a very effective block of the incoming solar radiation, thus cooling the atmosphere's temperatures."...

See also: "Are all the recent big earthquakes connected? "