April 17, 2010

Eyjafjallajökull (Iceland Volcano): No Climate Impacts. Local Weather Update

A few media outlets are starting to talk about a climatic impact of the Iceland volcano, but they shouldn't be. First, this is really a pretty modest event. But even more important, it is NOT ejecting large amounts of sulfur dioxide into the stratosphere, which is the main way volcanoes alter climate. As noted in my last blog, sulfur dioxide combines with water vapor to create small sulphuric acid particles that scatter some of the sun's rays back into space. The result is global cooling--up to a degree or two C for the big eruptions.

We have satellites that can measure sulfur dioxide (SO2) from space, one of them being the NASA OMI instrument on its AQUA satellite. Here is a recent image showing total SO2 in a vertical column--no real evidence of volcano SO2 in this and previous images.

In contrast, here is another image from an Alaskan (Aleutian chain) volcano

that had much more prodigious SO2 production. Lots of red...that means plenty of SO2.

Another point is the latitude of the eruption: being far north limits that ability of the SO2 to spread into the equatorial zone and the southern hemisphere.

I suspect the authorities in Europe are being conservative, perhaps too conservative, in canceling flights and closing airports. With some effort, the altitudes and locations of the dust cloud could be accurately delineated and flights could simply be vectored away from the areas of higher concentrations. Furthermore, a lot of the dust coverage over Europe is very thin--is that REALLY a problem for a jet engine? This is really a minor eruption and it seems unlikely that it could spread a sufficiently dense layer of dust over the volume of air in which air traffic restrictions are taking place.

They are being careful, and lets face it, aviation authorities over Europe don't have much experience with such dust events. Long range weather predictions indicate the later in the week the flow over most of Europe will turn more southwesterly, so even if the volcano is going wild most European airports should be functional.

Perhaps some old prop planes (driven by gas engines and not turbines) can be taken out of storage...they do much better with volcanic dust, since the blades of jet turbines are the real vulnerability in volcanic dust clouds.

Want to see an example of an old prop plane flying close to a major eruption? A few hours after the initial Mt. St. Helens eruption, Professor Peter Hobbs and Research Scientist Larry Radke took a UW research aircraft (prop plane) up to and into portions of the volcanic cloud...and lived to tell the tale. You can watch some video of their daring flight: http://pluie.atmos.washington.edu/movies/msh_sm.wmv

Finally, for those of us in the Northwest, tomorrow should be a splendid day. The front is moving through now and the showers are lessening. We should see sun and temperatures climbing into the 60s for the lowlands. Some people has asked whether some of the dust on their cars is volcanic dust. The answer is no. Most of the gunk is pollen from trees and plants. I had to wash my car yesterday...it was covered with the stuff!


  1. Thanks for the lesson! : )

    Regarding the grounding of flights - I found this interesting: http://news.bbc.co.uk/2/hi/8621992.stm

    Glass sounds like a bad thing in jet engines..


  2. Thanks for the fascinating Mt. St. Helens video, Prof. Mass!

    I wonder if that was the UW's old Douglas B-23 they flew in? A 1930s-era medium bomber based on the famous Douglas DC-3 airliner.


    Not sure it would be too easy to wedge in a few hundred folks and head off across the Atlantic non-stop... ;^}

    Bob ^,,^

  3. I think saying that "propeller" airplanes do much better in volcanic ash is giving credit to the wrong part of the airplane. Something like saying this-or-that storm proves/disproves global warming. :) :)

    I believe it's the type of engine powering the airplane that makes the difference. Turbine engines do very poorly in ash, piston engines can handle ash for a while. Virtually all commercial passenger airplanes of any size have turbine engines, including propeller driven "commuter" size airplanes. It would be impossible to find enough piston engine aircraft to move more than a handful of people.

  4. I am not sure if they are being to conservative at $200 million a day lost up in ash. As far as prop planes you are right. They do pretty well on flight hours over wildfires. DC-6’s, King King Air 200’s, PBY, S-2’s and others have great track records flying through ash filled sky’s. (mind you,wood ash is a different beast that they are facing now,though I have seen some prop intakes return to base filled with small twigs being injected into the air from strong column driven fires). Even the Evergreen 747 supertanker now being deployed on fires has been retrofitted for “particle impact” on the intake fans. Maybe the airlines should give them a call...

  5. Turboprops are now standard on many Air Tankers including California's tanker fleet.

  6. OK, no SO2, what about CO2? Is that adding to our worries?

  7. I don't think the European aviation authorities are being overcautious; while it costs the airlines a fortune to NOT fly, it's also extraordinarily expensive to replace damaged jet engines... in one case, volcano-damaged jet turbines cost an airline $80 million after just a single flight through ash.

    The weather people in the UK are actually being blasted for their work on the ash cloud's scope. Airlines conduct more test flights on ash cloud safety (BBC)

    The impact to jet engines by volcanic ash is nicely summarized here: Volcanic ash incidents involving airliners (BBC)

  8. I don't know how accurate this infographic is, but it is interesting:


    Comparing the amount of CO2 released by European aviation on a daily basis vs the volcano itself.

  9. People have been able to sit in their gardens enjoying the spring sunshine without the whine of jets passing overhead from early morning until late at night. The skies are peaceful and cleaner. Some people have reported hearing an unusual tweeting sound – but this comes from birds!

  10. According to the photos shown on boston.com, at http://www.boston.com/bigpicture/2010/04/more_from_eyjafjallajokull.html, there is apparently considerable lightning within the volcano. What causes this?


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

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