Alaskan Volcano Pavlof Erupting

November 16th, 2014 by Roy W. Spencer, Ph. D.

One of the most active volcanoes in the U.S., Pavlof, has been erupting in a remote section of Alaska’s Aleutian Islands over the last couple of days. MODIS satellite imagery shows the ash plume, estimated to be 35,000 ft in altitude, blowing northwest from Mt. Pavlof out over the Bering Sea.

Eruption of Alaskan Volcano Pavlof on Nov. 14-15 as seen from the NASA MODIS satellite imager.

Eruption of Alaskan Volcano Pavlof on Nov. 14-15 as seen from the NASA MODIS satellite imager.

In the second image above (from yesterday), the high-altitude ash cloud casts a shadow on the low clouds below it.

Here’s what last year’s eruption of Pavlof looked like as viewed from the International Space Station.

2013 eruption of Pavlof as seen from the International Space Station.

2013 eruption of Pavlof as seen from the International Space Station.

Pavlof is a stratovolcano, the type which can produce explosive eruptions, which in rare instances leads to temporary global cooling if enough sulfur is ejected into the stratosphere. It is not known how long Pavlof will continue to erupt, but it has been quiet for the last several hours.

Details and near-realtime monitoring can be found at the Pavlof page of the Alaska Volcano Observatory.


10 Responses to “Alaskan Volcano Pavlof Erupting”

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  1. jimc says:

    Sulfur (SO2?) is a visible reflector as opposed to an IR reflector?

    • It is a visible reflector, but also an IR absorber. The Earth Radiation Budget Satellite (ERBS) measured a 2%-4% increased reflection by the sulfate aerosols after the 1991 eruption of Pinatubo, but it also measured the decreased IR emission because the aerosol layer in the lower stratosphere was blocking the warmer IR emission from below. The solar reflection effect dominates, which is why volcanoes cool.
      The increased IR absorption by the aerosol layer leads to a dramatic warming in the lower stratosphere after a major eruption.

      • Andrew McRae says:

        That means aerosols cause a vertical redistribution of energy in the atmosphere. Given that CAGW is a proposition about surface air temperature, does that mean aerosols count as a warming effect from the myopic CAGW perspective even if their net effect on the planet in total is one of cooling?
        (i.e. an accounting trick)

        • jimc says:

          Pinatubo was big and near the equator (lots of light), this one is smaller and remote in the winter hemisphere (less light). I assume the effect will be nil (except maybe Arctic ice next year, if the aerosols hang around that long)?

  2. ren says:

    “Response of Cloud Condensation Nuclei (> 50 nm) to changes in ion-nucleation.
    n experiments where ultraviolet light produces aerosols from trace amounts of ozone, sulphur
    dioxide, and water vapour, the number of additional small particles produced by ionization by
    gamma sources all grow up to diameters larger than 50 nm, appropriate for cloud condensation
    nuclei. This result contradicts both ion-free control experiments and also theoretical models that
    predict a decline in the response of larger particles due to an insufficiency of condensable gases
    (which leads to slower growth) and to larger losses by coagulation between the particles. This
    unpredicted experimental finding points to a process not included in current theoretical models,
    possibly an ion-induced formation of sulphuric acid in small clusters.”
    http://arxiv.org/pdf/1202.5156.pdf

  3. ren says:

    Thank you, Dr. Roy Spencer, that you are firmly in reality.

  4. I like Dr. Spencer’s explanation to the question that was presented. Excellent.

  5. Edward says:

    We are coming off of several of the coldest winters in the NYC area. Warmers said there would be no snow in the U.S. by around 2014. Yet, it’s been colder and snowier the last few years. When do you admit that Warmers are wrong about this? Warmers never admit they are wrong but instead use ridicule to try to silence their critics. Now there’s good science for you – ridiculing informed critics.

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