The Mount Etna volcano — the tallest on the European continent, and one of the most active in the world — experienced an eruption on 23 November 2013. EUMETSAT Meteosat-10 0.75 µm visible channel images (above; click image to play animation) showed the explosive development of the volcanic plume beginning around 09:30 UTC; the plume then moved rapidly northeastward across far southern Italy, eventually moving over Albania around 13:00 UTC. A number of lightning strikes within the billowing ash plume can be seen in an HD-quality YouTube video.
Mt. Etna, on Sicily in the Mediterranean Sea, erupted early in the morning on Nov 17th just before a Suomi/NPP overpass. The VIIRS Day/Night Band gives a clear view of the volcanic plume (and the light emitted by the lava in the caldera); thermal channels show a distinct hot spot: 360 K in the 11 micron channel, and 523 K in the 3.9 micron channel! (Imagery courtesy Will Straka, UW-Madison/CIMSS)
GOES-15 0.63 µm visible channel images (above; click image to play animation) showed a distinct hazy plume streaming southeastward from the Katmai volcano area in Alaska on 22 September 2013. This was a signature of re-suspended volcanic ash — a deep layer of ash has remained on the ground near the volcano following the massive 1912 eruption — which was carried aloft by strong winds on the back side of a deep area of low pressure over the Gulf of Alaska (below).
A closer view using a sequence of four Suomi NPP VIIRS 0.7 µm Day/Night Band images (below) showed the evolution of the ash plume as it moved over southeastward over Kodiak Island and then out over the Gulf of Alaska. Winds at Kodiak (station identifier PADQ) gusted as high as 55 knots or 63 mph. With limited snow cover and strong winds (which were enhanced by local terrain effects), the surface volcanic ash was easily lofted to great heights.
An image of a MODIS-based NOAA/STAR/CIMSS Volcanic Ash Height product is shown in combination with the Volcanic Ash Advisory that was issued by the Anchorage Volcanic Ash Advisory Center (below).
A sequence of three MODIS Volcanic Ash Height product images (above) suggested that the average height of the re-suspended ash plume was around 9,000 – 11,000 feet. A vertical profile of CALIPSO satellite-based lidar data near the source of the ash plume (below; courtesy of Mike Pavolonis, NOAA/NESDIS/STAR) indicated that the top of the plume was around 3.5 km or 11,000 feet (at 12:57 UTC, near latitude/longitude 58 N / 155 W).
The corresponding MODIS Ash Mass Loading product (below) indicated values of 2-3 tons per square kilometer existed over much of the ash plume.
Finally, the corresponding MODIS Ash Mass Effective Radius product (below) showed that much of the plume likely consisted of particles with radii in the 4-6 µm range, with a maximum value of 8.33 µm.
Additional information on the NOAA/UW-CIMSS GOES-R Volcanic Ash Products shown above can be found in this Java-based VISITview lesson (a separate Lesson Playback Control window will open to assist in viewing the lesson content).
===== 23 September Update =====
On the following day (23 September), a Suomi NPP VIIRS 0.7 µm Day/Night Band image (above) showed that the resuspended Katmai ash plume was still present, but was much less expansive than what was seen on 22 September.
Hat tip to Mark Ruminski of the NOAA/NESDIS Satellite Services Division for bringing this interesting event to our attention!
Tungurahua is an active stratovolcano in Ecuador (Wikipedia); a Landsat-8 false-color image showed the partially snow-covered dome of the volcano on 13 July 2013. On the following day, the Washington Volcanic Ash Advisory Center issued a volcanic ash advisory due to an explosive eruption that occurred at 11:51 UTC on 14 July 2013. A GOES-13 false-color Red/Green/Blue (RGB) image created using the NOAA/CIMSS GOES-R Volcanic Ash Detection Algorithm (above) highlighted a warm thermal anomaly and a volcanic cumulonimbus (based upon very rapid cloud top cooling rates and cold IR brightnesss temperature values) minutes after the eruption began — during the “11:45 UTC” GOES-13 image, the satellite was actually scanning the region of the volcanic eruption at 11:58 UTC.
A comparison of the early stages of the volcanic cloud as viewed from GOES-15 (GOES-West), GOES-12 (GOES-South America), and GOES-13 (GOES-East) is shown with visible channel images (above) and IR channel images (below). The actual times that each of the satellites were scaning the region of the volcanic eruption are noted in the labels, and the images are shown in the native projection for each individual satellite.
The GOES-13 satellite was the first to detect to volcanic cloud, since it was scanning the area at 11:58 UTC (about 7 minutes after the beginning of the eruption). The oblique viewing angle from the GOES-15 satellite helped to highlight the darker gray appearance of the ash-laden volcanic cloud, and reveal the long shadow being cast to the west of the tall feature (estimated to be as high as 45,000 feet above ground level). The volcanic cloud appeared largest on the GOES-12 images due to the more direct viewing angle, as well as the later scan time.
Animations depicting the volcanic cloud evolution are shown using GOES-12 0.65 µm visible channel, 6.5 µm water vapor channel, and 10.7 µm “IR window” channel images (below). Since a large amount of water vapor is usually exhaled during such explosive eruptions, the extent of the volcanic cloud can be more easily followed on the water vapor channel images.