Volcanic activity « CIMSS Satellite Blog

Eruption of the Nabro volcano in Eritrea

June 14th, 2011

FY-2E 0.73 µm visible channel images (click image to play animation)

The Nabro volcano erupted in the northeast Africa country of Eritrea on 12 June 2011. An oblique view using the Chinese FY-2E satellite (positioned over the Equator at 105º East longitude) 0.73 µm visible channel data (above; click image to play animation) showed the volcanic plume streaming northwestward on 13 June (the Nabro volcano is located near the bottom center of the images. Note that the plume became much brighter on the visible images later in the day, due to forward scattering.

A sequence of EUMETSAT Meteosat-9 7.35 µm “water vapor channel” images (below; click image to play animation) was useful for following the leading edge of the volcanic plume (the volcano summit is circled on the first few images of the animation). The plume moved northward over far northeastern Africa, and eventually curved anticyclonically and passed over the northern Arabian Peninsula on 14 June. It then appeared as if the leading edge of the volcanic plume might have eventually become entrained into a conveyor of isentropic ascent, where moisture began to increase (exhibiting a darker blue color on the water vapor images).

Meteosat-9 7.35 µm water vapor channel images (click image to play animation)

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Puyehue-Cordón Caulle volcanic eruption in Chile

June 5th, 2011

GOES-12 0.65 µm visible channel images

An explosive eruption of the Puyehue-Cordón Caulle volcano in Chile occurred on 04 June 2011. GOES-12 0.65 µm visible channel images (above) showed a darker gray ash cloud punching above the meteorological cloud deck around 18:15 UTC, with the ash cloud quickly spreading southeastward and moving over Bariloche, Argentina (station identifier SAZS).

A comparison of GOES-12 3.9 µm shortwave IR and 10.7 µm IR window channel images (below) revealed a pronounced and persistent “hot spot” signature (dark black pixels) at the summit of the volcano on the shortwave IR images — while the long and narrow cold high-altitude volcanic cloud (exhibiting IR brightness temperatures around -60º C, darker red color enhancement) could be seen spreading southeastward for a great distance on the IR window images.

GOES-12 3.9 µm shortwave IR (top) and 10.7 µm IR window (bottom) images

CIMSS activities in the GOES-R Proving Ground include the generation of real-time volcanic ash retrieval products (using Meteosat SEVIRI data as a proxy for GOES-R data), which showed a significant volcanic ash plume emerging over the Atlantic Ocean (below).

SEVIRI volcanic ash retrieval products

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Eruption of the Grímsvötn volcano in Iceland

May 21st, 2011

Meteosat-9 visible channel images

Meteosat-9 visible channel images (above) showed the volcanic eruption cloud emanating from the Grímsvötn volcano in Iceland on 21 May 2011 (images courtesy of Dave Santek, SSEC). According to the Icelandic Met Office, at 21:00 UTC the eruption plume had risen to an altitude of over 65,000 ft (~20 km). It is interesting to note that the London VAAC reported

EXTREME LIGHTNING ACTIVITY DETECTED BY ATDNET SYSTEM OF UK METOFFICE, 7000 BETWEEN 1900Z AND 0100Z

The volcanic eruption cloud was even apparent on the very edge of GOES-13 (GOES-East) imagery, as can be seen in an animation of visible channel images (below). The oblique viewing angle from this satellite helped to emphasize the large vertical extent of the eruption cloud.

GOES-13 visible channel images

An animation of Meteosat-9 SEVIRI volcanic ash retrieval product 4-panel images (below) indicated that the initial volcanic cloud was ice-dominated (darker red color enhancement on the false color Red/Green/Blue or RGB images in the upper left panel). Around 22:00 UTC, the signal of an SO2 cloud (green color enhancement) began to appear around the northern and northeastern edges of the eruption cloud — very high values of SO2 were subsequently seen moving northward, using data from the OMI instrument.

A more distinct volcanic ash signal (pink color enhancement on the RGB image) became obvious as time progressed along the southern and southeastern edges of the eruption cloud, and by 06:00 UTC on 22 May the retrieved maximum ash height had reached 7.52 km (with the mean volcanic ash particle effective radius at 11.14 µm). Total volcanic ash mass loading had increased to 44.97 kilotons by 06:00 UTC.

Meteosat-9 volcanic ash retrieval 4-panel images

CIMSS participation in GOES-R Proving Ground activities includes the generation of these SEVIRI volcanic ash retrievals, which offers a demonstration of the type of products that will be available for volcanic ash monitoring with the ABI instrument on the future GOES-R satellite.

===== 22 MAY UPDATE =====

Meteosat-9 visible channel images (below; click image to play animation) showed that multiple volcanic eruption clouds were still reaching significant vertical heights, with much of this high-altitude material drifting northward. Another lower-altitude hazy volcanic ash cloud could also be seen spreading out just off the southern coast of Iceland. See the US Air Quality blog for MODIS true color images and OMI SO2 images of the volcanic eruption.