Volcanic Eruption on Kamchatka

March 26th, 2015
Himawari-8 Visible (0.64µm) Imagery (Click to animate)

Himawari-8 Visible (0.64µm) Imagery (click to animate)

Infrared imagery from Himawari-8 has a nominal resolution of two km (at the sub-satellite point), but a visible channel has a nominal resolution of 0.5 km which can provide imagery with great detail. In the example above, the visible imagery captures the eruption, beginning around 2210 UTC on 25 March 2015, of the Shiveluch volcano on Russia’s Kamchatka Peninsula. The volcanic plume then moves downstream in northwesterly flow. Himawari-8 remains in post-launch testing, the period when the satellite calibration and navigation is thoroughly checked.

Suomi NPP overflew this region multiple times on 26 March 2015. VIIRS data from a 0126 UTC overpass, below, taken from this website, show satellite-based diagnostics of this event. The animation cycles through a Brightness Temperature Difference (11µm – 12µm), Ash Loading, Ash Height and a False Color RGB presentation of the volcanic plume.

Suomi NPP VIIRS Brightness Temperature Difference (11µm -12µm), Ash Loading, Ash Height, and False Color Imagery, 0126 UTC 26 March 2015 (Click to enlarge)

Suomi NPP VIIRS Brightness Temperature Difference (11µm -12µm), Ash Loading, Ash Height, and False Color Imagery, 0126 UTC 26 March 2015 (click to enlarge)

Update: On 26 March, a Suomi NPP VIIRS true-color RGB image from the SSEC RealEarth site provided a nice view of the Shiveluch volcanic plume (below); also evident on the true-color image (as well as on images from the previous two days) to the north of Shiveluch were a pair of volcanic ash “fall streaks”, where the tan-colored ash landed on top of the existing snow cover.

Suomi NPP VIIRS true-color images from 24, 25, and 26 March

Suomi NPP VIIRS true-color images from 24, 25, and 26 March

GOES-15 also viewed the eruption, at the extreme edge of its limb, as seen on the sequence of 0.63 µm visible channel images below (Shiveluch is at the center of the images).

GOES-15 0.63 µm visible channel images (click to play animation)

GOES-15 0.63 µm visible channel images (click to play animation)

Eruption of the Villarrica volcano in central Chile

March 3rd, 2015
Suomi NPP VIIRS 0.7 µm Day/Night Band, 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images

Suomi NPP VIIRS 0.7 µm Day/Night Band, 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images

There was an explosive eruption of the Villarrica volcano in central Chile on the morning of 03 March 2015; the Buenos Aires VAAC issued their first volcanic ash advisory based upon initial detection on 06:38 UTC GOES-13 imagery, although media report and blog sources indicated that the eruption started closer to 06:00 UTC (3 am local time). A comparison of 06:07 UTC Suomi NPP VIIRS 0.7 µm Day/Night Band (DNB), 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images (above; courtesy of William Straka, SSEC) revealed a bright glow on the DNB and near IR images, with a pronounced “hot spot” evident on the shortwave IR (yellow to orange pixels; the hottest shortwave IR brightness temperature was over 600 K!) and even the longwave IR (darker black pixels) images. The DNB image was particularly striking, with nearby clouds and surface features being illuminated by the eruption.

MODIS and GOES-13 multispectral false-color Red/Green/Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (below; click image to play animation) showed that there was detection of a thermal anomaly or “hot spot” (indicated by a red box) as early as 04:20 UTC (MODIS) and 05:45 UTC (GOES-13); the volcanic cloud filament — which was estimated to be at an altitude of 30,000 feet — could be seen drifting to the southeast following the eruption.

MODIS and GOES-13 false-color RGB images (click to play animation)

MODIS and GOES-13 false-color RGB images (click to play animation)

On GOES-13 10.7 µm IR channel images (below; click image to play animation), the volcanic cloud initially exhibited an IR brightness temperature as cold as -42ºC  (green color enhancement), but the cloud filament quickly became very diffuse and difficult to identify on the IR images by 09:38 UTC.

GOES-13 10.7 µm IR images (click to play animation)

GOES-13 10.7 µm IR images (click to play animation)

The 12 UTC rawinsonde profiles from Puerto Montt, Chile (station identifier SCTE) on 02 March and 03 March are shown below. On the 02 March profile, the -42º C temperature was at an altitude around 9400 meters or 30,800 feet; on the 03 March profile, -42º C was around 9100 meters or 29,900 feet.

Puerto Montt, Chile 12 UTC rawinsonde profiles on 02 March and 03 March

Puerto Montt, Chile 12 UTC rawinsonde profiles on 02 March and 03 March

On GOES-13 3.9 µm shortwave IR images (below; click image to play animation) a “hot spot” (black to yellow to red color enhancement) was seen for several hours after the initial eruption. The highest shortwave IR brightness temperature observed by GOES-13 was 340.8 K — much lower than than the >600 K observed with the higher spatial resolution Suomi NPP VIIRS instrument.

GOES-13 3.9 µm shortwave IR channel images (click to play animation)

GOES-13 3.9 µm shortwave IR channel images (click to play animation)

Improvements in Volcanic Ash detection with Himawari-8

January 25th, 2015
Himawari8_FalseColorVolcano_0230_25January

Himawari-8 False Color Imagery during an eruption of Klyuchevskoy Volcano, 0230 UTC 25 January 2015. Colors derived from bands as indicated (Click to enlarge)

Satellite data are used routinely to monitor Volcanoes for eruptions that can be potential aviation hazards. The Himawari-8 false-color image, above, derived from Himawari-8 AHI data, includes a volcanic plume that, even without the image annotation, is easy to detect. Consider the same scene, below, derived from MTSAT-2 imagery. The volcanic plume is far more difficult to discern. The superior spatial resolution on Himawari-8 IR channel data (2-km, vs 5-km on MTSAT) allows for better detection of this ash plume from Klyuchevskoy.

MTSAT2_FalseColorVolcano_0232_25January

MTSAT-2 False Color Imagery during an eruption of Klyuchevskoy Volcano, 0232 UTC 25 January 2015. Colors derived from bands as indicated (Click to enlarge)

Eruption of the Pavlof Volcano in Alaska

November 15th, 2014
Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

According to the Alaska Volcano Observatory, an eruption of the Pavlof Volcano began around 01:50 UTC on 13 November 2014. A comparison of nighttime images of Suomi NPP VIIRS 0.7 µm Day/Night Band (DNB) and 3.74 µm shortwave IR data at 13:07 UTC or 4:07 am local time on 14 November (above) showed the bright glow of the eruption on the DNB image, with the hottest pixel being 52º C (red color enhancement) on the shortwave IR image.

With the subsequent arrival of daylight, a break in the clouds allowed the faint volcanic plume to be observed on GOES-15 0.63 µm visible channel images (below; click image to play animation), drifting northwestward over the Bering Sea.

GOES-15 0.63 µm visible channel images (click to play animation)

GOES-15 0.63 µm visible channel images (click to play animation)

At 22:02 UTC on 14 November, the radiometrically-retrieved maximum volcanic ash mass loading value was 1.8 tons per km2, the maximum ash height was 16.8 km, and the maximum ash mass effective radius was 7.81 µm (below).

MODIS volcanic ash mass loading, ash height, and ash mass effective radius products

MODIS volcanic ash mass loading, ash height, and ash mass effective radius products

About an hour later, the volcanic ash plume could be seen on a 23:03 UTC Suomi NPP VIIRS Day/Night Band image, with a maximum 3.74 µm shortwave IR brightness temperature of 46º C at the summit of the volcano (below).

Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

The brown hue of the volcanic ash plume was very evident on Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images from the SSEC RealEarth web map server (below).

Suomi NPP VIIRS true-color RGB images

Suomi NPP VIIRS true-color RGB images

The intensity of the Pavlof eruption increased on 15 November, and a well-defined volcanic ash plume could be seen on GOES-15 0.63 µm visible channel images (below; click image to play animation). Pilot reports estimated that the top of the plume was as high as 38,000 feet.

GOES-15 0.63 µm visible channel images (click to play animation)

GOES-15 0.63 µm visible channel images (click to play animation)

On a comparison of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images at 22:45 UTC (below), the coldest cloud-top IR brightness temperature value was -55º C.

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

At 22:29 UTC, the CLAVR-x POES AVHRR Cloud Top Temperature product indicated a minimum value of -54º C, with a maximum Cloud Top Height value of 9 km; the -54º C cloud top temperature corresponded to an altitude of around 29,000 feet or 8.7 km on the 16 November/00 UTC Cold Bay AK rawinsonde profile.

POES AVHRR Cloud Top Temperature and Cloud Top Height products

POES AVHRR Cloud Top Temperature and Cloud Top Height products

A Suomi NPP VIIRS true-color RGB image at 23:04 UTC (below) suggested that the volcanic plume consisted of a dense layer of tan-colored ash, with a layer of mostly ice cloud at the top of the plume.

Suomi NPP VIIRS true-color RGB image

Suomi NPP VIIRS true-color RGB image