CSPP GeoSphere views of the Soufriere Eruption on 11 April 2021

April 11th, 2021 |

GOES-16 True Color Imagery, 1210-1600 UTC on 11 April 2021 (click to animate)

CSPP GeoSphere allows a user to view True Color imagery (and individual GOES-16 bands) in real time using data from the four GOES-16 domains:  Full Disk, CONUS, and Mesoscale Sectors 1 and 2.  The animation above shows the 1330 UTC eruption (11 April 2021) of Soufriere, one of a series of eruptions from that volcano (as discussed here and elsewhere).  The ash emitted by the short (duration) eruption then moves westward towards Barbados, following upper-level winds.  (Low-level winds are easterly).  The rapid ascent of the ash cloud is documented below, showing 4 images from the Full Disk imagery at 1320, 1330, 1340 and 1350 UTC.

GOES-16 True Color Imagery, at 1320, 1330, 1340 and 1350 UTC on 11 April 2021 (click to animate)

Rapid changes suggest Mesoscale imagery would be useful.  Indeed, volcanic events area ranked #2 on the GOES-R MDS Priority List, after only a SPC High/Moderate Risk for Severe weather.  Thus, mesoscale Sector 2 imagery was available over the area.   That is shown below and it better captures the time of the eruption and better resolves the ascent through the troposphere.

GOES-16 Mesoscale sector 2 True Color Imagery, 1320-1347 UTC (Click to animate)

Seven consecutive zoomed-in 1-minute images are shown below, from 1329 through 1336 UTC on 11 April (with the map removed; CSPPGeo link used here; a similar animation from the CIRA Slider is here.) They show the initial stages of this particular eruption.  A Pileus cap is obvious at the top of the eruption at 1329 UTC. (Animation available here as an mp4).

GOES-16 Mesoscale sector 2 True Color Imagery, 1329-1336 UTC (Click to enlarge)

Quantitative information on some aspects of this series of events can be found at the VOLCAT website.  You can also find information at the Washington DC VAAC (Volcanic Ash Advisory Center).

Multi-day eruptions of the La Soufrière volcano in the West Indies

April 9th, 2021 |

GOES-16 Ash RGB images [click to play animation | MP4]

GOES-16 Ash RGB and SO2 RGB images [click to play animation | MP4]

GOES-16 (GOES-East) Ash RGB and SO2 RGB images (above) displayed signatures of two distinct eruptions of the La Soufrière volcano on the island of Saint Vincent in the West Indies on 09 April 2021. Signatures of high ash or SO2 concentrations appear as brighter shades of pink on the RGB images. Significant ash fall on parts of the island forced evacuations of some communities. The SO2 signature for the second eruption was much more pronounced and widespread.

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below) showed that coldest cloud-top infrared brightness temperatures associated with the first eruption (which began shortly before 1250 UTC) were -62ºC, while the second and more explosive eruption (which began shortly after 1900 UTC) exhibited temperatures as cold as -78ºC.

GOES-16 "Clean" Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 True Color RGB images created using Geo2Grid (below) showed the characteristic tan-colored hues of a volcanic cloud having significant ash loading.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images (credit: Tm Schmit, NOAA/NESDIS/ASPT) [click to play animation | MP4]

A number of quantitative radiometrically-retrieved products are available from the NOAA/CIMSS Volcanic Cloud Monitoring site — some of which include Ash Height, Ash Probability, Ash Loading and Ash Effective Radius (below).

Ash Height product [click to play animation | MP4]

Ash Height product [click to play animation | MP4]

Ash Probability product [click to play animation | MP4]

Ash Probability product [click to play animation | MP4]

Ash Loading product [click to play animation | MP4]

Ash Loading product [click to play animation | MP4]

Ash Effective Radius product [click to play animation | MP4]

Ash Effective Radius product [click to play animation | MP4]

===== 10 April Update =====

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) displayed the volcanic cloud associated with numerous explosive eruptions that continued during much of the day on 10 April. The coldest cloud-top infrared brightness temperature of -84.8ºC occurred at 1058 UTC (and would have been missed by the routine 10-minute images over that area). This cold overshooting top infrared brightness temperature roughly corresponded to an altitude of 18.2 km, or 1.8 km above the tropopause according to 12 UTC rawinsonde data from Barbados (below).

Plot of 12 UTC rawinsonde data from Grantley Adams, Barbados [click to enlarge]

Plot of 12 UTC rawinsonde data from Grantley Adams, Barbados [click to enlarge]

GOES-16 True Color RGB images within +/- 30 minutes of the -84.8ºC infrared brightness temperature are shown below — an abrupt penetration of the existing volcanic cloud top was seen by the newly-developed overshooting top.

GOES-16 True Color RGB images [click to play animation MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 Ash RGB images (below) indicated high concentrations of volcanic ash (brighter shades of pink) spreading out slowly around the island of Saint Vincent at lower altitudes, and being transported rapidly eastward at higher altitudes. To the north, light ash fall was limiting the surface visibility to 2-3/4 miles at Saint Lucia (TLPL) — while farther to the east heavier ash fall on the island of Barbados visibility was occasionally being restricted to around 1/2 mile (1000 meters) at Grantley Adams Airport (TBPB).

GOES-16 Ash RGB images [click to play animation | MP4]

GOES-16 Ash RGB images [click to play animation | MP4]

GOES-16 SO2 RGB images (below) showed that high concentrations of SO2 (shades of red to orange) were also being emitted during the series of eruptions.

GOES-16 SO2 RGB images [click to play animation | MP4]

GOES-16 SO2 RGB images [click to play animation | MP4]

GOES-17 (GOES-West) provided an oblique view of these volcanic clouds, which were very near the extreme limb of the satellite view — a comparison of GOES-17 and GOES-16 Full Disk sector “Red” Visible (0.64 µm) images for one of the more explosive events on 10 April is shown below. The magnification factor is identical in both sets of GOES images, though they are displayed in the native projection of each satellite. A similar comparison of 10-minute Full Disk sector GOES-17 and 1-minute Mesoscale sector GOES-16 Visible images is available here.

“Red” Visible (0.64 µm) images from GOES-17 (left) and GOES-16 (right) [click to play animation | MP4]

A toggle between True Color RGB images from GOES-16 and GOES-17 at 1930 UTC (below) further illustrates the parallax displacement associated with the large viewing angle from GOES-17.

True Color RGB images from GOES-16 and GOES-17, at 1930 UTC (credit: Tim Schmit, NOAA/NESDIS/ASPB) [click to enlarge]

True Color RGB images from GOES-16 and GOES-17, at 1930 UTC (credit: Tim Schmit, NOAA/NESDIS/ASPB) [click to enlarge]

===== 11 April Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) image (credit: William Straka, CIMSS) [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) image (credit: William Straka, CIMSS) [click to enlarge]

A nighttime NOAA-20 VIIRS Day/Night Band (0.7 µm) image (above) revealed mesospheric airglow waves propagating northeastward and eastward away from the volcano, which was still actively erupting every few hours.

The periodic violent eruptions continued into the daytime hours on 11 April — and GOES-16 Mid-level Water Vapor (6.9 µm) images (below) showed shock waves emanating radially outward from the initial volcanic cloud location following each eruption.

GOES-16 Mid-level (6.9 µm) Water Vapor images [click to play animation | MP4]

GOES-16 Mid-level (6.9 µm) Water Vapor images [click to play animation | MP4]

===== 13 April Update =====

GOES-16 "Clean" Infrared Window (10.35 µm) and Ash RGB images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) and Ash RGB images [click to play animation | MP4]

Eruptions continued on the morning of 13 April, as seen in GOES-16 Infrared and Ash RGB images (above).

A 4-day animation of GOES-16 Ash RGB images — covering the period from 1230 UTC on 09 April to 1230 UTC on 13 April — is shown below.

GOES-16 Ash RGB images, 09-13 April [click to play MP4 animation]

GOES-16 Ash RGB images, 09-13 April (credit Tim Schmit, NOAA/NESDIS/ASPB) [click to play MP4 animation]

Eruption of Mount Etna

March 24th, 2021 |

Meteosat-11 Ash Height images [click to play animation | MP4]

Meteosat-11 Ash Height images [click to play animation | MP4]

EUMETSAT Meteosat-11 Ash Height retrievals from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed that an eruption of Mount Etna in Sicily, Italy on 24 March 2021 produced an ash cloud which rose to heights of 7-8 km (darker shade of green).

The corresponding Meteosat-11 Ash Loading images are shown below — ash loading appeared to be light to moderate within much of the volcanic cloud.

Meteosat-11 Ash Loading images [click to play animation | MP4]

Meteosat-11 Ash Loading images [click to play animation | MP4]

Ash Loading values retrieved using Suomi NPP VIIRS data at at 1200 UTC (below) were notably higher than those from Meteosat-11, given the higher spatial resolution and additional spectral band data available from the VIIRS instrument.

Suomi NPP VIIRS Ash Loading at 1200 UTC [click to enlarge]

Suomi NPP VIIRS Ash Loading at 1200 UTC [click to enlarge]

A toggle between VIIRS True Color RGB images from NOAA-20 and Suomi NPP as viewed using RealEarth (below) revealed hues of tan to light brown within the volcanic plume, further supporting the presence of an elevated ash content.

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

Eruption of Mount Etna

February 19th, 2021 |

Meteosat-11 False Color RGB images [click to play animation | MP4]

Meteosat-11 False Color RGB images [click to play animation | MP4]

EUMETSAT Meteosat-11 False Color RGB images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed the signature of a volcanic cloud associated with an eruption of Mount Etna on 19 February 2021. The brighter shades of red/magenta suggested the presence of ash within the volcanic cloud. This was supported by high values of retrieved Ash Loading (below).

Meteosat-11 Ash Loading product [click to play animation | MP4]

Meteosat-11 Ash Loading product [click to play animation | MP4]

A Meteosat-11 Ash Effective Radius Product (below) depicted rather large ash particles, generally in the 14-16 µm range.

Meteosat-11 Ash Effective Radius product [click to play animation | MP4]

Meteosat-11 Ash Effective Radius product [click to play animation | MP4]

A Meteosat-11 Ash Height product (below) showed retrieved values up to 12-13 km (magenta enhancement) for parts of the volcanic cloud.

Meteosat-11 Ash Height product [click to play animation | MP4]

Meteosat-11 Ash Height product [click to play animation | MP4]

Another version of Meteosat-11 False Color RGB images which use 8.7 µm data (below) revealed shades of green that indicated a higher concentration of SO2 within the southern portion of the volcanic cloud.

Meteosat-11 False Color RGB images [click to play animation | MP4]

Meteosat-11 False Color RGB images [click to play animation | MP4]