Eruption of the Kilauea volcano in Hawai’i

December 21st, 2020 |

GOES-17 Shortwave Infrared (3.9 µm) and "Clean" Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-17 (GOES-West) Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) displayed the thermal anomaly (cluster of hot pixels) and brief volcanic cloud resulting from an eruption of the Kilauea volcano on the Big Island of Hawai’i on 21 December 2020. The coldest cloud-top 10.35 µm infrared brightness temperature was -34.6ºC at 0840 UTC — which roughly corresponded to the 300 hPa or 9.6 km altitude according to 12 UTC rawinsonde data from nearby Hilo (plot | text). However, this volcanic cloud quickly dissipated in the very dry air aloft.

GOES-17 Near-infrared (1.61 µm and 2.24 µm) and Shortwave Infrared images (below) showed the variation in thermal signatures during the hours leading up to sunrise. The signature in Near-Infrared imagery was occasionally attenuated by the passage of trade wind cumulus clouds over the eruption site.

GOES-17 Near-infrared (1.61 µm and 2.24 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

GOES-17 Near-infrared (1.61 µm and 2.24 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

A comparison of Suomi NPP VIIRS Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm) and Day/Night Band (0.7 µm) images (below) provided a high spatial resolution view of the thermal and emitted light signatures of the ongoing eruption at 1221 UTC.

Suomi NPP VIIRS Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm) and Day/Night Band (0.7 µm) images (credit: William Straka, CIMSS) [click to enlarge]

A larger-scale view of GOES-17 Shortwave Infrared, SO2 RGB and Ash RGB images (below) showed the southward transport of a mid/high-altitude plume of SO2 (lighter shades of yellow to cyan) from the initial eruption, followed by the southwestward transport of a more persistent low-altitude plume of SO2 as the eruption continued during the day. No signature of volcanic ash was indicated (either qualitatively on the Ash RGB images, or on retrieved ash products from this site). At times the thermal anomaly of the eruption site exhibited 3.9 µm infrared brightness temperatures as hot as 105ºC.

GOES-17 Shortwave Infrared (3.9 µm), SO2 RGB and Ash RGB images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm), SO2 RGB and Ash RGB images [click to play animation | MP4]

GOES-17 True Color RGB images created using Geo2Grid (below) displayed the volcanic fog (or “vog”) plume that moved southwestward during the day — a portion of which became entrained into the circulation of a lee-side cyclonic gyre southwest of the Big Island.

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

Eruption of the Lewotolok volcano in Indonesia

November 29th, 2020 |

Himawari-8 True Color RGB images [click to play animation | MP4]

Himawari-8 True Color RGB images [click to play animation | MP4]

JMA Himawari-8 True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) showed the volcanic clouds produced by an eruption of Lewotolok in Indonesia on 29 November 2020 — with one cloud plume moving to the northwest, and another moving more rapidly southeastward. This difference in volcanic cloud propagation was due to directional wind shear, as revealed by rawinsonde data from Kupang on the island of Timor (below), located about 250 km southeast of Lewotolok. A shift to northwesterly winds occurred at an altitude around 9 km (the 322 hPa pressure level).

Plot of rawinsonde data from Kupang, Indonesia [click to enlarge]

Plot of rawinsonde data from Kupang, Indonesia [click to enlarge]

Himawari-8 Ash RGB images [click to play animation | MP4]

Himawari-8 Ash RGB images [click to play animation | MP4]

Himawari-8 Ash RGB images (above) displayed an ash signature for both volcanic plumes, which became more diffuse after about 5 hours. Himawari-8 retrievals of Ash Height from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) showed maximum values in the 16-18 km range for the southeast-moving cloud (the  advisory issued by the Darwin VAAC listed maximum height values of 50,000 feet or 15 km).

Himawari-8 Ash Height [click to play animation | MP4]

Himawari-8 Ash Height [click to play animation | MP4]

Himawari-8 False Color images (below) indicated the presence of both SO2 (shades of yellow to green) and ash in the southeastward-moving volcanic cloud.

Himawari-8 False Color images [click to play animation | MP4]

Himawari-8 False Color images [click to play animation | MP4]


Mount Sinabung eruption in Indonesia

August 10th, 2020 |

Himawari-8 True Color RGB images [click to play animation | MP4]

Himawari-8 True Color RGB images [click to play animation | MP4]

JMA Himawari-8 True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) displayed the gray to tan hues of a narrow west-to-east oriented volcanic ash cloud following an eruption of Mount Sinabung on 10 August 2020.

A sequence of Terra MODIS False Color RGB, Ash Probability, Ash Loading, Ash Height and Ash Effective Radius products from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) showed various characteristics of the ash plume at 0415 UTC.

Terra MODIS False Color RGB, Ash Probability, Ash Loading, Ash Height and Ash Effective Radius [click to enlarge]

Terra MODIS False Color RGB, Ash Probability, Ash Loading, Ash Height and Ash Effective Radius [click to enlarge]

A plot of 00 UTC rawinsonde data from Medan (below) helped to explain the different ash height and ash transport characteristics — the higher-altitude portion of the ash plume was transported westward by easterly flow above the 500 hPa (5.9 km) level, while the lower-altitude portion moved eastward due to westerly winds below 500 hPa.

Plot of 00 UTC rawinsonde data from Medan, Indonesia [click to enlarge]

Plot of 00 UTC rawinsonde data from Medan, Indonesia [click to enlarge]

1 week of volcanic cloud emission from Nishioshima

August 1st, 2020 |

Himawari-8 Ash RGB images, from 25 July to 01 August 2020 [click to play animation | MP4]

Himawari-8 Ash RGB images, from 25 July to 01 August 2020 [click to play animation | MP4]

JMA Himawari-8 Ash Red-Green-Blue (RGB) images created using Geo2Grid (above) displayed the nearly continuous volcanic cloud emanating from Nishinoshima during the 1-week 25 July to 01 August period (faster animations are also available: gif | mp4). Brighter shades of pink in the Ash RGB images suggest a higher concentration of ash within the volcanic cloud. The direction of plume transport switched from northwesterly/westerly to southerly/southeasterly during this time, which is explained by the transition in wind direction within much of the troposphere as revealed by rawinsonde data from nearby Chichijima (below).

Plots of rawinsonde data from Chichijima [click to enlarge]

Plots of rawinsonde data from Chichijima [click to enlarge]

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]

After the transition to southerly transport, VIIRS True Color RGB images from NOAA-20 and Suomi NPP as visualized using RealEarth (above), the surface visibility at Iwo Jima RJAW dropped to 4 miles on 01 August (below) as the hazy volcanic plume drifted across the area.

Time series plot of surface observation data from Iwo Jima [click to enlarge]

Time series plot of surface observation data from Iwo Jima [click to enlarge]