Eruption of Bogoslof in Alaska’s Aleutian Islands

May 28th, 2017 |

Himawari-8 Visible (0.64 µm, left) and Infrared Window (10.4 µm, right) images, with hourly surface and ship reports plotted in yellow [click to play animation]

Himawari-8 Visible (0.64 µm, left) and Infrared Window (10.4 µm, right) images, with hourly surface and ship reports plotted in yellow [click to play animation]

The Bogoslof volcano in Alaska’s Aleutian Islands erupted around 2216 UTC on 29 May 2017. A comparison of Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images (above; MP4) showed the volcanic cloud as it drifted north/northeastward.

A very oblique view of the volcanic cloud was captured by Korean COMS-1 satellite at 2315 UTC (below).

COMS-1 Visible (0.67 µm) images, with surface observations plotted in yellow [click to enlarge]

COMS-1 Visible (0.67 µm) images, with surface observations plotted in yellow [click to enlarge]

Himawaari-8 false-color images from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) revealed the initial signature of a volcanic cloud — however, this signature became less distinct after about 02 UTC on 29 May.

Himawari-8 false-color RGB images [click to play animation]

Himawari-8 false-color RGB images [click to play animation]

A different type of Himawari-8 false-color imagery (below) makes use of the 8.5 µm spectral band, which can help to infer the presence of sulfur dioxide within a volcanic cloud feature. A similar 8.4 µm band is available from the ABI instrument on the GOES-R series of satellites.

Himawari-8 false-color images [click to play animation]

3Himawari-8 false-color images [click to play animation]

A blend of Himawari-8 Infrared Window (10.4 µm) and radiometrically-retrieved Ash Cloud Height is shown below; the maximum ash cloud height was generally in the 10-12 km (33,000-39,000 feet above sea level) range (dark blue color enhancement). A volcanic ash signal was no longer apparent after 2320 UTC — this was likely due to enhanced ash particle removal via water (both liquid and ice) related processes.

Himawari-8 Infrared Window (10.4 µm) images and Ash Cloud Height retrievals [click to play animation]

Himawari-8 Infrared Window (10.4 µm) images and Ash Cloud Height retrievals [click to play animation]

A DigitalGlobe WorldView image at 2234 UTC (below) provided remarkable detail of the Bogoslof volcanic cloud shortly after the eruption began.


Cyclone Donna in the South Pacific Ocean

May 7th, 2017 |

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Cyclone Donna (18P) formed in the South Pacific Ocean (northeast of Vanuatu) on 02 May 2017. Himawari-8 Infrared Window (10.4 µm) images during the 03-06 May period (above) revealed the formation of multiple convective bursts, many exhibiting cloud-top IR brightness temperatures of -90º C and colder.

On 07 May, Cyclone Donna rapidly intensified from a Category 2 to a Category 4 storm (SATCON | ADT) — and Himawari-8 Infrared Window images (below) showed the presence of a large eye for a few hours. Environmental factors favoring rapid intensification included warm sea surface temperatures and light vertical wind shear.

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

A comparison of GMI Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images from the CIMSS Tropical Cyclones site (below) showed that the actual diameter of the eye was much larger on microwave imagery around 1400 UTC on 07 May.

GMI Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images [click to enlarge]

GMI Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images [click to enlarge]

Aeroflot 270 encounters severe turbulence approaching Thailand

May 1st, 2017 |

Himawari-8 Water Vapor (6.9 µm) images, with plots of turbulence intensity along the flight path [click to enlarge]

Himawari-8 Water Vapor (6.9 µm) images, with plots of turbulence intensity along the flight path [click to enlarge]

Aeroflot Flight 270 encountered severe turbulence just off the coast of Myanmar (CNN | Aviation Herald) as it was flying toward its destination of Bangkok, Thailand on 01 May 2017. According to information from FlightRadar24 (flight map) and FlightAware (flight map | flight log) the time and location of the turbulence was around 23:54-23:56 UTC, near 16.4 N latitude, 97.4 East longitude, at the cruising altitude of 35,000 feet. Himawari-8 Water Vapor (6.9m) images (above; courtesy of Sarah Griffin, CIMSS) indicated that the aircraft made a slight course correction to fly over or through a small cluster of rapidly-developing thunderstorms — this convection was the likely cause of the turbulence.

Closer views of Himawari-8 Visible (0.64 µm), Water Vapor (6.9 µm) and Infrared Window (10.4 µm) images, centered at the location of the turbulence encounter (below), showed the rapid development of individual convective elements within this cluster of thunderstorms. Cloud-top infrared brightness temperatures were around -70º C on the 01 May / 00:10 UTC image.

Himawari-8 Visible (0.64 µm, top), Water Vapor (6.9 µm, middle) and Infrared Window (10.4 µm, bottom) images [click to enlarge]

Himawari-8 Visible (0.64 µm, top), Water Vapor (6.9 µm, middle) and Infrared Window (10.4 µm, bottom) images [click to enlarge]

Cyclone Debbie makes landfall in Queensland, Australia

March 28th, 2017 |

Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images [click to play animation]

Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images [click to play animation]

Cyclone Debbie formed in the Coral Sea on 22 March 2017, and eventually intensified to a Category 3 storm (ADT | SATCON) as it moved southward toward Australia. Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images (above) showed the eye of Debbie as it was making landfall in Queensland, near Prosperpine (YBPN).

Landsat-8 false-color, with Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images [click to enlarge]

Landsat-8 false-color, with Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images [click to enlarge]

The Landsat-8 satellite made an overpass of the eye at 2358 UTC (above), as a large convective burst had developed within the northern semicircle of the eyewall (which was also evident in the corresponding Himawari-8 Visible and Infrared Window images viewed using RealEarth).

Himawari-8 Infrared Window (10.4 µm) and GMI Microwave (85 GHZ) Images around 1430 UTC on 27 March [click to enlarge]

Himawari-8 Infrared Window (10.4 µm) and GMI Microwave (85 GHZ) Images around 1430 UTC on 27 March [click to enlarge]

Debbie was undergoing an eyewall replacement cycle as the storm center approached the coast — this was evident in Microwave (85 GHz) images from GMI at 1425 (above) and SSMIS at 2017 UTC (below) from the CIMSS Tropical Cyclones site.

Himawari-8 Infrared Window (10.4 µm) and DMSP-18 SSMIS Microwave (85 GHz) images around 2017 UTC on 27 March [click to enlarge]

Himawari-8 Infrared Window (10.4 µm) and DMSP-18 SSMIS Microwave (85 GHz) images around 2017 UTC on 27 March [click to enlarge]

The MIMIC Total Precipitable Water product (below; also available as an MP4 animation) showed copious tropical moisture associated with Cyclone Debbie, which led to rainfall accumulations as high as 780 mm (30.7 inches) — with rainfall rates up to 200 mm (7.9 inches) per hour — and record flooding along the coast from Brisbane to Lismore.

MIMIC Total Precipitable Water product [click to play animation]

MIMIC Total Precipitable Water product [click to play animation]