Multiple pyrocumulonimbus clouds produced by a bushfire in s…
Himawari-9 – CIMSS Satellite Blog (Scott Bachmeier)
10-minute Himawari-9 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.4 µm, bottom) images, from 0250-0830 UTC on 13 December [click to play animated GIF | MP4]
10-minute Full Disk scan JMA Himawari-9 AHI Visible, Shortwave Infrared and Infrared Window images (above) showed multiple pulses of pyrocumulonimbus (pyroCb) clouds that were spawned by a large bushfire in southwest Queensland, Australia on 13 December 2025. The pyroCb cloud pulses exhibited a cloud-top 10.4 µm infrared brightness temperature (IRBT) of -40ºC (denoted by darker blue pixels) or colder — a necessary condition to be classified as a pyroCb, since that temperature assured that heterogeneous glaciation had occurred at the cloud top — with some IRBTs of the larger pyroCb clouds in the -65 to -69ºC range (darker shades of green). In addition, note that the pyroCb cloud tops appeared as darker shades of gray in the Shortwave Infrared images, due to enhanced solar reflection off the smaller smoky ice crystals.
Himawari-9 Fire Temperature RGB + Infrared Window images viewed using RealEarth (below) indicated that the large bushfire was burning just south of Durham, Queensland.
10-minute Himawari-9 Fire Temperature RGB + Infrared Window (10.4 µm) images, from 0230-0900 UTC on 13 December [click to play MP4 animation]
According to a plot of rawinsonde data from Charlesville, Queensland at 2300 UTC on 12 December (below) — about 4 hours prior to the initial pyroCb pulse — the coldest pyroCb cloud-top IRBTs in the -65 to -69ºC range were near or just above the Most Unstable (MU) air parcel’s Equilibrium Level (EL), and just above the local tropopause.
Plot of rawinsonde data from Charleville, Queensland at 2300 UTC on 12 December [click to enlarge]
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