JMA Himawari-9 Infrared Window (10.4 µm) images, from 1810 UTC on 29 April to 0010 UTC on 30 April [click to play animated GIF | MP4]

12 days after its powerful eruption on 17 April, 10-minute JMA Himawari-9 AHI Infrared Window (10.4 µm) images (above) showed another explosive eruption of Mount Ruang in Indonesia on 29 April 2024. The coldest cloud-top infrared brightness temperatures reached -90ºC (internal yellow pixels) at 1850 UTC, shortly after the eruption onset. The volcanic umbrella cloud exhibited concentric cloud-top gravity waves. At the surface, volcanic ash (VA) was reported at Menado (station identifier WAMM: text | plot) beginning at 0000 UTC on 30 April, which restricted the visibility to 3-4 miles.

The cloud-top gravity waves were more apparent in higher-resolution Himawari-9 Red Visible (0.64 µm) images (below).

JMA Himawari-9 Red Visible (0.64 µm) images, from 2140-2240 UTC on 29 April [click to play animated GIF | MP4]

A toggle between Himawari-9 Visible and Infrared images at 2150 UTC on 29 April (below) showed that the primary volcanic plume (which reached heights above the broader umbrella cloud) exhibited warmer infrared brightness temperatures — indicating that it had penetrated the local tropopause and extended into the lower stratosphere.

JMA Himawari-9 Red Visible (0.64 µm) and Infrared Window (10.4 µm) images at 2150 UTC on 29 April [click to enlarge]

A plot of rawinsonde data from Menado, Indonesia at 0000 UTC on 30 April is shown below.

Plot of rawinsonde data from Menado, Indonesia at 0000 UTC on 30 April [click to enlarge]

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