The TROPICS constellation of satellites was augmented by a final launch of two cubesats from the Mahia Rocket Launch site at the south end of the Mahia Peninsula on the east coast of New Zealand’s North Island on 26 May 2023. GOES-18 visible imagery, above, stepping from 0320 to 0350 UTC on 26 March, shows a smudge in the 0340 UTC imagery (highlighted below). What facts argue for this feature being associated with the launch? The smudge is there at the correct time: launch was at 1046 PM CDT or 0346 UTC on 26 May. The timestamp of the image, 0340 UTC, is when ABI starts scanning at the North Pole; the Mode 6 Scanning timeline (here) suggests scanning at 39^oS, the latitude of the Mahia Launch facility, occurred between 0347 and 0348 UTC. Thus, the plume would be at considerable height in the image. The cubesats do travel west to east (see the figure at this page) so you should not expect the plume to be west of the launch site. However, Mahia, at 39.3° S, 177.9° E is far from the GOES-18 sub-satellite point (0^oN, 137^o W), so the westward displacement of the (possible) plume is likely an artifact of parallax (link) which for that location and a 50000′ height is close to 40km/25 miles southwestward of its true location.

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Note: the reflectance range for GOES-18 visible imagery above has been altered for this post, from the default (0-130) to 1-20 to better highlight the possible plume.

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GOES-16 (GOES-East) Ash RGB images and Dust RGB images (above) showed numerous volcanic plumes emanating from Popocatépetl in central Mexico during the 5-day period from 21 May – 25 May 2023. On 21 May, the airport at Puebla (MMPB) was temporarily closed, due to the potential adverse impact of volcanic ash to aviation (1731 UTC images) — and ash fall occurred within the city. At times the volcanic plumes were either partially or completely obscured by meteorological clouds, but for the most part the majority of eruptive events were well-sampled by the 5-minute GOES-16 imagery.

Even though the Ash RGB and Dust RGB products leverage the same ABI spectral bands, the various RGB components are scaled differently — which in this case led to the ash plumes exhibiting a more notable signature in the Dust RGB images (brighter shades of pink to magenta).

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Direct Broadcast data from the antenna on Guam (processed with CSPP data) at 1558 UTC on 25 May show the structure of a very strong typhoon. Mawar at 1800 UTC was a Super Typhoon with sustained winds of 155 knots. (Blog Post). The toggle above shows I05 (11.45 µm) and Day Night Band visible (0.70 µm) imagery. There are (again) indications of mesospheric gravity waves in the Day Night Band imagery (i.e., concentric light/dark bands surrounding the storm, especially west and north of the storm). The 11.45 infrared imagery shows a very warm eye. In both images, the symmetric nature of the storm is apparent, and strong convection in the outer bands.

At 1650 UTC, Suomi NPP provided I05 and Day Night Band data, shown below. The Mesospheric Gravity Waves are perhaps more noteable in the Suomi NPP Day Night imagery.

Thanks to Douglas Schumacher, SSEC/CIMSS, for the imagery!

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Target Sector (2.5-minute interval) JMA Himawari-9 Visible and Infrared images (above) covered the period +/- 2 hours when Super Typhoon Mawar reached Category 5 intensity at 0600 UTC on 25 May 2023. Mesovortices within the eye were evident in Visible imagery, with the eye exhibiting a “stadium effect” geometry (two signatures that are often associated with intense tropical cyclones).

A DMSP-17 SSMIS Microwave (85 GHz) image at 0911 UTC from the CIMSS Tropical Cyclones site (above) showed Mawar to the west of Guam, with a well-defined, completely closed eyewall along with a spiral band wrapping into the storm center from the south. Later in the day, Mawar further intensified to 155 knots at 1800 UTC (JTWC advisory | ADT | SATCON | D-MINT | D-PRINT) — and a DMSP-18 SSMIS Microwave image at 1905 UTC (below) revealed a distinct pair of spiral bands.

As also mentioned in this blog post, a Suomi-NPP VIIRS Day/Night Band (0.7 µm) image valid at 1655 UTC (below) revealed mesospheric airglow waves (reference) radiating hundreds of miles northward through westward away from Mawar — these vertically-propagating gravity waves were generated by deep convection within Mawar’s eyewall.

A long animation of Himawari-9 “Clean” Infrared Window (10.4 µm) images (below) showed that the eye of Mawar exhibited a small amount of trochoidal motion during the day.

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