There are many GOES loops showing the moon’s shadow from the total solar eclipse on April 8, 2024 (UW/CIMSS; CIRA; Satellite Liaison; NOAA). Time compositing, in this case selecting the minimum brightness, shows the shadow from several times in a single frame.

Full Disk

The above image is a composite of 21 images, from 16:30 to 19:50 UTC (image start times). The composite consists of selecting the darkest pixel. Note that a special enhancement was applied to each image before the compositing. The dark regions from the Moon’s shadow are clearly evident. Note that less clouds are apparent in the composite, since the minimum values were chosen over time. Another Full Disk composite, but hourly, and of the CIMSS Natural color composite image.

CONUS + Meso-scale

A research request was submitted to satellite operators to have an ABI meso-scale sector “follow” the shadow, from Mexico to Canada. This special schedule was scanned. The time compositing procedure was applied to the 1-min meso-scale sectors, as well the 5-min CONUS sectors. This consisted of over 100 images, between 17:51 and 19:59 UTC. The dark regions from the Moon’s shadow is evident. A toggle (animated gif) between the composited image and the predicted path.

H/T

Thanks to those investigating / scheduling the meso’s on April 8th, including the NOAA NESDIS User Services team. Fun fact, this research request was initially submitted on May 3, 2023. Thanks also for the Eclipse Predictions by Fred Espenak, NASA’s GSFC. McIDAS-X was used for image generation. Thanks to the satellite operators, SDM, PRO, SAB and the NWS as well as UW/CIMSS (especially M. Gunshor and J. Nelson) and the SSEC Data Services. More on the ABI and the GOES-R series.

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The animation below from the CSPP Geosphere website (direct link to animation) shows regions of low clouds, some of which develop in the vertical, and some of which do not (see annotated image underneath the animation). Is there a product that can be used to discriminate between these two regions?

GOES-18 Total Precipitable Water fields, below, might help you understand why development occurs in some places (where there’s more moisture) and doesn’t occur in others (where there’s not quite so much moisture). In the color enhancement below, blue/green regions are relatively dry — 1.4 to 1.6 inches of TPW — and yellow and orange regions are not as dry: 1.8 to 2.0″ of TPW. Total Precipitable Water is a clear-sky product; high clouds that are masking the fields are generally moving south to north, and low clouds (including those that occasionally develop in the vertical) are moving towards the northwest. The low clouds are mostly static (as far as vertical growth is concerned) in regions that are diagnosed as dryer in the TPW fields.

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Use Level 2 Products from GOES-R to better understand and anticipate how the atmosphere will evolve in the near term.

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10-minute JMA Himawari-9 AHI Infrared Window (10.4 µm) images (above) showed an explosive eruption of Mount Ruang in Indonesia on 17 April 2024. Note that a thunderstorm was reported at Menado (station identifier WAMM) from 1400-1430 UTC, due to abundant lightning activity within the dense volcanic umbrella cloud.

In the Himawari-9 Infrared Window (10.4 µm) image at 1240 UTC (above), the coldest pixel exhibited a brightness temperature of -88.8ºC (dark purple enhancement) — with an adjacent warm pixel of -46.4ºC (green enhancement), possibly a result of compensating subsidence immediately downwind of the robust updraft (which penetrated the local tropopause and extended into the lower stratosphere).

Maximum radiometrically retrieved Ash Height values (source) reached 16-18 km. In a plot of rawinsonde data from Menado at 1200 UTC (below), this height corresponded to the 80-110 hPa pressure level.

In Himawari-9 Ash RGB images created using Geo2Grid (below), shades of pink around the the umbrella cloud represented higher concentrations of volcanic ash, while shades of green to yellow represented increasing concentrations of volcanic SO2.

27 hour long SO2 RGB loop from Himawari-9 over the #Ruang volcano eruption. Yellow and red are indicative of upper level SO2 which has been dispersed since the large plume was emitted beginning around 11:00 UTC yesterday (04/17/2024). Made with McIDAS-V. pic.twitter.com/4bNtINlqMA

— Robert Carp (@rmcarp) April 18, 2024

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Clean” Infrared Window (10.3 µm) images with an overlay of the Total Precipitable Water derived product (in non-cloudy areas) (above) showed that an axis of moisture was initially in place across all the Samoan Islands — peak TPW values were in excess of 2.0 in (brighter shades of magenta). The axis of moisture began to diminish somewhat over American Samoa after 0600 UTC — but as another lobe of higher moisture approached from the east around 1300 UTC, scattered showers began developing in the vicinity of the Manu’a Islands and Tutuila.

Since there is no radar coverage across the islands, 1-minute GOES-18 imagery was requested to support the 124th annual Flag Day celebration in American Samoa (which included numerous VIP visitors from the US Department of Defense and Legislature, Hawai’i State Department and local government).

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