One of the gases emitted from the Mauna Loa eruption is SO₂. The 0223 UTC 30 November update from this site notes that emission rates of approximately 250,000 tonnes [sic] per day were measured on 28 November! What satellite products can be used to diagnose this gas qualitatively and quantitatively? There is an SO₂ RGB created with GOES-R channels, so GOES-17 and GOES-18 are available to monitor SO₂ qualitatively. The animation above shows both the SO₂ and Ash RGBs over Hawaii, at half-hourly intervals. The light green regions around and downstream of Mauna Loa highlight parts of the lower troposphere that are rich in SO₂. (Here is the SO₂ RGB Quick Guide).

Longer animations using 5-minute images of GOES-17 Ash RGB and SO2 RGB imagery — from 1801 UTC on 29 November to 1501 UTC on 30 November — are shown below.

Gridded NUCAPS fields available at this site from SPoRT include SO2 concentrations, as shown above. A minor increase in SO2 concentration is indicated. However, the Quality indicators suggest that the NUCAPS retrievals over part of Hawai’i failed.

NASA has a global SO₂ monitoring site here that shows daily qualitative imagery from OMI (on board Aura), OMPS (on board Suomi-NPP) and Tropomi. OMI imagery is here, OMPS imagery is here, and TROPOMI imagery is here. (Note that the TROPOMI imagery is not processed as quickly as OMI and OMPS imagery). The OMPS images for 28 and 29 November, shown below, show values off the scale.

SO₂ concentrations/distributions from OMI on Aura and OMPS on Suomi NPP are also available at NASA Worldview as shown below. OMPS imagery is available more quickly at NASA Worldview.

The toggle below compares OMI (Aura) and OMPS (NPP) estimates of SO₂ concentration on 28 November. Aura and NPP have similar orbits so there is little time difference between the two observations. Both show values greater than 32 DU.

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The JStar Mapper also shows SO2 concentration (from Suomi NPP OMPS) on top of Suomi NPP VIIRS True-Color imagery, as shown below.

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Mauna Loa on the Big Island of Hawai’i became active overnight, ending a quiescent phase that started back in 1984 — the longest period of dormancy for this Volcano since the 1800s. The Ash Probability animation above, combining both GOES-17 PACUS and GOES-17 Full Disk imagery (using imagery from this site) shows the Ash Cloud from this eruption moving northeastward from Hawai’i into the Pacific Ocean. The hot spot of the caldera is also apparent in the imagery.

The SSEC/CIMSS Volcano Monitoring website also includes a Thermal Monitoring tab, and the information for Mauna Loa (link) from 0926 to 1526 UTC on 28 November is shown below.

Tim Schmit (NOAA STAR/ASPB) created the 16-panel animations below, one showing all GOES-17 channels and one showing all GOES-18 channels. The heat signature is very apparent at 3.9 µm — but there is also a significant contributions at 1.6 µm and 2.2 µm! The window channels (Bands 11, 13, 14 and 15 at 8.4 µm, 10.3 µm, 11.2 µm and 12.3 µm) also show the heat signature. The effects of the Loop Heat Pipe malfunction on GOES-17 are also apparent in the Band 12 and Band 16 imagery (9.6 µm and 13.3 µm) by the end of the animation; GOES-18 has a more pristine look. Post-launch check-outs for GOES-18 continue, and it is scheduled to become operational as GOES-West in January of 2023. (GOES-18 data in the animation are preliminary and non-operational).

The animation below shows the Clean Window Infrared (10.3 µm) and the Fire Temperature RGB. Note the ash cloud in the 10.3 µm imagery is difficult to distinguish from other clouds, except by inferring a connection to the sudden hot spot in the Fire Temperature RGB. Channel difference products, however, such as the Split Cloud Top Phase (11.2 µm – 8.4 µm), shown underneath the animation below, do highlight the ash cloud (compare the signals in the Ash Cloud stretching east-northeast of Hawai’i with the cloud approaching Hawai’i from the southwest), as would RGBs that incorporate that difference field (that is, the Ash RGB, a variation of which is available at the SSEC/CIMSS volcano website, from both ABI and VIIRS data).

Larger-scale animations of GOES-17 Ash RGB and SO2 RGB images (below) exhibited a strong signature of SO2 within the volcanic cloud — particularly the segment that drifted east-northeastward away from the Big Island of Hawai`i during the 0931-2101 UTC period.

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NOAA-20 overflew Hawai’i shortly after 1130 UTC, and the higher-resolution (compared to ABI) VIIRS instrument gave a good view of the eruption. The I04 (3.74 µm) channel showed such warm temperatures that wrap-around effect occurred in the imagery (the white region that is within the orange/red center of the signal), and the visible signal was so bright that a hysteresis effect is apparent downscan of the volcano in the Day Night band imagery. Note in the Day Night Band image that a very small signal is apparent over Kilauea to the southeast of Mauna Loa.

For more information on this evolving event, refer to this USGS website, or this one. The CIMSS Volcanic Monitoring website includes satellite imagery and interpretation of this event. Also, as of 1900 UTC on 28 November 2022, GOES-17 Mesosector 1 is positioned over Hawai’i to give 1-minute imagery over the volcano. (SSEC Geo Browser link ; CIRA Slider ; NOAA Star Website ; Wisconsin AOS site ; College of Dupage)

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GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the circulation associated with an anomalously-deep middle tropospheric cutoff low as it moved from northern Mexico across Texas during the 1301 UTC on 25 November to 2101 UTC on 26 November 2022 time period. Elevated convective elements rotating within the cutoff low helped to enhance precipitation rates in portions of western Texas and eastern New Mexico — with accumulating snowfall occurring at many locations.

As the system moved off to the east during the day on 26 November, GOES-16 “Red” Visible (0.64 µm) and Day Snow-Fog RGB images (below) revealed the extent of snow cover (darker shades of red in the RGB imagery) across parts of southeastern New Mexico and southwestern Texas.

In a toggle between GOES-16 Day Snow-Fog RGB and Land Surface Temperature (LST) derived product images at 2101 UTC (below), LST values over the deepest snow cover just west of the New Mexico / Texas border were as cold as the mid 30s F (compared to 50s and 60s F over bare ground just to the east and west of that snow cover). 12 UTC snow depth reports within that patch of snow cover were 4-5 inches.

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The Ahyi Seamount is an underwater volcano in the northern Marianas that rises to within 137 m of the Pacific Ocean surface (Click here for more information). VIIRS True-color imagery within the past week shows discoloration in the ocean over the seamount location, suggestive of some sort of eruptive activity. (See this News Article). The image above using Suomi NPP VIIRS data, (annotated images courtesy Meteorologist Nick Slaughter at the National Weather Service office on Guam), shows slight discoloration in the box centered on the seamount location. The NOAA-20 true-color image below, shows the evolution of the discoloration in the 45 minutes between images.

A second Suomi NPP Pass also viewed the scene at 0408 UTC on 25 November 2022 (NPP Orbits for the 25th can be viewed here; the NOAA-20 orbits are here). The movement of the discoloration, as noted by the annotations, differs from the atmospheric flow.

Suomi NPP and NOAA-20 data over Guam are provided by a Direct Broadcast antenna attached to the office. Data are processed for AWIPS using CSPP, the Community Satellite Processing Package, and Polar2Grid.

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Careful inspection of Suomi NPP True-Color imagery at the JStar Mapper reveals faint discoloration over the seamount on 23 November as well, as shown below.

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Many Thanks to Nick Slaughter, WFO GUM, for both the imagery and the information on this event!

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