SMS-2

The main Mount St. Helens eruption was May 18, 1980 — yet there were also later paroxysmal eruptions. Imagery from NASA’s SMS-2 (Synchronous Meteorological Satellite) monitored two more Mount St. Helens eruptions on June 12th (local time), 1980, as shown above. Note that in “UTC-time”, the eruption took place on June 13th. A similar side-by-side SMS-2 visible and infrared animation (without the arrows) is available here (in addition to one without the red location box).

A visible band animation without the red square at the location of Mount St. Helens is shown above. The second plume coated Portland (OR) with ash. For more on this case, see Wikipedia and the USGS. Here’s the same loop and image, but without the red location box.

The volcanic ash plume was also evident in the infrared window band, below, but the imagery has fairly coarse spatial (and temporal) resolution compared to today’s GOES-R series ABI (which allows much improved volcanic cloud monitoring). This longer IR loop shows the 2nd plume as well.

Swipe between SMS-2 Visible and Infrared bands. Red square notes Mount St. Helens location.

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Fade between a SMS-2 Visible and Infrared band.

Note that there is a geolocation offset between the two spectral bands. The satellite times listed are the image scan start times.

GOES-3

The experimental SMS series followed the ATS series, and was a precursor to the operational GOES.

GOES -3 also observed both volcanic ash plumes.

A slightly longer GOES-3 infrared animation is available here. NASA SMS-2 and NOAA GOES-3 data are via the University of Wisconsin-Madison SSEC Satellite Data Services.

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the formation of a pyrocumulonimbus (pyroCb) cloud that was spawned by the Bringham Fire in extreme eastern Arizona during the afternoon hours on 11 June 2020. To be classified as a pyroCb, the deep convective cloud must be generated by a large/hot fire, and eventually exhibit cloud-top 10.35 µm infrared brightness temperatures of -40ºC and colder — assuring the heterogeneous nucleation of all supercooled water droplets to form ice crystals. The pyroCb cloud then moved northeastward across far western New Mexico.

In Shortwave Infrared imagery, the fire’s thermal anomaly or “hot spot” was depicted by the cluster of red pixels — and the pyroCb cloud tops  appear warmer (darker gray) than those of nearby conventional thunderstorms, due to enhanced reflection of solar radiation off the smaller ice crystals found in the pyroCb anvil (reference).

The pyroCb exhibited minimum cloud-top 10.35 µm infrared brightness temperature in the -40 to -49ºC range (shades of blue) — according to rawinsonde data from Tucson, Arizona at 00 UTC on 12 June (below), this roughly corresponded to altitudes of 10-12 km.

 

A Suomi NPP VIIRS True Color Red-Green-Blue (RGB) image viewed using RealEarth (above) included plots of VIIRS Fire Radiative Power. The hazy signature of smoke drifting northward was apparent in the image. In fact, a plot of surface observation data at Springerville, Arizona (KJTC) (below) indicated that surface visibility was eventually reduced to 7 miles around 23 UTC as strong southerly winds advected smoke northward from the fire.

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GOES-16 (GOES-East) Split Cloud Top Phase (11.2-8.4 µm) and Dust Red-Green-Blue (RGB) images (above) displayed signatures of blowing dust plumes — medium shades of blue in the 11.2-8.4 µm product, and brighter shades of magenta to pink in the Dust RGB — caused by strong winds in the wake of cold fronts moving southward and eastward  across the central and southern Plains on 09 June 2020.

A closer view of GOES-16 Dust RGB images over the Texas Panhandle (below) showed a localized pocket of dense blowing dust moving southeastward — it temporarily reduced visibility to 2 miles at Borger KBGD, moved across Interstate 40 east of Amarillo KAMA, and then reduced visibility to 3 miles at Childress KCDS.

On a larger scale, a longer animation of GOES-16 Dust RGB images created using Geo2Grid (below) showed the early stages of the initial southward surge of blowing dust over eastern Colorado, where wind gusts to 102 mph were recorded.

The corresponding daytime GOES-16 True Color RGB mages (below) showed the tan-colored plumes of blowing dust, in addition to a few smoke plumes (shades of white) from wildfires in Arizona, New Mexico and the Texas Panhandle.

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GOES-16 (left) and GOES-17 (right) Band 2 (0.64 µm) Visible imagery, 2140 UTC on 8 June 2020 through 0130 UTC 9 June 2020

 

Strong convection developed over Nebraska late in the afternoon of June 8th (SPC Storm reports are here).  Mesoscale domains from both GOES-16 and GOES-17 viewed this developing convection, enabling fine spatial and temporal-scale viewing of the convection.  (Past Mesoscale domain sectors can be searched at this website; this website shows locations in the past year.)

 

The stereoscopic mp4 animation (created using geo2grid and ffmpeg;  a similar blog post on this technique is here) above captures the convective development near 2200 UTC on the 8th, and follows the storm evolution through sunset.  To view the imagery in three dimensions, cross your eyes until three images are present, and focus on the image in the middle.

A 2-panel comparison of GOES-17 and GOES-16 Visible images during the period 2230-0208 UTC is shown below, with time-matched plots of SPC Storm Reports. The images are displayed in the native projection of each satellite.

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Two other animations (mp4s with imagery every minute from the mesoscale sector), courtesy of Tim Schmit, NOAA/STAR, show the evolution over Nebraska on this day. This one shows the GOES-17 visible imagery from sun-rise through late afternoon; stable wave clouds are evolve into the strong convection noted above. A second animation shows the evolution of the Convection RGB from 2100 UTC on 8 June through 0159 UTC on 9 June. This event is also featured in the CIRA Image of the day (link).

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