True-color RGB images from Terra MODIS, Suomi NPP VIIRS and Aqua MODIS, viewed using RealEarth (below) revealed the long ash plume during the late morning and early afternoon on 25 March. The dark signature of ash fall onto the snow-covered terrain was evident on the Terra and Aqua images, just west of the high-altitude ash plume.
GOES-16 Mesoscale Sector visible images: severe thunderstorms in Illinois/Indiana, and Tennessee/Georgia/South CarolinaMarch 20th, 2017 | Scott Bachmeier
1-minute interval 0.5-km resolution GOES-16 Visible (0.64 µm) images (above; also available as a 130 Mbyte animated GIF) showed a cluster of thunderstorms that moved southeastward across Illinois and Indiana, producing a swath of hail as large as 2.75 inches in diameter (SPC storm reports) on 20 March 2017. The shadowing and textured signature of overshooting tops could be seen in the vicinity of many of the hail reports (hail sizes, red, are plotted in 1/100th of an inch; 275 = 2.75 inches).
On 21 March, a larger-scale outbreak of wind and hail-producing thunderstorms developed which primarily impacted parts of Tennessee, Georgia and South Carolina. Trees falling on homes were responsible for injuries and a fatality in Georgia, and hail as large as 3.0 inches occurred in South Carolina (SPC storm reports). As discussed on the Satellite Liaison Blog, the co-location of both Mesoscale Sectors provided images at 30-second intervals — GOES-16 Visible (0.64 µm) images (below; also available as a 168 Mbyte animated GIF) again displayed very detailed cloud-top structure which included overshooting tops and gravity waves.
The ABI instrument on GOES-16 is able to scan 2 Mesoscale Sectors, each of which provides images at 1-minute intervals. For what was likely a prescribed burn in the Francis Marion National Forest (near the coast of South Carolina) on 19 March 2017, a comparison of 1 minute Mesoscale Sector GOES-16 and 15-30 minute Routine Scan GOES-13 Shortwave Infrared (3.9 µm) images (above; also available as a 50 Mbyte animated GIF) demonstrated the clear advantage of 1-minute imagery in terms of monitoring the short-term intensity fluctuations that are often exhibited by fire activity. In this case, the intensity of the fire began to increase during 15:15-15:45 UTC — a time period when there was a 30-minute gap in routine scan imagery from GOES-13. The GOES-16 shortwave infrared brightness temperature then became very hot (red enhancement) beginning at 15:46:58 UTC, which again was not captured by GOES-13 — even on the 16:00 UTC and later images (however, this might be due to the more coarse 4-km spatial resolution of GOES-13, compared to the 2-km resolution of the shortwave infrared band on GOES-16). Similar short-term intensity fluctuations of a smaller fire (burning just to the southwest) were not adequately captured by GOES-13.
The corresponding GOES-16 vs GOES-13 Visible image comparison (below; also available as a 72 Mbyte animated GIF) also showed the advantage of 1-minute scans, along with the improved 0.5-km spatial resolution of the 0.64 µm spectral band on GOES-16 (which allowed brief pulses of pyrocumulus clouds to be seen developing over the fire source region).The rapid south-southeastward spread of the smoke plume could also be seen on true-color Red/Green/Blue (RGB) images from Terra/Aqua MODIS and Suomi NPP VIIRS, as viewed using RealEarth (below).
Visible and thermal signatures of the Space-X EchoStar 23 rocket launch were seen with GOES-16 imagery on 16 March 2017. The set of 3 images above consists of 5-minute CONUS sector scans at 05:54:33 UTC (about 5 minutes before launch), 05:59:33 UTC (around launch time) and 06:04:33 UTC (about 5 minutes after launch). The 05:59:33 UTC image was actually scanning the NASA Kennedy Space Center (station identifier KXMR) area at 06:00:38 UTC, just after the 06:00 UTC launch time. A faint bright glow of the rocket booster was seen on the 0.5-km resolution Visible (0.64 µm) image; the 1-km resolution Near-Infrared (1.61 µm) rocket signature was much brighter, because this spectral band senses radiation from both visible and infrared portions of the electromagnetic radiation spectrum (which of the two was a stronger contributor to the bright signal is difficult to determine); the 2-km resolution Shortwave Infrared (3.9 µm) image displayed a warm (dark black enhancement) “hot spot”, although it was not exceptionally warm (with a 306.8 K maximum brightness temperature).
A “warm signal” was also observed on the three GOES-16 ABI Water Vapor bands: Lower-Level (7.3 µm), Mid-Level (6.9 µm) and Upper-Level (6.2 µm), as shown below. While water vapor is certainly a by-product of rocket booster combustion, it is important to remember that the Water Vapor bands are first and foremost Infrared bands that sense the brightness temperature of a layer of moisture (which can vary in both altitude and depth, depending on the temperature/moisture profile of the atmosphere and/or the satellite viewing angle). In this case, the atmosphere was relatively dry over the region, with little moisture aloft to attenuate the rocket signature — shifting the roughly-corresponding GOES-13 Sounder (had the GOES-13 Sounder instrument been operational) water vapor weighting functions (available from this site) to lower altitudes. However, moisture considerations aside, the rocket signature seen on the 05:59:33 UTC water vapor imagery was primarily a thermal anomaly.McIDAS-V images of GOES-16 Near-Infrared (1.6 µm and 2.2 µm) and Shortwave Infrared (3.9 µm) data at 05:59:33 UTC (below; courtesy of William Straka, SSEC) provided another view of the rocket launch signature.