Lunar Eclipse effects on the Day Night Band
Imagery from the VIIRS Today website, shown below, shows the stark effects of the Lunar Eclipse on Day Night Band imagery. Suomi NPP and NOAA-20 passes over the east coast (shown below; it happened with NOAA-21 too!) lack the reflected moonlight that was available over the central/western United States after the lunar eclipse had ended. This will happen again on September 7th this year. Mark your calendars.
Suomi-NPP overflew the eastern USA around 0720 UTC; NOAA-20 overflew around 0745 UTC; NOAA-21 overflew around 0700 UTC.
Contrast, below, NOAA-21 overpasses (imagery taken from the CIMSS VIIRS Viewer) at 0651 and 0831 UTC. With no reflected lunar illumination in the earlier overpass, aurora over northern Canada are far easier to view (Note also the lightning streaks over the ocean). It’s a bit harder to see the full extent of the aurora in the more illuminated overpass at 0831 UTC.
Bob Carp, SSEC, created the following animation using McIDAS-V. It shows swaths from Suomi-NPP, NOAA-20 and NOAA-21. You’ll see that DNB imagery is starting to dim at 0507 UTC and starts to brighten up by 0832 UTC. This website gives times when the effects of the eclipse were expected: The penumbral part of the eclipse was from 0357 UTC to 1000 UTC; a partial eclipse was from 0509 UTC to 0847 UTC; totality was from 0626 UTC to 0731 UTC.
In addition, shown below is a similar animation (created using AWIPS) that steps through Day/Night Band images from Suomi-NPP + NOAA-21 (white labels) and NOAA-20 (cyan labels).
VIIRS Day/Night Band images from Suomi-NPP + NOAA-21 (white labels) and NOAA-20 (cyan labels) [courtesy Scott Bachmeier, CIMSS; click to enlarge]