No, VIIRS did not capture a Donut dropping powdered sugar near the North Pole! On 12-13 Aug 2022, the VIIRS Snowmelt RGB revealed a Polar Mesoscale Cyclone depositing fresh snow across the Arctic, which was apparent under the clear skies in its wake (Fig 1 and 2). The unique combination of spectral channels, not available on GOES-R series ABI, allows for one to differentiate fresher snow cover from older snow cover and ice (see other examples here and here). In this case, the most recent snow cover is obvious as a trail of a relatively lighter shade of blue atop the darker shades of the older snow cover. In fact, one may note three distinct shades of blue, or snow ages, in this domain. The background/oldest snowpack on ice appears as the darkest shade of blue, the most recent swath the lightest, and a series of swaths perpendicular to the recent swath that exhibit shades of blue somewhere in the middle (Fig 3).
The Snowmelt RGB can be useful operationally, including at lower latitudes, for determining the type of precipitation that has fallen (rain, snow, freezing rain), assessing the blowability or runoff/flooding potential of snow cover, and as a tool to determining cloud microphysics. The VIIRS Snowmelt RGB can be viewed online at the CIRA SLIDER, and very soon, to a CIRA SLIDER – VIIRS CONUS sector to better accommodate the viewing of VIIRS imagery over CONUS.
Bill Line (NESDIS/STAR), Curtis Seaman (CIRA), John Forsythe (CIRA), Carl Dierking (UA/GINA)