Mount Tongariro in New Zealand (on the North Island) erupted on Monday, August 6th, for the first time in a century. A Suomi-NPP overpass at 12:52 UTC, approximately one hour after the eruption, allowed the day-night band to capture an image of the volcanic plume as it moved eastward across... Read More

The Visible-Infraread Imager Radiometer Suite (VIIRS) instrument on Suomi/NPP samples longwave radiation emitted at 11.45 µm and shortwave radiation emitted at 3.74 µm. Because liquid water clouds have different emissivity properties at those two wavelengths, the difference in brightness temperature can be used to determine the presence of clouds (such... Read More