Return to the Dark Side: Visible Applications in Dark Environments, Revisited (VADER)

Visible light satellite imagery is indispensable to daytime operational weather forecasting. Whereas these same needs and benefits exist at night, the traditional lack of nighttime visible-light imagery has imparted a sense of normalcy to the purely infrared-based paradigm. The introduction of the Visible/Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) on the Suomi National Polar-orbiting Partnership (S-NPP) has begun a dramatic shift to this paradigm, but the coarse temporal refresh of polar-orbiting satellites to real-time environmental situational awareness has relegated its greatest operational impacts to the high latitudes (e.g., poleward of 60° N), where revisits from polar orbiters are inherently more frequent. For this region, DNB imagery was designated post-launch as a Key Performance Parameter (KPP) by the Joint Polar Satellite System (JPSS) program. Since late 2017, the sampling situation for the DNB has improved for the lower-48 of the U.S. and Hawaii, as the JPSS program expanded with the successful insertion of NOAA-20, ½-orbit (~50 min) ahead of S-NPP in the same orbital plane. The revisit enabled by this satellite pair offers new opportunities to characterize features through motion/change and dual viewing perspective.

Here, we present an overview and early results from a JPSS-sponsored research project (Visible Applications in Dark Environments, Revisited—VADER) that aims to socialize and capitalize on the potential of the VIIRS/DNB observing system for the benefit of the research and operational communities. VADER targets key environmental awareness needs of commerce and transportation (surface/aviation/maritime), infrastructure (e.g., power consumption), and scientific algorithm development (clouds, aerosol, land, and ocean), mapping to DNB capabilities to artificial (ship lights, city lights, gas flares) and natural (e.g., lunar reflection, active fires, airglow) sources of nocturnal light. Specific topics include identification of false low clouds in infrared-based cloud masks, DNB-unique research tied to nightglow gravity waves, and disaster-triggered power outages.

Leveraging the novel tandem-DNB observations and the diverse signals of the night, VADER positions the JPSS program on the frontiers of science and discovery, while aligning practically with NOAA’s Strategic Goal for a Weather Ready Nation.