Chasing the Shadows with the VIIRS Day/Night Band

The Day/Night Band (DNB) is a low-light visible (500-900 nm bandpass) radiometer included on the Visible/Infrared Imaging Radiometer Suite (VIIRS). It is carried on the Suomi National Polar-orbiting Partnership (NPP), launched in Fall 2011 as a risk-reduction satellite to the Joint Polar Satellite System (JPSS), the first member of which (JPSS-1) is slated for launch in Fall of 2017. Standing as one of the most novel innovations to the National Oceanic and Atmospheric Administration’s next-generation polar-oribitng program, the DNB has revolutionized the way we observe the nocturnal environment from space. By virtue of its extremely high sensitivity (extending down to illumination levels ten million times fainter than sunlight), the Day/Night Band provides a unique ability to utilize light signals from non-traditional sources, both natural and artificial. These sources include moonlight, city lights, and even atmospheric nightglow, providing insight to myriad surface and atmospheric properties. Immediate and powerful impacts of Day/Night Band to high-latitude users led to designation of Near-Constant Contrast (NCC) imagery as a Key Performance Parameter (KPP) of the JPSS program, ensuring the inclusion of the DNB on future members of the JPSS constellation.

This presentation highlights progress made to date on advancing the awareness, scope, and overall utility of the Day/Night Band in the research and operational communities. Through Pursuit of the the Shadows, a JPSS Program Office sponsored research project dedicated to showcasing and socializing the relatively new (compared to decades of infrared-only nighttime observations) low-light visible measurements, the many utilities of the unique DNB observations are being brought to light. An important development in this information discovery coincides with the addition of JPSS-1. The new satellite will be placed in the same orbital plane as Suomi, displaced by ½ orbit (ahead). This configuration will allow for partial overlap of the VIIRS 3000 km wide swath at all latitudes, displaced in time by ~50 min. The dual DNB system will enable monitoring of light changes a mid/low latitudes, including ship movement, fire line advances, cloud property evolution, and the propagation of sustained gravity wave features in nightglow (e.g., mesospheric bores and concentric waves atop strong isolated and organized convection).