Nighttime aerosol retrievals providing large spatial and temporal coverage, although critical to various studies including aerosol modeling, air quality and climate studies, currently do not exist.…

This is a grant awarded by the National Aeronautics and Space Administration (NASA) Shared Services Center to the University of North Dakota (UND) Division of Research & Economic Development for $483,096.00. The purpose of the grant is to develop new methods for retrieving nighttime aerosol optical depth data using NASA's Black Marble products and other satellite and ground-based observations. The goal is to improve the quality of NASA's Black Marble nighttime light products by quantifying and reducing aerosol-induced uncertainties. The proposed work will be evaluated through comparisons with lunar photometer and CALIOP spaceborne lidar measurements. This grant does not have a set-aside designation and is set to be completed by November 30, 2024. UND is a public research university in Grand Forks, North Dakota that has extensive experience conducting federal research and development projects across a wide range of disciplines.

Nighttime aerosol retrievals providing large spatial and temporal coverage, although critical to various studies including aerosol modeling, air quality and climate studies, currently do not exist. With the recent availability of calibrated nighttime observations of visible/near-infrared light from the visible/infrared imaging radiometer suite (viirs) day/night band (DNB), nighttime surface and artificial light source characteristics from the NASA black marble (leveraging viirs/DNB), a DNB-specific lunar illumination database, and newly released ground-based lunar photometer observations, IT is now feasible to investigate and evaluate methods for nighttime aerosol retrievals over large spatial domains. In this light, we propose to: (1) develop novel methods for nighttime aerosol optical depth retrievals using quality controlled NASA black marble products over regions with artificial light sources for both moonless and moon-illuminated nighttime observations. (2) construct an advanced vlidort-based linearized radiative transfer model for simulating TOA nighttime radiances and aerosol property jacobians (describing the sensitivity of observations to changes in aerosol parameters) for viirs DNB configurations. The new system will be applied for nighttime aerosol retrievals over regions with artificial light sources using similar approaches as those learned from (1), as well as over areas without artificial light sources, such as over oceans, using a single channel albedo-based approach, utilizing surface brdf as reported in the NASA black marble products. (3) as a feedback study, conduct research into the impacts of aerosol contamination in the NASA s black marble product suite. We will use the newly developed nighttime AOD data to quantify and reduce aerosol-induced uncertainties in NASA s black marble products (VNP46), leading to an improved suite of products for a variety of downstream surface and atmospheric applications. The proposed study will be evaluated rigorously by lunar photometer measurements, which have recently become available (january, 2019) from the NASA aeronet team, as well as through inter-comparisons with nighttime aerosol retrievals from caliop (spaceborne lidar).