Accession Number:

AD1099918

Title:

Detecting Layer Height of Smoke Aerosols Over Vegetated Land and Water Surfaces Via Oxygen Absorption Bands: Hourly Results from Epic/Dscovr in Deep Space

Descriptive Note:

Journal Article - Open Access

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States

Report Date:

2019-06-20

Pagination or Media Count:

20.0

Abstract:

We present an algorithm for retrieving aerosol layer height ALH and aerosol optical depth AOD for smoke over vegetated land and water surfaces from measurements of the Earth Polychromatic Imaging Camera EPIC onboard the Deep Space Climate Observatory DSCOVR. The algorithm uses Earth-reflected radiances in six EPIC bands in the visible and near-infrared and incorporates flexible spectral fitting that accounts for the specifics of land and water surface reflectivity. The fitting procedure first determines AOD using EPIC atmospheric window bands 443, 551, 680, and 780 nm, then uses oxygen O-2 A and B bands 688 and 764 nm to derive ALH, which represents an optical centroid altitude. ALH retrieval over vegetated surface primarily takes advantage of measurements in the O-2 B band. We applied the algorithm to EPIC observations of several biomass burning events over the United States and Canada in August 2017. We found that the algorithm can be used to obtain AOD and ALH multiple times daily over water and vegetated land surface. Validation is performed against aerosol extinction profiles detected by the Cloud-Aerosol Lidar with Orthogonal Polarization CALIOP and against AOD observed at nine Aerosol Robotic Network AERONET sites, showing, on average, an error of 0.58 km and a bias of -013 km in retrieved ALH and an error of 0.05 and a bias of 0.03 in retrieved AOD. Additionally, we show that the aerosol height information retrieved by the present algorithm can potentially benefit the retrieval of aerosol properties from EPICs ultraviolet UV bands.

Subject Categories:

  • Atmospheric Physics
  • Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE