Evaluation of the Diurnal Variability of Aerosol Properties Observed By the DSCOVR/EPIC Instrument

Abstract:

We present an evaluation analysis of aerosol properties retrieved using quasi-hourly observations of near UV radiances (340 and 388 nm) by the Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory (DSCOVR) satellite stationed at the Lagrange 1 point 1.5 × 10⁶ km from the Earth. DSCOVR’s orbital configuration makes it possible to obtain hourly estimates of aerosol optical depth (AOD) and single scattering albedo (SSA) from near-sunrise to near-sunset over the sunlit disk of the Earth. AERONET and SKYNET ground-based multiple daily measurements of these parameters are used to examine the accuracy of their retrieved diurnal cycle. In this analysis we use AERONET and SKYNET observations over multiple sites representative of most abundant aerosol types such as biomass burning, arid and semi-arid, urban and industrial polluted areas. The EPIC observed diurnal patterns of retrieved parameters are well characterized for most of sites except for early morning or late afternoon hours when known geo-location inaccuracies are associated with larger retrieval uncertainty.