EPIC L2 Standard Cloud Products v03: Improvements and Assessments

The Earth Polychromatic Imaging Camera (EPIC) onboard the Deep Space Climate Observatory (DSCOVR) has been providing full disc observations of the sunlit side of the Earth since June 2015. EPIC images are captured on a 2Kx2K CCD array that couples with a filter-wheel, enabling consecutive observations in 10 spectral channels ranging from the UV to the near-IR. One important contribution of EPIC is the ability to observe and retrieve key radiative properties of clouds, which are of critical importance for understanding the current climate system and for predicting climate. A suite of algorithms has been developed to generate the standard EPIC Level 2 Cloud Products that include cloud mask (CM), cloud effective pressure/height (CEP/CEH), cloud optical thickness (COT), etc. The EPIC cloud mask algorithm utilizes reflectance and channel ratio-based tests in the UV, VIS, and NIR, while cloud height is inferred from Oxygen A- and B-band observations and cloud optical thickness is retrieved using a single-channel technique (680 nm over land and 780nm over ocean). The most recent version of the EPIC L2 Cloud Products is v03. Compared to earlier versions, the cloud mask is significantly improved, especially over snow/ice covered land and over ocean sunglint areas through the innovative use of Oxygen A-band observations. In addition, the look-up-tables for Oxygen A- and B-band cloud height retrievals are also updated. Assessment show that the v03 cloud mask matches well with the co-located observations from low earth orbit and geostationary orbit satellites. The EPIC cloud products have been used in many applications, including trace gas retrieval correction, surface solar radiation analysis, cloud system study, cloud diurnal cycle analysis etc. In this presentation, future work on further improving the EPIC cloud products will also be discussed.