ICESat-2 Atmospheric Layer Feature Subtyping Using MERRA-2 Model Reanalysis

As a complement to its detailed altimetry products, basic atmospheric products, including calibrated backscatter profiles and cloud and aerosol layer detection, have also been developed for the Ice, Cloud, and Land Elevation Satellite 2 (ICESat-2). With the limitations of having a single 532nm wavelength without depolarization, feature subtyping is not feasible using heritage space-based lidar algorithms. To allow for further subtyping of these features, we sample Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis along the ICESat-2 orbit to allow for cloud phase and aerosol types to be assigned for detected layers. Using coincident points from intersecting orbits, we show that these model-assisted feature subtypes compare well to those determined by Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Expanding the atmospheric products from ICESat-2 to include cloud phase and aerosol type will allow for lidar ratios to be assigned, facilitating the future development of layer optical depths.