CALIOP Clear-Sky Constrained Aerosol Extinction Profiles MERRA2 Version 1

These retrievals leverage column aerosol optical depth (AOD) obtained from the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), which assimilates AOD observations from MODIS, MISR, and AERONET. The dataset spans daytime and nighttime observations over both land and ocean from 2006 to 2023.

Traditional CALIOP aerosol extinction retrievals rely on lidar ratios, introducing significant uncertainties (~30–50%). By substituting lidar ratios with column AOD, we computed constrained aerosol extinction profiles using CALIOP attenuated backscatter data. These profiles were validated against more than 150 coincident airborne High Spectral Resolution Lidar (HSRL) datasets, showing strong agreement with mean bias differences within 0.01 km⁻¹ (10%).