A Comparison of Aerosol and Cloud Properties Observed By Multiple Lidar Systems at the ARM SGPSite

The Atmospheric Radiation Measurement (ARM) program operates multiple lidar system at the Southern Great Plains (SGP) site in Oklahoma. The Raman Lidar (RL) at SGP has been operational from last three decades. Since the first measurement in early 1990s, the RL system has been upgraded multiple times. The last upgrade was in 2015 and since then it has been collecting data with the same configuration. Aerosol and cloud properties are being retrieved using the ARM Raman Lidar Profile Feature detection and EXtinction (RLPROF-FEX) Value Added Product. This product provides estimates of particulate backscatter, cloud phase, feature classifications, and related fields (Thorsen et al., 2015, Thorsen and Fu 2015; Chand et al., 2019: https://www.arm.gov/publications/tech_reports/doe-sc-arm-tr-224.pdf). The RLPROF-FEX requires careful attention to the set up and configurations of several measured variables by the RL. As a supplementary measurement to RL and other Lidars, the High Spectral Resolution Lidar (HSRL) was deployed at the SGP site starting from Aug 25, 2020, to May 12, 2021. In this presentation, we plan to compare backscatter and cloud base heights (CBH) from multiple Lidars [RL, HSRL, Doppler Lidar, Micro Pulse Lidar, and Ceilometer], and linear depolarization ratios between the RL and the HSRL during the HSRL operational period. Estimates of CBH (Newsom et al., 2017 https://www.arm.gov/publications/tech_reports/doe-sc-arm-tr-189.pdf), and vertical distribution of aerosols and clouds features will provide additional insight into the uncertainties of various retrievals. Such inter-comparisons are important to understand the capabilities and performance limitations of remote sensing systems under varying atmospheric conditions.