Cloud Properties and Radiative Effects Under a Biomass Burning Aerosol Layer: A Perspective from Transmitted Light

Typically, remotely sensed cloud properties are obtained via reflected light at cloud top by satellites. For cases where there is an overlying aerosol layer, this may cause some biases in retrieved cloud properties. Here we showcase cloud properties under an aerosol layer retrieved using transmitted instead of reflected light. Light transmitted through clouds is sensitive to a different cloud volume than reflected light at cloud top. This difference in sampling volumes has implications when calculating cloud radiative effects (CRE). We present early results from the NASA ObseRvations of CLouds above Aerosols and their intEractionS (ORACLES) field campaign, which recently concluded its first deployment sampling clouds and overlying biomass burning aerosol layers from the airborne NASA P3 platform. We present results from the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR), in conjunction with the Solar Spectral Flux Radiometers (SSFR). During this deployment, 4STAR sampled cloud-transmitted solar light via zenith measurements. We focus on the zenith-viewing scattered light measurements used to retrieve cloud optical thickness, effective radius, and thermodynamic phase of clouds under a biomass burning layer. We contrast reflection based approaches used by satellites to the transmission-based approach used by 4STAR during ORACLES for retrieving cloud properties and their CRE. In addition to the preliminary retrievals of cloud properties, we present the impact of the overlying aerosol on CRE.