Distributions of Condensation Nuclei, Cloud Condensation Nuclei and Cloud Properties over the Southern Ocean: Primary Results from MARCUS
Qing Niu is an MS student at the University of Oklahoma. Qing earned her BS in Atmospheric Sciences at Nanjing University in fall 2018. She then joined the School of Meteorology and the Cooperative Institute for Mesoscale Meteorology to pursue a masters degree under the guidance of Greg McFarquhar. Her research focused on cloud physics and microphysical processes.
Abstract
Climate models are significantly challenged by uncertainties and bias in representing South Ocean (SO) clouds and aerosols and requires a better physical understanding of Aerosol-Cloud Interactions (ACIs). Arguable, the Southern Ocean (SO) provides the most pristine conditions on Earth for examining ACIs for liquid, ice and mixed-phase clouds. The Atmospheric Radiation Measurement Program’s Mobile Facility-2 (AMF2) onboard the Australian icebreaker Aurora Australis (AA) provided ship-based cloud, precipitation and aerosol measurements during the Measurements of Aerosols, Radiation and CloUds over the SO (MARCUS) Experiment. With Machine Learning Classifier and an algorithm using median of the absolute deviations from the median, time periods when there was contamination from the ship stack were identified. UHSAS (Ultra High Sensitivity Aerosol Spectrometer measures aerosol number distribution function for 60nm gt D lt 1000nm vestigial, analysis of measurements of condensation nuclei (CN) revealed that particles in the Aitken mode (with particle diameter D lt 100nm) significantly dominated number concentrations, a few relatively large coarse particles (gt 350nm) also occurred though. To better understand the sources and sinks of aerosols and aerosol-cloud interaction, probability distribution functions of surface accumulation mode aerosols and CCN are analyzed as functions of wind speed, inversion strength, boundary layer depth, Convective Available Potential Energy (CAPE) and degree of coupling between the cloud and boundary layer. Further, the relationships between aerosol and cloud properties will be examined as a function of the same environmental conditions.