April 7, 2020
April 7, 2020
CategoriesWeather and Climate Systems
Note: As part of the Spring 2020 the online framework, BUL seminars are offered live only to enrolled students and the speaker’s adviser(s) and committee. The live sessions are recorded and made available via the seminar’s mailing list and the BUL website.
Distributions of Condensation Nuclei, Cloud Condensation Nuclei and Cloud Properties over the Southern Ocean: Primary Results from MARCUS
Qing Niu – M.S. Student, School of Meteorology/CIMMS
RECORDING AVAILABLE HERE: https://youtu.be/SAIRFBhaZj8
Questions can be directed to the speaker at email@example.com
Co-authors: Greg McFarquhar, Saisai Ding, Roger Marchand, Adam Theisen, Ruhi Humphries
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 < D < 1000nm vestigial, analysis of measurements of condensation nuclei (CN) revealed that particles in the Aitken mode (with particle diameter D<100nm) significantly dominated number concentrations, a few relatively large coarse particles (>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.