Relationship between macrophysical and microphysical properties of mixed-phase and ice clouds over the Southern Ocean and Antarctica

 

Author

Minghui Diao — San Jose State University

Category

High-latitude clouds and aerosols

Description

Mixed-phase and ice clouds play very important roles in regulating atmospheric radiation over the Southern Ocean and Antarctica. Previously, ground-based and in-situ observations over this remote region are very limited, and a few of the existing observation-based analyses mainly focused on the microphysical properties of clouds. Relationships between macrophysical and microphysical properties for both mixed-phase and ice clouds have not been thoroughly investigated. In this work, we will use the DOE ARM ground-based observations at Antarctica and two NSF flight campaigns over the Southern Ocean, to examine cloud macrophysical and microphysical properties on the microscale to mesoscale. Three datasets to be used in this work are: DOE ARM West Antarctic Radiation Experiment (AWARE) campaign based at the McMurdo station at Antarctica (2016 – 2017), the NSF O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) Study campaign based at Punta Arenas, Chile (2016), and the NSF Southern Ocean, Clouds, Radiation, Aerosol, Transport Experimental Study (SOCRATES) campaign based at Hobart, Australia (2018). The cloud characteristics to be examined include the spatial distributions of cloud phases, the characteristic cloud chord length, patchiness of clouds, and spatial ratios of liquid phase, mixed phase and ice phase in adjacent cloudy segments. These macroscopic properties will be analyzed in relation to thermodynamic and dynamical conditions, such as the average and maximum relative humidity inside clouds, vertical velocity, and temperature fluctuations.