Seasonal Change in Satellite-Retrieved Lower-Tropospheric Ice-Cloud Fraction Over the Southern Ocean

Abstract

This study investigated the temperature and fraction of lower-tropospheric ice cloud over Antarctica and the Southern Ocean (SO) using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite data. Over the SO, the maximum low-level ice-cloud fraction below 2 km is observed at cold temperatures ( −7.5°C (>−17.5°C) during summer (winter). High fractions of low-level ice cloud observed at higher temperatures over near-coastal Antarctic sea ice areas in summer, coincident with the highest chlorophyll-a concentrations, and over coastal Antarctic ice-covered areas in winter, suggest that marine aerosols act as ice-nucleating particles for ice-cloud formation during summer and winter.