Ground-based Remote Sensing of Aerosol, Clouds, Dynamics, and Precipitation in Antarctica - First results from the one-year COALA campaign at Neumayer Station III in 2023

• Published in: Bulletin of the American Meteorological Society
• Main Authors: Radenz, Martin, Engelmann, Ronny, Henning, Silvia, Schmithüsen, Holger, Baars, Holger, Frey, Markus M., Weller, Rolf, Bühl, Johannes, Jimenez, Cristofer, Roschke, Johanna, Muser, Lukas Ole, Wullenweber, Nellie, Zeppenfeld, Sebastian, Griesche, Hannes, Wandinger, Ulla, Seifert, Patric
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Meteorological Society 2024
• Subjects: Antarc*; Antarctic; Antarctica; Dronning Maud Land; Ice Shelf
• Online Access: http://nora.nerc.ac.uk/id/eprint/537605/; https://nora.nerc.ac.uk/id/eprint/537605/1/bams-BAMS-D-22-0285.1%20%281%29.pdf; https://journals.ametsoc.org/view/journals/bams/aop/BAMS-D-22-0285.1/BAMS-D-22-0285.1.xml

Novel observations of aerosol and clouds by means of ground-based remote sensing have been performed in Antarctica over the Ekström ice shelf on the coast of Dronning Maud Land at Neumayer Station III (70.67°S, 8.27°W) from January to December 2023. The deployment of OCEANET-Atmosphere remote-sensing observatory in the framework of the Continuous Observations of Aerosol-cLoud interAction (COALA) campaign brought ACTRIS aerosol and cloud profiling capabilities next to meteorological and air chemistry in-situ observations at the Antarctic station. We present an overview of the site, the instrumental setup and data analysis strategy and introduce 3 scientific highlights from austral fall and winter, namely: 1. Observations of a persistent mixed-phase cloud embedded in a plume of marine aerosol. Remote-sensing-based retrievals of cloud-relevant aerosol properties and cloud microphysical parameters confirm that the free-tropospheric mixed phase cloud layer formed in an aerosol-limited environment. 2. Two extraordinary warm air intrusions. One with intense snowfall produced the equivalent of 10% of the yearly snow accumulation, a second one with record-breaking maximum temperatures and heavy icing due to supercooled drizzle. 3. Omnipresent aerosol layers in the stratosphere. Our profiling capabilities could show that 50% of the 500-nm aerosol optical depth of 0.06 was caused by stratospheric aerosol, while the troposphere was usually pristine. As demonstrated by these highlights, the one-year COALA observations will serve as a reference dataset for the vertical structure of aerosol and clouds above the region, enabling future observational and modeling studies to advance understanding of atmospheric processes in Antarctica.