3,4,5,6,2,7,8,1,2,9,4,4,10,4,1,1,10,11,2,10- 1Leibniz Institute for Tropospheric Research, Atmospheric Microphysics, Leipzig, Germany (poehlker@tropos.de)
- 2Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
- 3School of Physical and Chemical Sciences University of Canterbury, Christchurch, New Zealand
- 4Max Planck Institute for Chemistry, Mainz, Germany
- 5The Air Quality Collective, Auckland, New Zealand
- 6Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, Frankfurt, Germany
- 7Center for Atmospheric Particles Studies, Carnegie Mellon, University, Pittsburgh, USA
- 8Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, USA
- 9Karlsruhe Institute of Technology, Karlsruhe, Germany
- 10German Aerospace Center, Institute of Atmospheric Physics, Wessling, Germany
- 11Institute of Atmospheric Physics, University Mainz, Mainz, Germany
The Southern Ocean (SO) is one of the cloudiest regions on Earth. However, cloud radiative effects are not well represented over the SO in atmospheric models, which is mainly due to an underestimation of aerosols. To address this and other fundamental and pressing open questions on the interaction of atmospheric radiation, aerosol nucleation and growth, cloud formation and impacts over the SOI, the HALO-South aircraft mission was conducted in September and October 2025 based in Christchurch, Aotearoa New Zealand. HALO stands for High Altitude and Long Range Research Aircraft. HALO-South covered the full cycle of processes from aerosol formation, cloud evolution, and radiative interaction with a special focus on the characteristics and effects of mixed-phase clouds. The instrumental payload of HALO included a unique and comprehensive in-situ and remote sensing suite of instruments. It was designed to collect data to improve our understanding of fundamental atmospheric processes and to extrapolate and upscale the results using satellite data and global climate models in order to resolve long-standing measurement-modelling discrepancies. In addition, the ground-based stations in Tāwhaki and Invercargill with remote sensing and in-situ long term measurements will extend the data to a larger scale in time. The first analysis of the campaign shows promising insights into cloud and aerosol processes over the SO, which will be presented and discussed.
Acknowledgments: This work was supported by the DFG (Deutsche Forschungsgemeinschaft, German Research Foundation) Priority Program SPP 1294, the Max Planck Society, Priority Program SPP 1294, the German Aerospace Center (DLR)
How to cite: Pöhlker, M. L., McDonald, A., Chang, Y., Coulson, G., Curtius, J., Ehrlich, A., Gordon, H., Henning, S., Kalesse-Los, H., Möhler, O., Mertes, S., Pöhlker, C., Pöschl, U., Sauer, D., Schneider, J., Seifert, P., Stratmann, F., Voigt, C., Wendisch, M., and Ziereis, H.: The interplay of Clouds, Aerosols, and Radiation above the Southern Ocean, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16802, https://doi.org/10.5194/egusphere-egu26-16802, 2026.
