In a groundbreaking initiative to unravel the mysteries shrouding the Antarctic atmosphere, a consortium of leading scientific institutions—the Alfred Wegener Institute, Leibniz Institute for Tropospheric Research, and Max Planck Institute for Chemistry—has embarked on the SANAT flight campaign. This extensive research endeavor aims to illuminate the complex dynamics between aerosols and cloud formation over the icy expanse of Antarctica, extending research into regions deep within the continent where such studies have never ventured before.
The importance of Antarctica in regulating Earth’s climate system cannot be overstated. Its vast, reflective ice surfaces and the pervasive cloud cover play a pivotal role in reflecting incoming solar radiation back into space, a process integral to maintaining global temperature balance. Yet, despite its critical role, the microphysical processes underpinning cloud genesis in this polar environment have remained elusive, primarily due to logistical challenges and the scarcity of in-situ measurements. The SANAT campaign, leveraging state-of-the-art airborne instrumentation, marks the first comprehensive exploration of aerosol populations and their interactions with atmospheric trace gases over the Antarctic Plateau in two decades.
Central to cloud formation are aerosols—microscopic particles such as sea salt, mineral dust, soot, and other particulates—that act as condensation nuclei. Water vapor condenses onto these particles, giving rise to cloud droplets or ice crystals depending on ambient temperature and humidity conditions. Intriguingly, the Antarctic atmosphere contains a markedly lower aerosol load compared to most other regions on Earth. This sparse aerosol environment means even subtle changes in particle sources or composition could profoundly influence the microphysical properties of clouds, thereby altering the continent’s albedo and energy budget.
To bridge the existing knowledge gap, the SANAT campaign is investigating both natural and anthropogenic aerosol sources, their formation mechanisms, and their evolution at various altitudes as air masses traverse across oceans, ice shelves, and the interior Antarctic landscape. Dr. Zsófia Jurányi of the Alfred Wegener Institute leads this ambitious operation alongside Dr. Frank Stratmann of the Leibniz Institute for Tropospheric Research and Prof. Stephan Borrmann from the Max Planck Institute for Chemistry. Together, they are pioneering measurements that not only map the spatial distribution of aerosols but also characterize their ability to serve as cloud condensation nuclei (CCN) or ice nucleating particles (INP), critical parameters in cloud microphysics.
During January and February, the team conducted ten meticulously planned flights using the AWI’s Polar 6 research aircraft, navigating from the coastal Neumayer Station III deep into the interior towards the 80th parallel south—a region rarely accessed by scientific expeditions. These operations were conducted under stringent Antarctic conditions, demanding both technical precision and logistical expertise. While similar measurements focusing on coastal aerosol distribution were last conducted two decades prior, the SANAT campaign is distinguished by its deployment of cutting-edge instrumentation and its unprecedented penetration into the inner Antarctic atmospheric column.
Among the novel tools employed, the “T-Bird” instrument stands out. This towed probe, trailing behind Polar 6 on a 60-meter cable, autonomously gathers high-resolution data on aerosol characteristics independent of the aircraft’s immediate environment. By pairing T-Bird’s data with concurrent onboard measurements and ground-based observations at Neumayer Station III, researchers amassed a multidimensional dataset encompassing aerosol particle counts, size distribution, chemical composition, and meteorological parameters such as air temperature, pressure, and humidity.
Preliminary analyses have yielded unexpected revelations. Contrary to the long-standing assumption that aerosol concentrations plummet over the Antarctic Plateau, initial data indicate considerably higher particle densities with unique chemical signatures in the continent’s interior atmosphere. These findings challenge prior conceptions of Antarctic aerosol dynamics and suggest previously unrecognized local or transported sources contributing to this enhanced aerosol burden. Prof. Stephan Borrmann of the Max Planck Institute for Chemistry emphasized the complexity and novelty of these chemical compositions, underscoring the imperative to further dissect their origins and climatic implications.
Understanding aerosol-cloud interactions in Antarctica transcends mere academic interest. Given Antarctica’s integral position in the planetary climate system, modifying aerosol concentrations and cloud properties could have cascading effects on climate feedback mechanisms, influencing not only regional but also global weather patterns and climate trajectories. The SANAT campaign’s comprehensive data will enhance the parameterization of aerosol-cloud interactions within climate models, thus refining predictions and reducing uncertainties associated with future climate change scenarios.
Supporting the airborne campaign are parallel ground-based studies at Neumayer Station III, where continuous in-situ measurements of cloud condensation nuclei and ice nuclei have been conducted since 2019. Additionally, in 2023-2024, TROPOS implemented a year-long observational campaign deploying lidar and radar remote sensing techniques from a specially transported container. These ground-based initiatives complement the flight data, providing temporal context and validating airborne observations, thereby creating an integrated picture of Antarctic cloud microphysical properties.
The Polar 6, a modified Basler BT-67 aircraft, is engineered to withstand polar extremities while serving as a versatile flying laboratory. Operational since 2007 alongside its sister aircraft Polar 5, the outfitting of Polar 6 involves reconfiguring scientific instruments for each mission, enabling flexible data collection across a range of atmospheric, snow, and ice-related studies. In SANAT, the aircraft’s capability to penetrate austere and remote Antarctic airspace, coupled with sophisticated instrumentation, unlocks unparalleled access to a domain crucial for polar climate research.
As climate change continues to alter atmospheric circulation and surface conditions, the insights garnered from SANAT will be instrumental in deciphering aerosol transformations and their cloud-forming potentials in Antarctica’s pristine atmosphere. By merging observational rigor with interdisciplinary expertise, the campaign exemplifies a transformative leap forward in polar atmospheric sciences, promising to enrich our understanding of Earth’s coldest continent and its broader climatic significance.
The SANAT flight campaign thus represents a milestone achievement in Antarctic environmental research, marrying advanced airborne technology with strategic ground observations to fill a critical scientific void. Its findings are poised to recalibrate existing paradigms regarding aerosol-cloud interplay under extreme polar conditions and propel forward our capacity to anticipate climatic shifts emanating from this vital but remote region.
Subject of Research: Aerosol origin, transport, and interaction with clouds in the Antarctic atmosphere
Article Title: Unlocking Antarctica’s Atmospheric Secrets: The SANAT Flight Campaign’s Revolutionary Insights Into Aerosols and Cloud Formation
News Publication Date: Not specified
Web References: https://mediasvc.eurekalert.org/Api/v1/Multimedia/9aae80e6-5287-4cca-9c6e-a06fed60cbcd/Rendition/low-res/Content/Public
Image Credits: Philipp Joppe, MPI für Chemie
Keywords: Antarctica, aerosols, cloud formation, atmosphere, climate system, Polar 6, SANAT flight campaign, ice nuclei, cloud condensation nuclei, aerosol transport, atmospheric chemistry, polar research
