The HALO-(AC)³ measurement campaign aims to investigate the processes causing the drastic climate changes in the Arctic. The Arctic temperature increase, with over 3°C in the last 50 years, is much more pronounced than the changes in other regions of the Earth and impacts the regional climate system, e.g., sea ice loss. This phenomenon is called „Arctic Amplification.“ The focus of the campaign is to study warm air intrusions into the central Arctic as well as cold air outbreaks from the Arctic. These events may not only amplify Arctic warming via feedback effects (positive feedback), but also influence our mid-latitude weather through meridional heat and moisture transports.

The field campaign will take place from March 5 to April 15, 2022, spread over 3 sites. The HALO research aircraft will be based in Kiruna, Sweden for the full period. Polar aircraft Polar 5 & Polar 6 will operate from Longyearbyen, Svalbard, during the period March 16 to April 13, 2022, and balloon measurements will take place in Ny-Ålesund, Svalbard, covering about 8 weeks in March extended to May 2022. The measurements will focus on an area in the Northern Arctic Ocean and Fram Strait and around Svalbard (78°N, 16°E).

HALO-(AC)³ is a research campaign jointly performed by the University of Leipzig, the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, the German Aerospace Center, the Leibniz Institute for Tropospheric Research, the Max Planck Institutes for Meteorology and Chemistry, as well as the Universities of Bremen, Cologne, Hamburg, Mainz and the Ludwig Maximilian University of Munich and international partners. More than 100 researchers from 12 countries will participate in the research project. The campaign name HALO-(AC)³ embraces the lead research projects HALO-SPP (High Altitude and Long Range Research Aircraft – Priority Program) and the Collaborative Research Center/Transregio Arctic Amplification (AC)³ (Arctic Amplification: Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms).

Further information can be found at