Description¶
“[...], the HALO–(AC)³ aircraft campaign was conducted over the Norwegian and Greenland seas, the Fram Strait, and the central Arctic Ocean in March and April 2022. The campaign focused on one specific challenge posed by the models, namely the reasonable representation of transformations of air masses during their meridional transport into and out of the Arctic via northward moist- and warm-air intrusions (WAIs) and southward marine cold-air outbreaks (CAOs). Observations were made over areas of open ocean, the marginal sea ice zone, and the central Arctic sea ice. Two low-flying and one long-range, high-altitude research aircraft were flown in colocated formation whenever possible. To follow the air mass transformations, a quasi-Lagrangian flight strategy using trajectory calculations was realized, enabling us to sample the same moving-air parcels twice along their trajectories. Seven distinct WAI and 12 CAO cases were probed.” (Wendisch et al., 2024)
Publications¶
Data overview paper: Ehrlich et al., 2025: A comprehensive in situ and remote sensing data set collected during the HALO-(AC)³ aircraft campaign
Synoptic overview paper: Walbröl et al., 2024: Contrasting extremely warm and long-lasting cold air anomalies in the North Atlantic sector of the Arctic during the HALO-(AC)³ campaign
Platforms¶
Instruments¶
HALO¶
BACARDI
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BAHAMAS
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Dropsondes
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HAMP
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SMART
SMART-HALO
During HALO-(AC)³ SMART was configured with only one inlet with a hemispheric field of view, which was mounted on top of the fuselage to measure the spectral downward irradiance between 320nm and 2100nm wavelength.
specMACS
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VELOX
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WALES
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P5¶
Overview of Flights¶
Involved Projects¶
Further Publications¶
- Wendisch, M., Crewell, S., Ehrlich, A., Herber, A., Kirbus, B., Lüpkes, C., Mech, M., Abel, S. J., Akansu, E. F., Ament, F., Aubry, C., Becker, S., Borrmann, S., Bozem, H., Brückner, M., Clemen, H.-C., Dahlke, S., Dekoutsidis, G., Delanoë, J., … Zinner, T. (2024). Overview: quasi-Lagrangian observations of Arctic air mass transformations – introduction and initial results of the HALO–(𝒜 𝒞) 3 aircraft campaign. Atmospheric Chemistry and Physics, 24(15), 8865–8892. 10.5194/acp-24-8865-2024
- Ehrlich, A., Crewell, S., Herber, A., Klingebiel, M., Lüpkes, C., Mech, M., Becker, S., Borrmann, S., Bozem, H., Buschmann, M., Clemen, H.-C., De La Torre Castro, E., Dorff, H., Dupuy, R., Eppers, O., Ewald, F., George, G., Giez, A., Grawe, S., … Wendisch, M. (2025). A comprehensive in situ and remote sensing data set collected during the HALO–(𝒜 𝒞) 3 aircraft campaign. Earth System Science Data, 17(3), 1295–1328. 10.5194/essd-17-1295-2025
- Walbröl, A., Michaelis, J., Becker, S., Dorff, H., Ebell, K., Gorodetskaya, I., Heinold, B., Kirbus, B., Lauer, M., Maherndl, N., Maturilli, M., Mayer, J., Müller, H., Neggers, R. A. J., Paulus, F. M., Röttenbacher, J., Rückert, J. E., Schirmacher, I., Slättberg, N., … Crewell, S. (2024). Contrasting extremely warm and long-lasting cold air anomalies in the North Atlantic sector of the Arctic during the HALO-(𝒜 𝒞) 3 campaign. Atmospheric Chemistry and Physics, 24(13), 8007–8029. 10.5194/acp-24-8007-2024
- Röttenbacher, J., Ehrlich, A., Schäfer, M., Kirbus, B., Luebke, A. E., & Wendisch, M. (2023). Aircraft measurements of spectral downward solar irradiance over Arctic sea ice and ocean during the HALO-(AC)3 campaign in spring 2022. PANGAEA. 10.1594/PANGAEA.956151