Cold Air Outbreaks in Fram Strait: Climatology, Trends, and Observations During an Extreme Season in 2020

Sandro.Dahlke [ at ]


Fram Strait in the northern North Atlantic is a key region for marine cold air outbreaks (MCAOs), southward discharges of polar air under northerly air flow, which have a strong impact on air-sea heat fluxes, boundary layer processes and severe weather. This study investigates climatologies and decadal trends of Fram Strait MCAOs of different intensity classes based on the ERA5 reanalysis product for 1979–2020. Among striking interannual variability, it is shown that the main MCAO season is December through March, when MCAOs occur around 2/3 of the time. We report on significant decadal MCAO decreases in December and January, and a significant increase in March. While the mid-winter decrease is mainly related to the different paces of warming between the surface and the lower atmosphere, the increase in March can be related to changes in synoptic circulation patterns. As an explanation for the latter, a possible feedback between retreating Barents Sea sea ice, enhanced cyclonic activity and Fram Strait MCAOs is postulated. Exemplifying the trend toward stronger MCAOs during March, the study details the recordbreaking MCAO season in early 2020, and an observational case study of an extreme MCAO event in March 2020 is conducted. Thereby, radiosonde observations are combined with kinematic air back-trajectories to provide rare observational evidence for the diabatic cooling and drying during the MCAO preconditioning phase.

Item Type
Primary Division
Primary Topic
Helmholtz Cross Cutting Activity (2021-2027)
Research Networks
Publication Status
Eprint ID
DOI 10.1029/2021JD035741

Cite as
Dahlke, S. , Solbès, A. and Maturilli, M. (2022): Cold Air Outbreaks in Fram Strait: Climatology, Trends, and Observations During an Extreme Season in 2020 , Journal of Geophysical Research-Atmospheres, 127 (3), pp. 1-18 . doi: 10.1029/2021JD035741

[thumbnail of Dahlke_et_al_2022.pdf]

Download (2MB) | Preview

Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Geographical region

Research Platforms

PS > 122/1 (MOSAiC20192020)
PS > 122/2 (MOSAiC20192020)
PS > 122/3 (MOSAiC20192020)
PS > 122/4 (MOSAiC20192020)
PS > 122/5 (MOSAiC20192020)

Edit Item Edit Item