EMS Annual Meeting Abstracts
Vol. 18, EMS2021-4, 2021, updated on 18 Jun 2021
EMS Annual Meeting 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Wintertime temperature extremes in the high Arctic: drivers, statistics and implications for the mid-latitudes

Gabriele Messori1,2, Cian Woods2, Ryoto Wada3, and Rodrigo Caballero2
Gabriele Messori et al.
  • 1Department of Earth Sciences and Centre of Natural Hazards and Disaster Science (CNDS), Uppsala University, Uppsala, Sweden (gabriele.messori@geo.uu.se)
  • 2Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
  • 3Department of Ocean Technology, Policy and Environment, University of Tokyo, Japan

Temperature extremes in the high Arctic have made the headlines in recent years, with wintertime warm spells approaching 0 °C at the North Pole. In the first part of this presentation, I will outline some salient large-scale and synoptic atmospheric drivers of wintertime warm and cold spells in the high Arctic. The warm spells are systematically associated with a large-scale circulation pattern that creates a natural pathway for extreme moisture intrusions from the Atlantic sector into the Arctic. Anomalies in the distribution of synoptic cyclones then favour a deep penetration of these intrusions across the Arctic basin. The large-scale circulation pattern associated with the warm spells further favours the advection of cold air across central-northern Eurasia. On the contrary, cold Arctic extremes are associated with a persistent low-pressure system over the pole. This effectively isolates the high latitudes from mid-latitude air masses, favouring an intense radiative cooling of the polar region. In the second part of the presentation, I will discuss return times of the wintertime warm spells, using a novel approach grounded in extreme value theory. This approach explicitly takes into account the spatial structure of the moisture intrusions driving the temperature extremes, and I will try to convince you that it provides a more realistic set of estimates than conventional return-time algorithms.

How to cite: Messori, G., Woods, C., Wada, R., and Caballero, R.: Wintertime temperature extremes in the high Arctic: drivers, statistics and implications for the mid-latitudes, EMS Annual Meeting 2021, online, 6–10 Sep 2021, EMS2021-4, https://doi.org/10.5194/ems2021-4, 2021.


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