Interaction of diabatic processes, large-scale eddies and the mean atmospheric circulation over the Atlantic, Arctic and Eurasia

Jaiser, Ralf and Handorf, Dörthe and Dethloff, Klaus (2019) Interaction of diabatic processes, large-scale eddies and the mean atmospheric circulation over the Atlantic, Arctic and Eurasia. Advances in Polar Science, 30 (2). pp. 81-92.

PDF Download (7MB)

Abstract

In the last decade, the atmospheric part of the climate system experienced a shift from pronounced zonal to stronger meridional flow configurations and regionally diverse changes and trends. The climate system shows complex interactions and nonlinear behavior, manifested in global warming, rising ocean temperatures and the retreat of Arctic sea ice. Although atmospheric trends and changes are observed, underlying processes are not well understood. In this study we diagnose the interaction of large-scale atmospheric eddies and the mean flow with respect to diabatic heating and cooling processes that impact on the atmospheric advection of heat. For this purpose, the three-dimensional Eliassen-Palm flux theory is used in combination with an analysis of the thermodynamic equation, diabatic heating and cooling and heat advection. The most recent decades of observed winter climate are evaluated in terms of climatology and trends over the Atlantic, Arctic and Eurasia. The change of the atmospheric circulation and related processes differ between early and late winter. In early winter, the interaction of macro-turbulent eddies with the mean flow is inhibited at the Atlantic jet stream entrance region and atmospheric heat is meridionally advected into the Arctic, both related to strong high pressure anomalies. In late winter, these anomalies are inverted and a negative phase of the Arctic Oscillation with a more wavy mean flow and a tendency towards stronger meridionalization is observed.

Item Type:	Article
Related URLs:
Keywords:	diabatic heating, heat advection, wave-mean flow interactions, North Atlantic Oscillation, Arctic Oscillation, sea ice, climate change, Arctic Amplification, polar-mid-latitude linkages
Subjects:	Natural Environment > Atmosphere Natural Environment > Cryosphere Natural Environment > Oceans
Organizations:	Unspecified
Date Deposited:	09 Nov 2023 10:41
URI:	http://library.arcticportal.org/id/eprint/2684

Actions (login required)

View Item