title: Facets of Arctic energy accumulation based on observations and reanalyses 2000-2015.
abstract: Various observation- and reanalysis-based estimates of sea ice mass and ocean heat content trends imply that the energy imbalance of the Arctic climate system was similar [1.0 (0.9,1.2) Wm-2] to the global ocean average during the 2000-2015 period. Most of this extra heat warmed the ocean, and a comparatively small fraction went into sea ice melt. Poleward energy transports and radiation contributed to this energy increase at varying strengths. On a seasonal scale, stronger radiative energy input during summer associated with the ice-albedo feedback enhances seasonal oceanic heat uptake and sea ice melt. In return, lower sea ice extent and higher sea surface temperatures lead to enhanced heat release from the ocean during fall. This weakens meridional temperature gradients, consequently reducing atmospheric energy transports into the polar cap. The seasonal cycle of the Arctic energy budget is thus amplified, whereas the Arctic's long-term energy imbalance is close to the global mean.
authors.affiliation: Department of Meteorology and Geophysics University of Vienna Vienna Austria; Austrian Polar Research Institute Vienna Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Mayer
authors.affiliation: Department of Meteorology and Geophysics University of Vienna Vienna Austria; Austrian Polar Research Institute Vienna Austria.
authors.forename: Leopold
authors.initials: L
authors.lastname: Haimberger
authors.affiliation: Department of Meteorology and Geophysics University of Vienna Vienna Austria; Austrian Polar Research Institute Vienna Austria.
authors.forename: Marianne
authors.initials: M
authors.lastname: Pietschnig
authors.affiliation: Centro Euro-Mediterraneo sui Cambiamenti Climatici Bologna Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Storto
keywords: Arctic; climate change; energy budget; ocean heat content; sea ice