Atmospheric winter response to Arctic sea ice changes in reanalysis data and model simulations. Issue 13 (4th July 2016)

• Record Type: Journal Article
• Authors: Jaiser, Ralf; Nakamura, Tetsu; Handorf, Dörthe; Dethloff, Klaus; Ukita, Jinro; Yamazaki, Koji
• Is Part Of: Journal of geophysical research. Volume 121:Issue 13(2016)
• Page Start: 7564
• Page End: 7577
• Publication Date: 2016-07-04
• Subjects: polar midlatitude linkages -- stratosphere‐troposphere coupling -- planetary wave activity -- Arctic amplification -- polar vortex; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2015JD024679
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The changes of atmospheric flow patterns related to Arctic Amplification have impacts well beyond the Arctic regional weather and climate system. Here we examine modulations of vertically propagating planetary waves, a major feature of the climate response to Arctic sea ice reduction by comparing the corresponding results of an atmospheric general circulation model with reanalysis data for periods of high and low sea ice conditions. Under low sea ice condition we find enhanced coupling between troposphere and stratosphere starting in November with preferred polar stratospheric vortex breakdowns in February, which then feeds back to the troposphere. The model experiment and ERA‐Interim reanalysis data agree well with respect to temporal and spatial characteristics associated with vertical planetary wave propagation including its precursors. The upward propagating planetary wave anomalies resemble a wave number 1 and 2 pattern depending on region and timing. Since our experimental design only allows influences from sea ice changes and there is a high degree of resemblance between model results and observations, we conclude that sea ice is a main driver of observed winter circulation changes. Key Points: Simulation of Arctic sea ice impact shows high resemblance to observed stratosphere‐troposphere coupling in time and space Significant connection with the stratosphere first appears in Barents and Kara Sea region and subsequently in Pacific region Stratospheric response to sea ice changes is robust regardless of decadal‐scale variations of SSW occurrence