Arctic Sea Ice Reduction and Extreme Climate Events over the Mediterranean Region

Abstract During the last decade, Arctic sea ice cover has experienced an accelerated decline that has been suggested to drive the increased occurrence of extremely cold winter events over continental Europe. Observations and modeling studies seem to support the idea that Mediterranean climate is als...

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Bibliographic Details
Published in:Journal of Climate
Main Authors: Gianluca Redaelli, Barbara Grassi, Guido Visconti
Format: Article in Journal/Newspaper
Language:English
Published: 2013
Subjects:
Online Access:https://www.openaccessrepository.it/record/106981
https://doi.org/10.1175/jcli-d-12-00697.1
Description
Summary:Abstract During the last decade, Arctic sea ice cover has experienced an accelerated decline that has been suggested to drive the increased occurrence of extremely cold winter events over continental Europe. Observations and modeling studies seem to support the idea that Mediterranean climate is also changing. In this work, the authors estimate potential effects on the Mediterranean Basin, during the winter period, of Arctic sea ice reduction. Two sets of simulations have been performed by prescribing different values of sea ice concentrations (50% and 20%) on the Barents–Kara Seas in the NCAR Community Atmosphere Model, version 3 (CAM3), as representative of idealized present and future sea ice conditions. Global model simulations have then been used to run the Abdus Salam International Centre for Theoretical Physics (ICTP) Regional Climate Model, version 4 (RegCM4), over central Europe and the Mediterranean domain. Simulations provide evidence for a large-scale atmospheric circulation response to sea ice reduction, resembling the negative phase of the Arctic Oscillation (AO) and characterized by a wave activity flux from the North Atlantic toward the Mediterranean Basin, during winter months. An increase in the occurrence and intensity of extreme cold events, over continental Europe, and extreme precipitation events, over the entire Mediterranean Basin, was found. In particular, simulations suggest an increased risk of winter flooding in southern Italy, Greece, and the Iberian Peninsula.