Investigating the atmospheric response to future sea ice loss in the western Arctic using a fully coupled global climate model

Thursday, 18 December 2014
Melissa Gervais, Bruno Tremblay, John R Gyakum and Eyad Atallah, McGill University, Montreal, QC, Canada
Sea ice in the Arctic is experiencing declines that are projected to result in a purely seasonal ice cover regime in the 22nd century. In regions of sea ice loss, this will lead to a local changes in the sensible and latent heat flux from the ocean to the atmosphere. Subsequent impacts on mid-latitude weather and climate may occur, for example through changes in air mass generation and properties, mass fields, and jet stream dynamics. The goal of this research is to examine the remote influences of sea ice loss on the atmosphere, with particular focus on loss in the western Arctic. Many studies have been conducted using atmospheric component models forced with specified (reduced) sea ice concentration and sea surface temperatures. These studies have the advantage of clearly separating the signal of sea ice loss from other changes in the climate system, however the experimental configuration neglects the inclusion of atmosphere-ocean feedbacks. The approach used in this study is to employ simulations of future climate using a fully coupled global climate model (GCM) from the Climate Model Intercomparison Project 5 (CMIP5) and applies a self organizing maps technique to identify spatial and temporal patterns in air masses, mass fields and sea ice concentration. Relationships between the atmospheric self organizing map patterns and sea ice concentrations in the model are used to identify dynamical links between sea ice loss and atmospheric variability in the context of a fully coupled model. Causes of inter-annual variability in western Arctic winter sea ice are investigated, as they pertain to a potential mechanism for predictability of this atmosphere-ocean-sea ice interaction and it's impacts over North America.