Transcript Slide 1
Arctic Climate Change John C. Fyfe Canadian Centre for Climate Modelling and Analysis Questions 1. What is the scientific basis for Arctic amplification? 2. Is there a human influence on Arctic climate change? 3. How accurate are model projections of Arctic climate change? Temperature anomaly (°C) Winter temperatures over land Arctic Northern Hemisphere Year Graversen et al. [2008] Linked to heat transport °C per decade (vertically weighted) Annual trends 1991 to 2000 Yang, Fyfe and Flato [2010] Level (hPa) Linked to heat transport Level (hPa) °C per decade (vertically weighted) Annual trends 1991 to 2000 Latitude Yang, Fyfe and Flato [2010] Winter temperature trends: 1989 to 2008 Linked to sea ice Level (hPa) Total trends Screen and Simmonds [2010] Summer moisture trends: 1989 to 2008 Linked to sea ice Level (hPa) Total trends Screen and Simmonds [2010] The Antarctic paradox: it’s sea ice is increasing Model sea ice change: 1979-2005 The ozone hole is linked to less, not more, sea ice! Sigmond and Fyfe [2010] A human influence on Arctic warming Temperature anomaly (°C) OBS ALL NAT Year Gillett et al. [2008] A human influence on Arctic moistening OBS ANT ALL NAT Min et al. [2008] Arctic surface temperature projections IPCC AR4 WG1 Report [2007] Arctic sea ice extent projections Boé and Hall [2009] April sea ice thickness (meters) From observed winds From model winds Bitz, Fyfe and Flato [2002] Contaminant pathways Macdonald, Harner and Fyfe [2005] A typical global climate model grid IPCC AR4 WG1 Report [2007] Jakobshavn Glacier Acceleration triggered by the arrival of warm ocean waters @Konrad Steffen Holland et al. [2008] Main messages 1. While our understanding of Arctic climate change is advancing some significant challenges remain 2. While climate models for the Arctic are continuing to improve some important shortcomings remain Arctic Climate Change John C. Fyfe Canadian Centre for Climate Modelling and Analysis