Wednesday, 25 January 2012: 9:45 AM
Does Arctic Amplification Fuel Extreme Weather in Mid-Latitudes?
Room 354 (New Orleans Convention Center )
Recent studies suggest there may be a connection between Arctic Amplification – the enhanced warming in high northern latitudes relative to the northern hemisphere -- and the frequency and intensity of extreme weather events in mid-latitudes. Observational analyses and model experiments indicate that sea-ice loss during summer and earlier spring snow-melt on high-latitude land cause weaker poleward temperature gradients, which in turn affect the strength and wave amplitude of the polar jetstream during months following the surface changes. Higher-amplitude patterns typically change slowly and often lead to persistent weather conditions such as droughts, floods, heat waves, and cold spells. Evidence supporting the chain of events linking Arctic warming with mid-latitude conditions conducive to extreme weather will be presented.