Changing Northern Hemisphere Storm Tracks in an Ensemble of IPCC Climate Change Simulations

Abstract

Winter storm-track activity over the Northern Hemisphere and its changes in a greenhouse gas scenario (the Special Report on Emission Scenarios A1B forcing) are computed from an ensemble of 23 single runs from 16 coupled global climate models (CGCMs). All models reproduce the general structures of the observed climatological storm-track pattern under present-day forcing conditions. Ensemble mean changes resulting from anthropogenic forcing include an increase of baroclinic wave activity over the eastern North Atlantic, amounting to 5%–8% by the end of the twenty-first century. Enhanced activity is also found over the Asian continent and over the North Pacific near the Aleutian Islands. At high latitudes and over parts of the subtropics, activity is reduced. Variations of the individual models around the ensemble average signal are not small, with a median of the pattern correlation near r = 0.5. There is, however, no evidence for a link between deviations in present-day climatology and deviations with respect to climate change.

Midlatitude atmospheric circulation responses under 1.5 °C and 2.0 °C warming and implications for regional impacts

“…The storm track responses are also small, but broadly consistent with previous results from CMIP3 and CMIP5 (e.g., Ulbrich et al, 2008;Chang et al, 2012;Zappa et al, 2013).…”

Understanding the varied response of the extratropical storm tracks to climate change

“…The MAPE scaling also provides insight into the intermodel scatter in changes in storm-track intensity. Such intermodel scatter has likely contributed to the somewhat divergent conclusions of past studies, in tandem with the use of different measures which focus on different physical aspects of the storm tracks (25). The varying magnitudes of changes in EKE in different models are captured by the scaling with nonconvective MAPE in JJA (Fig.…”

Sensitivity of historical orographically enhanced extreme precipitation events to idealized temperature perturbations

“…However, the climate model trajectories of storm tracks are highly variable for different ensemble members (Bengtsson et al 2006;Ulbrich et al 2008;Laîné et al 2009), and knowing which one will represent reality in the future is difficult. Climate models do however agree on a warmer and moister climate for mid and high latitudes (Collins et al 2013).…”