The extratropical storm tracks play a major role in shaping the midlatitude climate through important contributions to the atmospheric heat transport between tropical and polar regions and its associated effects on energy balances. In response to changes in the climate from anthropogenic forcing, the location and intensity of the storm tracks are projected to change, with the North Atlantic storm track projected to shift poleward, affecting the weather and climate of western Europe. The poleward shift of the North Atlantic storm track arises from competing effects on the region’s meridional temperature gradient. Arctic Amplification weakens the climatological gradients, hence weakening the storm track, while on the other hand, low latitude warming has the opposite effect by strengthening the climatological gradient. In this talk, I will focus on the role of Arctic Amplification induced by sea ice loss on the midlatitude heat transport. Using a hierarchy of ocean-atmosphere coupling complexity, I describe the role of air-sea interactions on the extratropical storm tracks in the northern hemisphere. Through this analysis of the model hierarchy, the roles of ocean dynamics and interactive surface heat fluxes on the location and intensity of the storm tracks are unveiled. We find that ocean dynamics modulate the location of the storm track changes while interactive heat fluxes control the intensity of the signal. Further, in addition to presenting the roles of the different components of ocean-atmosphere coupling, we expose the mechanisms behind changes in atmospheric heat transport that arise from sea ice loss and ocean-atmosphere interaction.
Physical Mechanisms Behind the Midlatitude Atmospheric Energy Transport Response to Imposed Arctic Sea Ice Loss
Host: Ramina Alwarda