Understanding the Role of Ocean Dynamics for Changes in the North Atlantic Storm Track

The North Atlantic storm track is important for the poleward transport of heat, momentum and moisture and significantly impacts the weather over Europe and North America. As such, it is of great interest to understand how the strength and position of the storm track will evolve under future climate change. In response to greenhouse gas forcing, the North Atlantic storm track is projected to experience a strengthening and eastward extension over the next century. Recent evidence suggests that the storm track may be influenced the Atlantic Meridional Overturning Circulation (AMOC) through its impact on the meridional sea surface temperature gradient and thus the surface baroclinicity. This study aims to examine how ocean forcing/coupling affects to the ability of CMIP models to simulate the behavior of the North Atlantic storm track. In particular, features of both the North Atlantic storm track and ocean heat transport are compared within the context of CMIP5, focusing on the relationships simulated from NorESM and CESM. A suite of sensitivity experiments will then be used to assess the extent to which ocean dynamics are responsible for the spread in the ocean-atmosphere coupling and the North Atlantic storm track responses.