Response of intense North Atlantic midlatitude cyclones to a warmer
climate in the GFDL X-SHiELD global storm-resolving kilometer-scale
model
Abstract
Leveraging the novel kilometer-scale global storm-resolving model GFDL
X-SHiELD, we investigate the impact of a 4 K increase in sea surface
temperatures on Northern Hemisphere midlatitude cyclones, over a
three-year-long period. X-SHiELD simulations show a poleward shift in
midlatitude cyclone tracks under +4 K warming, consistent with CMIP
model projections. Thanks to X-SHiELD’s high resolution and explicit
deep convection, we provide a detailed analysis of the warm and cold
sectors of midlatitude cyclones, which are typically underrepresented in
coarser CMIP models. Compositing the 100 most intense midlatitude
cyclones in the North Atlantic, we find that the warm sector exhibits
wind speed and precipitation increases of up to 15% and 20% per degree
of warming, respectively, while changes in the cold sector are less
pronounced. This study demonstrates X-SHiELD’s potential to provide a
realistic-looking picture into the evolving risks posed by midlatitude
cyclones in a warmer world.