Feb 20, 2015

North Atlantic Storm-Track Sensitivity to Warming Increases with Model Resolution

by
Jeff Willison, Walter A. Robinson, and Gary M. Lackmann
,
American Meteorological Society
  • States that mesoscale condensational heating can increase the sensitivity of modeled extratropical cyclogenesis to horizontal resolution
  • Presents a pseudo global warming experiment to investigate how this heating-enhanced sensitivity to resolution changes in a warmer and thus moister atmosphere
  • Uses the Weather Research and Forecasting (WRF) Model with 120- and 20-km grid spacing to simulate current and future climates
  • Finds that the North Atlantic storm-track response to global warming is amplified at the higher model resolution
  • Finds the most dramatic changes occur over the northeastern Atlantic, where resolution typical of current general circulation models (GCMs) results in a smaller global warming response in comparison with that in the 20-km simulations
  • Results suggest that caution is warranted when interpreting projections from coarse-resolution GCMs of future cyclone activity over the northeastern Atlantic