Changes in resolution sensitivity under global warming

We have previously shown that the intensity of individual extratropical cyclones and their aggregate behavior in the North Atlantic stormtrack are strongly sensitive to horizontal resolution. Current GCM resolutions are inadequate for representing mesoscale condensation heating, which plays an important role in cyclogenesis. Here we investigate the upscale effect of this GCM deficiency on the large-scale flow. We use the Weather Research and Forecast (WRF) model configured globally with a high-resolution 2-way nest in the Northern Hemisphere mid-latitudes. Multiple years are simulated with and without the nest. Differences in cyclone dynamics develop as mesoscale latent heating is better resolved and the climatological stormtracks respond. We also show the response of terms in the Lorenz energy cycle. Our results allow for better understanding of potential biases in projections of stormtrack behavior and the role of extratropical cyclones in the general circulation under global warming.