Climatologies of Northern Hemisphere Pacific blocking and Atlantic blocking in relation to storm tracks are examined with a conventional atmospheric general circulation model (GCM) called AFES (with hydrostatic dynamical core and convection, radiation, gravity wave, turbulent-process, and land-process schemes) and a cloud-resolving atmospheric GCM called NICAM. The models are prescribed with realistic sea surface temperature, i.e., AMIP-type simulations, using 5 different horizontal resolutions ranging from 300-km to 25-km and two different convection schemes for AFES and using 2 different horizontal resolutions of 56-km and 28-km for NICAM. As such, a total of 12 experiments are conducted by combining each convection scheme and resolution, from January 1982 to December 2021. For detection of blocking, the potential vorticity anomaly-based method by Schwierz et al. (2004) with a 5-day duration threshold is utilized. It is found that the Pacific and Atlantic blocking frequencies and storm track intensities are adequately simulated with a horizontal resolution of 50-km or 100-km, which get increasingly overestimated with finer resolution in both winter and summer seasons. This overestimation of Pacific and Atlantic blocking frequencies is linked to increase in storm track intensities with resolution over both the Pacific and Atlantic.

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