Northern Hemisphere winter midlatitude atmospheric variability in CMIP5 models

The Northern Hemisphere midlatitude winter atmospheric variability simulated by Coupled Model Intercomparison Project phase 5 (CMIP5) models is analyzed at spatial and temporal scales corresponding to the growth of baroclinic eddies and planetary waves. We use a global scalar metric of the wave energy frequency-wave number spectrum to identify potential improvements of the CMIP5 ensemble compared to previous coordinated model simulations (CMIP3). We also evaluate whether CMIP5 models predict future shifts in the global baroclinic eddies and planetary-scale wave activities. With respect to CMIP3, no significant improvements are found, thereby suggesting that no significant breakthrough in the modeling of the climate system has been hit over the last few years. No significant changes are found in RCP4.5 scenarios for the selected metric of the baroclinic and planetary-scale atmospheric flows, thus indicating that localized changes with potential societal impact might not be related to changes in key fundamental properties of the atmospheric circulation. Key Points Performance of CMIP5 in describing global statistics of the atmosphere Biases larger than 20% in most cases No change in the statistics of the baroclinic and planetary scale motions ©2014. American Geophysical Union. All Rights Reserved.