Disentangling wave-like atmospheric trends in the northern hemisphere midlatitudes

Summertime trend analysis reveals that regions in the NH midlatitudes experience a marked set of changes in surface temperature, sea level pressure, and upper-atmosphere streamfunction. Among these changes are deeper Atlantic lows, extreme Western European temperatures, and stronger highs over Western Russia. As these regional signatures tend to lie outside the range of CMIP6 model simulations they might constitute a joined dynamic response that is missed by the models. Here, we examine to what degree the regional signatures cohere as one increasingly prevalent circumglobal wave, or to what degree they reflect distinct regional processes. For this we use both ERA-5 reanalysis data and a selection of CMIP6 climate model simulations. In the process, we try to better understand the mismatch between observations and climate models.