Evaluation of the Linkage Between the Variations in Jet Stream Shape and Surface Air Temperature From <scp>CMIP6</scp>

ABSTRACT Jet streams are key components of mid‐ to high‐latitude atmospheric circulation, strongly influencing global weather and climate through heat and momentum transport. Based on our previous work on jet stream shape variability and its climatic impacts, this study assesses the ability of CMIP6 models to simulate the relationship between jet stream shapes and surface air temperature (SAT), using both AMIP and historical runs. Based on weighted Taylor scores, interannual variability skill (IVS) scores and jet stream indices, AMIP simulations generally outperform historical runs in representing both jet streams and SAT. Most models capture SAT anomalies over East Asia and North America, underscoring a robust link between regional temperature extremes and distinct jet patterns. They also reproduce sea level pressure anomalies resembling the Arctic Oscillation (AO), suggesting that AO‐like circulation is a key driver of temperature extremes across jet groups. In addition, horizontal temperature advection anomalies closely match SAT anomalies, highlighting their role as a primary term in the thermodynamic equation shaping temperature distributions in critical regions.