Internal Climate Dynamics Underpin the Recent Decadal Reversal of Eurasian Summer Diurnal Temperature Range

A critical gap remains in identifying physical drivers of decadal Diurnal Temperature Range (DTR) changes over Eurasia. Here, we detect a distinct summertime DTR reversal over Eurasia around the 1990s by a novel energy diagnosis methodology based on observations and MPI-ESM large-ensemble simulations. This reversal is primarily driven by decadal changes in net shortwave radiation and surface turbulence fluxes, linked to an accelerated decline in cloud cover and intensified cloud-radiative effects. Furthermore, this reversal pattern emerges from the superposition of spatially coherent and heterogeneous components. The former is largely attributable to external forcings, while the latter is amplified by internal dynamics. This heterogeneous structure exhibits pronounced strong–weak–strong anomalies stretching from Europe to mid‑latitude East Asia. It is driven by high‑altitude wave activities with a circumglobal teleconnection triggered by a tripolar North Atlantic sea surface temperature pattern.