资源环境科技发展态势分析平台

The emerging precursor in December Arctic oscillation (AO) for the following January temperature over East Asia (T-EA) has been noticed by recent researches. This study evaluates the precursor in December AO for the following January T-EA using 35 climate models from the Coupled Model Intercomparison Project Phase 5. Results indicate that, 24 (multi-model ensemble mean; MME-GOOD) out of total 35 models reproduce the statistically significant positive correlation between the December AO and the January T-EA identified in the observation, but the remaining 11 models (MME-BAD) fail. Further, the investigation focuses on these models' simulations for the December AO-associated atmospheric circulation in January. Eighteen (MME-GOOD-18) out of the above 24 models reproduce the persistence of December AO-related atmospheric circulation, including the seesaw structure of the sea level pressure anomalies, the sweeping southerly 850-hPa wind anomalies over the East Asia-Northwest Pacific region, the weakening of the East Asian trough, and the weakened meridional shear of the East Asian jet stream in January following an enhanced December AO. It is found that the propagation of stationary planetary waves plays a crucial role in connecting the December AO and the January T-EA. Therefore, the models' ability to simulate the stratosphere-troposphere interaction is essential for the successful simulations on the persistence of December AO. Additionally, the future projections indicate that the precursor in December AO for the following January T-EA is still robust during the 21st century.