Accelerated warming in the northern midlatitude summer since the 1990s
- PNNL, United States of America (haiyan.teng@pnnl.gov)
The northern midlatitude summer has experienced rapid warming since the 1990s, especially in Europe, Central Siberia-Mongolia, the West Coast of North America as well as several continental Arctic regions. These “hot spots” are connected by a chain of high-pressure ridges from an anomalous wavenumber-5 Rossby wave train in the upper troposphere. Here by cross-examining reanalysis datasets and a suite of Coupled Model Intercomparison Project Phase 6 (CMIP6) baseline experiments, we demonstrate that the anthropogenically forced response may be intertwined with internal multidecadal variability, making it difficult to partition the 1979-2020 trend with state-of-the-art climate models. Instead, we take a “storyline” approach with a planetary wave model and sensitivity experiments with an Earth system model to explore key underlying driving factors. Our results highlight the importance of multiscale interaction with synoptic eddy via atmosphere-ocean and atmosphere-land coupling in shaping the multidecadal regional warming trend which has enormous socioeconomic implications.
How to cite: Teng, H., Leung, R., Branstator, G., Lu, J., and Ding, Q.: Accelerated warming in the northern midlatitude summer since the 1990s, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6506, https://doi.org/10.5194/egusphere-egu21-6506, 2021.