Xie et al. (2025) Changing Northern Hemisphere weather linked to warming amplification in High Mountain Asia

Identification

• Journal: Communications Earth & Environment
• Year: 2025
• Date: 2025-11-19
• Authors: Yongkun Xie, Jianping Huang, Guoxiong Wu, Jiaqin Mi, Yimin Liu, Zifan Su, Yuzhi Liu, Xiaodan Guan
• DOI: 10.1038/s43247-025-02883-0

Research Groups

• Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou, China
• National Key Laboratory of Earth System Numerical Modeling and Application, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
• College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
• College of Atmospheric Sciences, Lanzhou University, Lanzhou, China
• Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences & Shanghai Key Laboratory of Ocean-land-atmosphere Boundary Dynamics and Climate Change, Fudan University, Shanghai, China

Short Summary

Amplified warming in High Mountain Asia (HMA) has significantly altered Northern Hemisphere synoptic temperature variability (STV) from 1940–2022, enhancing summer STV in Canada and Russia while reducing winter STV in Eastern Europe and the Nordic Seas. These changes are primarily driven by modified high-frequency temperature advection through hemispheric teleconnections.

Objective

• To investigate and quantify the influence of amplified High Mountain Asia (HMA) warming on observed changes in synoptic temperature variability (STV) across the broader Northern Hemisphere.

Study Configuration

• Spatial Scale: Northern Hemisphere, with a focus on High Mountain Asia (regions with elevations greater than 500 meters), Canada, Russia, Eastern Europe, and the Nordic Seas.
• Temporal Scale: 1940–2022 for observational analysis; 1850–2014 for historical model simulations; 2000–2014 for three-hourly model sensitivity experiments.

Methodology and Data

• Models used: Community Earth System Model (CESM), version 2.1.3 (fully coupled, 0.9° × 1.25° finite volume grid). Experiments included a historical run (HIST) and a sensitivity run (HMA-sh0.5) where sensible heat flux over HMA was halved.
• Data sources:
  • European Centre for Medium-Range Weather Forecasting (ECMWF) reanalysis, version 5 (ERA5) for three-hourly and monthly near-surface air temperature, zonal and meridional wind velocity, vertical velocity, and surface pressure (1° × 1° and 2° × 2° grids).
  • Global Precipitation Climatology Project (GPCP) version 2.3 for precipitation data (2.5° × 2.5° grid).
  • NOAA Northern Hemisphere snow cover extent climate data record (88 × 88 cell polar stereographic grid).

Main Results

• Amplified HMA warming contributed to a significant increase in summer synoptic temperature variability (STV) in northern Russia (21% of observed regional trend) and southeastern Canada (34% of observed regional trend) during 1940–2022.
• HMA warming also led to a significant reduction in winter STV in northeastern Eastern Europe (21% of observed regional trend) and across the Nordic Seas (19% of observed regional trend) during the same period.
• These STV changes are primarily driven by modifications in synoptic horizontal temperature advection.
• HMA warming strengthens horizontal temperature gradients in Canada and Russia in summer, and weakens them in the Nordic Seas and Eastern Europe in winter.
• In winter Eastern Europe, reduced eddy kinetic energy (EKE) due to diminished baroclinic instability (negative Eady growth rate changes) also contributes to decreased STV.
• Hemispheric teleconnections, including changes in jet streams, Rossby waves, and air-sea interactions (North Pacific and Arctic Oceans), mediate these remote impacts by redistributing temperature and modulating atmospheric circulation stability.

Contributions

• Provides the first quantitative assessment of the far-reaching impacts of amplified HMA warming on Northern Hemisphere synoptic temperature variability (STV) in remote regions.
• Identifies the dominant physical processes (horizontal temperature advection, horizontal temperature gradients, eddy kinetic energy, baroclinic instability) and their seasonal variations driving these remote STV changes.
• Elucidates the distinct seasonal teleconnection mechanisms (jet stream changes, Rossby wave propagation, and air-sea interactions) that link HMA warming to remote weather variability.
• Highlights the critical need to consider HMA warming as a significant factor when investigating and predicting weather patterns in remote Northern Hemisphere regions.

Funding

• National Key R&D Program of China (2023YFF0806700)
• Fundamental Research Funds for the Central Universities (lzujbky-2025-jdzx01)

Citation

@article{Xie2025Changing,
  author = {Xie, Yongkun and Huang, Jianping and Wu, Guoxiong and Mi, Jiaqin and Liu, Yimin and Su, Zifan and Liu, Yuzhi and Guan, Xiaodan},
  title = {Changing Northern Hemisphere weather linked to warming amplification in High Mountain Asia},
  journal = {Communications Earth & Environment},
  year = {2025},
  doi = {10.1038/s43247-025-02883-0},
  url = {https://doi.org/10.1038/s43247-025-02883-0}
}