Ning et al. (2025) Atmospheric Freezing Level Height Changes

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: International Journal of Climatology
• Year: 2025
• Date: 2025-10-07
• Authors: Liang Ning, Raymond S. Bradley, Henry F. Díaz, Douglas R. Hardy, Chuanxi Xu
• DOI: 10.1002/joc.70133

Research Groups

[Not explicitly stated in the abstract]

Short Summary

This study updates global freezing level height (FLH) changes to 2023 using observations and models, revealing significant FLH increases, particularly in extra-tropical and high northern latitudes, which are linked to accelerated glacier mass loss driven by tropical sea surface temperature variability.

Objective

• To update global freezing level height (FLH) changes to 2023 using observations and model simulations.
• To investigate the spatial patterns and drivers of FLH variations globally.
• To assess the impact of observed FLH changes on glacier mass balance, particularly in Arctic and high mountain regions.

Study Configuration

• Spatial Scale: Global, with specific focus on Tropics, extra-Tropics, high latitudes in the Northern Hemisphere, Arctic, and high mountain stations.
• Temporal Scale: Historical analysis updated to 2023, including trends over "recent decades," and future projections for "last several decades of the 21st century."

Methodology and Data

• Models used: Unspecified climate models for simulations.
• Data sources: Observational data, glacier mass balance records, and data related to tropical sea surface temperature variability.

Main Results

• Global freezing level height (FLH) changes are updated to 2023, showing positive trends.
• Relatively smaller positive FLH trends and changes are observed over the Tropics.
• Higher FLH changes are found over the extra-Tropics, with maximum FLH rises occurring over high latitudes in the Northern Hemisphere.
• Temporal FLH variations are largely driven by the variability of tropical sea surface temperature.
• Observed FLH changes over Arctic and high mountain stations have led to significant glacier mass losses.
• Glacier mass losses have accelerated in recent decades.
• Model simulations project maximum increases in tropical middle to high troposphere temperature over the last several decades of the 21st century.

Contributions

• Provides an up-to-date assessment of global freezing level height changes to 2023.
• Offers a detailed spatial analysis of FLH trends, differentiating between tropical and extra-tropical regions and highlighting high northern latitude increases.
• Identifies tropical sea surface temperature variability as a primary driver for temporal FLH variations.
• Establishes a direct link between observed FLH changes and significant, accelerated glacier mass loss in critical cryospheric regions.
• Incorporates future projections of tropical tropospheric temperature increases, suggesting continued warming impacts.

Funding

[Not explicitly stated in the abstract]

Citation

@article{Ning2025Atmospheric,
  author = {Ning, Liang and Bradley, Raymond S. and Díaz, Henry F. and Hardy, Douglas R. and Xu, Chuanxi},
  title = {Atmospheric Freezing Level Height Changes},
  journal = {International Journal of Climatology},
  year = {2025},
  doi = {10.1002/joc.70133},
  url = {https://doi.org/10.1002/joc.70133}
}