Zhou et al. (2025) Shortened intensification duration offsets the increase of tropical cyclone lifetime maximum intensity

Identification

• Journal: npj Climate and Atmospheric Science
• Year: 2025
• Date: 2025-12-24
• Authors: Yufeng Zhou, Yanluan Lin
• DOI: 10.1038/s41612-025-01295-3

Research Groups

• Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, China

Short Summary

This study introduces a rate-duration framework to decompose tropical cyclone (TC) lifetime maximum intensity (LMI), revealing that a significant shortening of intensification duration, driven by poleward and landward shifts in TC genesis locations, has offset nearly half (48.7%) of the increase in strong TCs despite rising intensification rates in recent decades.

Objective

• To introduce a rate-duration framework to decompose tropical cyclone (TC) lifetime maximum intensity (LMI) and quantitatively attribute the competing roles of intensification rate versus duration in shaping LMI and its response to warming.

Study Configuration

• Spatial Scale: Global, with analysis across all TC basins (Western Pacific, Northern Atlantic, Eastern Pacific, Southern Pacific, Northern Indian Ocean, and Southern Indian Ocean). TC genesis locations (latitude, distance to land) are a key focus.
• Temporal Scale:
  • Observational period: 1982-2023 (42 years).
  • Historical period for counterfactual analysis: 1982-2002.
  • Recent period for counterfactual analysis: 2003-2023.
  • Model projections: 1980-1999 (control) and 2030-2049 (warming).

Methodology and Data

• Models used:
  • CMIP6 HighResMIP (High Resolution Model Intercomparison Project) for future projections under the SSP5-8.5 scenario.
  • GFDL AM4 (Atmospheric Model version 4) for idealized warming experiments with uniform +4 K warming.
• Data sources:
  • Tropical Cyclone observations: International Best Track Archive for Climate Stewardship (IBTrACS v04r00).
  • Sea Surface Temperature (SST): Optimum Interpolation Sea Surface Temperature (OISST) based on AVHRR-only datasets (0.25° resolution).
  • Vertical Wind Shear (VWS): ERA5 (fifth-generation reanalysis of the European Centre for Medium-Range Weather Forecasts).

Main Results

• The bimodal distribution of TC LMI has amplified from 1982-2023, with two distinct peaks around 25.7 m/s (50 kt) and 61.7 m/s (120 kt). Strong TCs intensified at +0.93 m/s per decade (+1.8 kt per decade), while weak TCs weakened at -0.46 m/s per decade (-0.9 kt per decade).
• Global intensification duration of TCs has significantly shortened by 1.4 hours (3.4%) per decade during 1982-2023.
• This shortening is primarily linked to concurrent poleward (0.25° per decade) and landward (40.0 km per decade) shifts in TC genesis locations.
• The shortened intensification duration suppresses TC intensification, offsetting approximately 48.7% of the increase in strong TCs driven by enhanced intensification rates.
• Each 1° increase in genesis latitude corresponds to an average reduction in intensification duration of 1.61 hours, while each 100 km decrease in distance from land at genesis shortens this window by approximately 1.79 hours.
• High-resolution climate models (CMIP6 HighResMIP, GFDL AM4) project a consistent shortening of TC intensification duration under warming, with an average reduction of 2.3% (1.7 hours), which offsets approximately 35% of the warming-induced increase in the mean LMI.

Contributions

• Introduction of a novel "rate-duration framework" that decomposes TC LMI into intensification rate and duration, offering a new fundamental perspective on LMI evolution.
• Quantitative attribution of the competing roles of intensification rate and duration in shaping LMI and its response to warming, highlighting the previously overlooked importance of timescale constraints.
• Demonstration that the observed shortening of intensification duration, linked to shifts in TC genesis locations, acts as a significant self-regulating mechanism that partially offsets the increase of intense storms under warming.
• Robust findings supported by both extensive global observational data (1982-2023) and high-resolution climate model simulations, enhancing the reliability and generalizability of the conclusions.

Funding

• National Natural Science Foundation of China (42130603)

Citation

@article{Zhou2025Shortened,
  author = {Zhou, Yufeng and Lin, Yanluan},
  title = {Shortened intensification duration offsets the increase of tropical cyclone lifetime maximum intensity},
  journal = {npj Climate and Atmospheric Science},
  year = {2025},
  doi = {10.1038/s41612-025-01295-3},
  url = {https://doi.org/10.1038/s41612-025-01295-3}
}