Chu et al. (2025) Evaluation of Tropical Cyclone Characteristics in the SPEAR Large Ensemble Simulations

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

Identification

• Journal: Journal of Advances in Modeling Earth Systems
• Year: 2025
• Date: 2025-11-26
• Authors: Wenchao Chu, Jorge L. García‐Franco, Suzana J. Camargo, Chia‐Ying Lee, Michael K. Tippett, Hiroyuki Murakami
• DOI: 10.1029/2025ms005361

Research Groups

Geophysical Fluid Dynamics Laboratory (GFDL)

Short Summary

This study evaluates tropical cyclone (TC) activity in the SPEAR model, finding that it generally captures key TC characteristics and their modulation by natural climate variability, despite exhibiting regional biases in track density, landfall frequency, and precipitation.

Objective

• To evaluate the simulation of tropical cyclone (TC) activity, including track density, seasonality, landfall frequency, and precipitation, as well as its modulation by natural climate variability (El Niño-Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation) within the SPEAR model large ensemble simulations.

Study Configuration

• Spatial Scale: Global, with regional focus on Northwest Pacific, Northeast Pacific, North Atlantic, and other continental landmasses.
• Temporal Scale: Climatological (long-term average) and interannual to multidecadal (natural variability modes).

Methodology and Data

• Models used: Seamless System for Prediction and EArth System Research (SPEAR) model large ensemble simulations.
• Data sources: Model simulations, compared against observational data.

Main Results

• SPEAR generally captures key TC characteristics (track density, seasonality, landfall frequency, precipitation) but exhibits biases.
• TC track density is overestimated over the Northwest Pacific and underestimated over the Northeast Pacific.
• TC landfall frequency is underestimated across most continents.
• Tropical cyclone precipitation (TCP) bias is regionally variable, primarily driven by biases in TC occurrence rather than precipitation per TC, though inner-core TCP is overestimated.
• SPEAR reasonably simulates the observed temporal and spatial patterns of natural variability (ENSO, PDO, AMO) and their TC modulations.
• Specifically, SPEAR simulates increased TC activity over the Northwest Pacific and decreased activity over the North Atlantic during El Niño events.
• It captures increased TC activity over the tropical Pacific Ocean during the PDO positive phase and increased activity over the North Atlantic during the AMO positive phase.
• TCP anomalies associated with climate modes closely follow TC track density anomalies, mainly due to differences in TC occurrence.
• SPEAR reproduces TC landfall frequency anomalies for ENSO and AMO but shows an opposite signal for PDO-related anomalies compared to observations.

Contributions

• Comprehensive evaluation of tropical cyclone activity and its modulation by major climate modes within the SPEAR model.
• Detailed identification and quantification of regional biases in TC track density, landfall frequency, and precipitation.
• Attribution of tropical cyclone precipitation biases primarily to differences in TC occurrence.
• Assessment of SPEAR's capability to simulate observed TC responses to natural climate variability.

Funding

• Not specified in the abstract.

Citation

@article{Chu2025Evaluation,
  author = {Chu, Wenchao and García‐Franco, Jorge L. and Camargo, Suzana J. and Lee, Chia‐Ying and Tippett, Michael K. and Murakami, Hiroyuki},
  title = {Evaluation of Tropical Cyclone Characteristics in the SPEAR Large Ensemble Simulations},
  journal = {Journal of Advances in Modeling Earth Systems},
  year = {2025},
  doi = {10.1029/2025ms005361},
  url = {https://doi.org/10.1029/2025ms005361}
}