DOI: 10.5281/zenodo.18253197
title: A Global ERA5-based Tropical Cyclone Wind Field Dataset Enhanced by Integrated Parametric Correction Methods

description: Existing reanalysis datasets, such as ERA5, typically underestimate peak wind speeds and inadequately capture inner-core structural characteristics of TCs. To address these limitations, we introduce a globally applicable, high-resolution TC wind field dataset reconstructed from ERA5 through an integrated parametric correction approach. This novel methodology combines the Willoughby adjustment for open-ocean TCs, proportional correction methods for landfalling TCs, and a linear interpolation method to ensure smooth transitions in coastal regions.

How to use the dataset

Step 1. Identify the TC track in IBTrACS

Users should first locate the tropical cyclone of interest in the IBTrACS dataset (e.g., IBTrACS.ALL.v04r00.nc), using standard identifiers such as sid or usa_atcf_id. These identifiers uniquely define each TC track in the IBTrACS archive.

It is important to note that the TC identifiers used in TC_snapshot.zip are custom-defined identifiers introduced in this dataset, rather than the original IBTrACS identifiers.

To establish the correspondence, users should refer to the file Typhoon_news_string.nc, which provides a mapping between the IBTrACS identifiers (e.g., sid, usa_atcf_id) and the custom TC identifier (rank_number) used in this dataset. This rank_number serves as the link between IBTrACS and the snapshot files provided here.

Step 2. Locate the corresponding snapshot file

Within TC_snapshot.zip, each NetCDF file is named according to the custom TC identifier (rank_number). After identifying the appropriate rank_number using Typhoon_news_string.nc, users can locate the corresponding snapshot file in the archive.

Each snapshot file contains reconstructed TC wind field snapshots at multiple timestamps, together with the associated TC center position and structural parameters.

Step 3. Match time and location with ERA5

For a given analysis or forecast time, users should extract the snapshot whose timestamp matches the target ERA5 time. All wind fields are provided in latitude–longitude coordinates and are spatially aligned with ERA5.

Step 4. Replace the ERA5 TC core region

The ERA5 wind fields within the snapshot’s spatial domain can be directly replaced with the reconstructed TC wind fields provided in this dataset. No additional scaling is applied; the values represent the corrected TC wind speed structure derived from the parametric model.

Step 5. Retain ERA5 winds outside the TC influence zone

Only the TC-affected region should be replaced. ERA5 winds outside the snapshot domain should remain unchanged to preserve the large-scale synoptic consistency of the background flow.

Step 6. Optional post-processing

If required by a specific application or numerical model, users may apply additional smoothing or spatial interpolation to achieve the desired grid resolution. No further correction or intensity adjustment is necessary.

This workflow enables users to seamlessly integrate physically consistent, intensity‐corrected TC wind fields into their numerical models or observational analyses while maintaining compatibility with the original ERA5 dataset.

Limitations for High-Intensity Tropical Cyclones

For high-intensity tropical cyclones, the radius of maximum wind (RMW) is often much smaller than 25 km, which is comparable to the native spatial resolution of ERA5. As a result, the inner-core wind structure of these storms is insufficiently resolved in the original reanalysis fields. Under such conditions, the effectiveness of the wind-field correction method applied in this dataset is reduced, particularly for the strongest systems.

Users should be aware that this limitation originates from the intrinsic resolution constraint of ERA5 rather than from the correction framework itself.

Recommended Workflow for Strong Tropical Cyclones

When analyzing strong tropical cyclones whose radius of maximum wind is significantly smaller than the ERA5 grid spacing (~25 km), we recommend an enhanced two-step workflow. First, the original ERA5 wind fields associated with these events should be interpolated to a higher spatial resolution using robust and physically consistent interpolation methods. Subsequently, the wind-speed correction scheme described in our study (https://doi.org/10.1038/s41597-025-05789-w) can be applied to the interpolated fields.

This procedure helps to better represent the compact inner-core wind structure of intense tropical cyclones and can substantially improve the practical usability of the corrected wind data.