Contains wave observations by free-drifting Spotter buoys from targeted aerial deployments into Hurricane Ian (2022) and opportunistic measurements from the free-drifting Sofar Ocean Spotter global network in Hurricane Fiona (2022). The observations are co-located with modeled surface wind speeds from the U.S. Naval Research Laboratorys Coupled Ocean-Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS-TC). The data are used in the article to show the saturation of mean square slope at extreme wind speeds and the coincident transition from an equilibrium-dominated spectral tail to a saturation-dominated tail. This archive contains two main, table-like datasets of wind-wave data (from Ian and Fiona) and three derived datasets necessary to reproduce the results and figures in the article.

Description of the data and file structure

The dataset is organized into five files:

• ian_spotter_coamps_data.json - the main dataset from Hurricane Ian (2022) containing hourly records of surface wave statistics in the form of scalar energy spectra, directional moments, and derived products (including mean square slope) with co-located modeled surface wind speeds from COAMPS-TC. The data can be sorted by Spotter id (using the spotter_id variable) to observe individual drift tracks as a function of time, or can be taken in aggregate to study bulk trends as a function of wind speed, etc. (as is done in the article with mean square slope versus wind speed).
• fiona_spotter_coamps_data.json - same as above, but for Hurricane Fiona (2022).
• binned_mss_data.csv - data to reproduce the binned mean square slopes and model wind speeds presented in the article.
• wave_spectra_binned_by_wind_speed_data.json - mean energy density data, binned by wind speed, to reproduce the mean energy density versus wind speed plot in the article. This data is derived from ian_spotter_coamps_data.json and fiona_spotter_coamps_data.json by binning and averaging the energy_density in 10 m/s bins using COAMPS_10m_wind_speed.
• wave_spectra_binned_by_wave_age_data.json - mean energy density data, binned by mean period wave age, to reproduce the mean energy density versus wave age plot in the article. This data is derived from ian_spotter_coamps_data.json and fiona_spotter_coamps_data.json by binning and averaging the energy_density using mean_wave_age.

Variable descriptions are provided in dataset_description.pdf.

Sharing/Access information

Data was derived from the following sources:

• Spotter buoys are a product of Sofar Ocean (San Francisco, CA). Data are accessible at https://spotter.sofarocean.com.
• COAMPS-TC is developed and operated by the U.S. Naval Research Laboratory, Monterey Marine Meteorology Division. More information can be found at https://www.nrlmry.navy.mil/coamps-web/web/home.

This is the only publicly accessible location of this dataset.

Code/Software

The datasets are stored as text-based JSON and CSV files which can be read without the use of special software. The JSON files are created using the Python Pandas package DataFrame.to_json method with orient='records'. Example usage in Python and MATLAB are provided in example.py and example.m.