Investigation and Modeling of D-Region Responses to X-Class Solar Flares During the Ascending Phase of Solar Cycle 25 Using VLF and GOES X-Ray Observations

Dataset Title Investigation and Modeling of D-Region Responses to X-Class Solar Flares During the Ascending Phase of Solar Cycle 25 Using VLF and GOES X-Ray Observations Description This dataset contains Very Low Frequency (VLF) amplitude observations, GOES X-ray flux data, FISM solar irradiance data, and LWPC simulation outputs used to investigate D-region ionospheric responses to X-class solar flares during the ascending phase of Solar Cycle 25. The dataset also includes MATLAB scripts used for data processing, analysis, and modeling. The materials provided enable full reproducibility of the results presented in the associated manuscript submitted to the Journal of Geophysical Research: Space Physics. Folder Structure The dataset is organized into the following directories: data_vlf_raw/ – Raw high-resolution VLF amplitude recordings data_vlf_processed/ – Processed per-minute VLF amplitude time series used in this study data_flux/ – GOES X-ray flux data data_fism/ – Solar irradiance data from the FISM model data_lwpc/ – LWPC simulation outputs scripts/ – MATLAB scripts for data processing, analysis, and modeling metadata/ – Documentation describing dataset variables and event catalogs File Description Raw VLF amplitude data are stored in files such as AL240601000000TBB_100A.mat, representing individual high-resolution recordings. Processed monthly files (e.g., TBB00_2405.mat) contain continuous per-minute VLF amplitude time series for an entire month, stored as a single vector. These processed datasets form the primary data used in the analysis presented in this study. Naming Convention Processed VLF files follow the naming format:TBB00_2405.mat, where: TBB – transmitter identifier 00 – north–south (NS) propagation channel 24 – year (2024) 05 – month (May) .mat – MATLAB file format All amplitude values are expressed in decibels (dB), and timestamps are provided in Coordinated Universal Time (UTC). Reproducibility To reproduce the main results, users should execute the primary MATLAB script located in the scripts/ directory (e.g., main_analysis.m). The scripts are designed to operate on the processed datasets provided in this repository.