DOI: 10.5281/zenodo.15613860
title: Hinode/EIS Solar Flare Footpoint Non-Thermal Velocity Dataset (2011–2024)

description: EIS Flare Catalog and Non-thermal Velocity (NTV) Curves Data

This dataset contains non-thermal velocity (NTV) measurements from Hinode/EIS spectral lines during solar flares, organized by flare class and spectral line. It also includes a comprehensive flare catalog linking EIS observations to GOES flare events.

Files:



eis_flare_catalog_zenodo_release.csv - EIS flare catalog

ntv_curves_normalized_for_zenodo.csv - Normalized NTV curves

ntv_curves_raw_for_zenodo.csv - Raw (non-normalized) NTV curves


Flare Catalog Structure (eis_flare_catalog_zenodo_release.csv)

Each row corresponds to an EIS raster or exposure associated with a GOES flare. The catalog includes:

Flare Timing and Classification:



flare_peak, flare_start, flare_end, peak_time – Flare timing (GOES event list)

subtracted_goes_class, recalibrated_goes_class, uncalibrated_goes_class – Flare classification based on different calibration schemes

granular_flare_category – Simplified flare category (C1, C2–3, C>4, M, X)


Flare Positioning:



flare_hpcx, flare_hpcy – Helioprojective flare coordinates (arcsec)

flare_hpcx_pixel, flare_hpcy_pixel – Flare location in EIS pixel coordinates


EIS Observation Metadata:



study_id_x – EIS study identifier

eis_start_time_x, scan_time_x, column_time – EIS raster timing

time_offset_seconds – Time offset between EIS observation and flare peak

duration_from_peak – Observation duration relative to flare peak

eis_xcen, eis_ycen – Raster center in arcsec

eis_fovx, eis_fovy – Raster field-of-view dimensions (arcsec)


NTV Data Structure:

Each NTV CSV file contains the following columns:

Time and Identification:



bin_center: Time relative to flare peak (seconds)

spectral_line: Name of the spectral line (e.g., 'fe_12_195.12_ntv')

flare_class: Flare category ('C1', 'C2-3', 'C>4', 'M_class', 'X_class')

flare_category: Same as flare_class (for normalized data)


Statistical Measures (Raw Values):



mean: Mean NTV value in the time bin (km/s)

median: Median NTV value in the time bin (km/s)

std: Standard deviation of NTV values in the time bin (km/s)

percentile_25: 25th percentile (Q1) of NTV values (km/s)

percentile_75: 75th percentile (Q3) of NTV values (km/s)


Sample Information:



count: Number of individual measurements in the time bin

unique_flares: Number of unique flares contributing to the time bin


Normalized Values (only in normalized file):



norm_mean: Mean NTV normalized by peak value

norm_median: Median NTV normalized by peak value

norm_p25: 25th percentile normalized by peak value

norm_p75: 75th percentile normalized by peak value

normalization_factor: The peak value used for normalization (km/s)


Usage Notes:



Time bins are 300 seconds wide

Negative times indicate before flare peak, positive times after peak

Only time bins with sufficient data (>10 measurements) are included in plots

Normalization is performed by dividing by the maximum smoothed median value within ±10000s of peak

Spectral lines with insufficient data or known issues have been excluded


Spectral Line Information:

Lines are named as: element_ionization_wavelength_ntvExample: 'fe_12_195.12_ntv' = Fe XII 195.12 Å non-thermal velocity

Citation:Please cite the associated paper when using this data.

 

Python packages used for data curation:

Sunpy, EISPAC, Pandas, Astropy