DOI: 10.5281/zenodo.7385459
title: Solar wind parameters and geomagnetic indices for severe (SYM-H < -100nT) geomagnetic storms over two solar cycles

description: Severe storms data set (1996-2022)

Lotz, Grant, Davel (2024).

Changes from previous version:



Previous version had errors in calculation of `HER_eh` and `ABK_eh`.  The mistake is corrected in this version.

This version includes storms from 1996-2022. Previous version had 1996-2019.


This data set is curated from 1-minute time resolution OMNI [4] and INTERMAGNET [7] data, spanning the period 1996 - 2022.

It consists of all geomagnetic storms that reached minimum SYM-H (Symmetric-H index) of < -100 nT. We classified these as "severe" storms. There are 115 such events in the period 1996 - 2018. No severe storms detected between 2007-2010 or in 2019. Each file in the set contains the events in that year (YYYY) in the format "severe_YYYY.pickle".  The geomagnetic storms are identified by the procedure described in [1], with thresholds -100 nT and -20 nT (see [1] for further detail).

The data sets are Pandas "dataframes" [2], saved in the Python "pickle" format [3]. Each dataframe contains 23 variables, listed in the table below, with their description and unit.

Fourteen of the parameters are solar wind plasma and magnetic field parameters from the High Resolution OMNI data set [4].

There are 7 geomagnetic variables:



one is the global Sym-H index,

four are H-component geomagnetic observations from Hermanus, South Africa (HER: 34.4 S, 19.22 E) and Abisko, Sweden (ABK: 68.35 N, 18.82 E) and their time derivatives

two are the e_h index [5] calculated at HER and ABK


Finally, we list the time shift applied to each data point to shift to the bow shock nose (described for OMNI at [6]) and a string identifier for each geomagnetic storm.

 




#
Name
Description
Unit


1
time_shift


Time shift applied to shift solar wind parameters to bow shock

s


2
Bt
Magnitude of interplanetary magnetic field (IMF)
nT


3
Bx
X-component of IMF
nT


4
By_GSE
Y-component of IMF (GSE coordinates)
nT


5
Bz_GSE
Z-component of IMF (GSE coordinates)
nT


6
By_GSM
Y-component of IMF (GSM coordinates)
nT


7
Bz_GSM
Z-component of IMF (GSM coordinates)
nT


8
Vsw
Bulk solar wind speed
km/s


9
Vx
X-component of solar wind
km/s


10
Vy
Y-component of solar wind
km/s


11
Vz
Z-component of solar wind
km/s


12
Np
Proton number density in solar wind plasma
#/cc


13
Temp
Temperature of solar wind plasma
K


14
Pd
Dynamic or flow pressure of solar wind plasma
nPa


15
E_field
Solar wind electric field
mV/km


16
SymH
Symmetric-H index of the geomagnetic field
nT


17
HER_H
H-component of the geomagnetic field at Hermanus
nT


18
HER_dHdt
Time derivative of HER_H
nT/min


19
HER_eh
e_h index at HER
nT/min


20
ABK_H
H-component of the geomagnetic field at Abisko
nT


21
ABK_dHdt
Time derivative of ABK_H
nT/min


22
ABK_eh
e_h index at ABK
nT/min


23
Storm_ID
String identifier of the geomagnetic storm
-




 

References



Lotz, S. I., & Danskin, D. W. (2017). Space Weather, 15, 1347– 1356. https://doi.org/10.1002/2017SW001662

https://omniweb.gsfc.nasa.gov/ow_min.html

https://pandas.pydata.org/

https://docs.python.org/3/library/pickle.html

Wintoft, P., Wik, M., & Viljanen, A. J. Space Weather Space Clim., 5, A7 (2015). http://dx.doi.org/10.1051/swsc/2015008

https://omniweb.gsfc.nasa.gov/html/ow_data.html#time_shift

http://www.intermagnet.org