Suprathermal Seed Populations

Download images reporting all of the seed population input parameters here.

Guidance on how to use the seed populations will be added. The idea is that modelers may apply a radial scaling to seed populations measured at 1 AU in order to convert them to spectra closer to the sun. iPATH described their approach to using these seed populations in a presentation at ISWAT 2021.

The suprathermal seed populations have been derived at 1 AU using measurements during quite periods prior to each SEP event. Seed populations were derived at Earth using ACE/ULEIS, ACE/EPAM, and Wind data. Seed populations were also derived at STEREO-A and B, when available. The ACE/ULEIS detector experiences high background levels particularly obvious during quiet times, so it is recommended that the ACE/ULEIS spectra provided here are not used.

A spectral form of a power law with an exponential rollover was fit to the data to provide the spectra in a form that may be input into SEP models.

The spectra are shown here, but the spectra along with plots of the solar wind conditions used to derive the spectra are shown on each of the individual SEP event pages.

2012-03-07

2012-05-17

2012-07-12

2013-04-11

2014-01-03 (for 2014-01-06 and 2014-01-07)

2017-07-14

2017-09-04

2017-09-10