In Situ Data and Effect Correlation During September 2017 Solar Particle Event

Abstract

Solar energetic particles are one of the main sources of particle radiation seen in space. In the first part of September 2017 the most active solar period of cycle 24 produced four large X-class flares and a series of (interplanetary) coronal mass ejections, which gave rise to radiation storms seen over all energies and at the ground by neutron monitors. This paper presents comprehensive cross comparisons of in situ radiation detector data from near-Earth satellites to give an appraisal on the state of present data processing for monitors of such particles. Many of these data sets have been the target of previous cross calibrations, and this event with a hard spectrum provides the opportunity to validate these results. As a result of the excellent agreement found between these data sets and the use of neutron monitor data, this paper also presents an analytical expression for fluence spectrum for the event. Derived ionizing dose values have been computed to show that although there is a significant high-energy component, the event was not particularly concerning as regards dose effects in spacecraft electronics. Several sets of spacecraft data illustrating single event effects are presented showing a more significant impact in this regard. Such a hard event can penetrate thick shielding; human dose quantities measured inside the International Space Station and derived through modeling for aircraft altitudes are also presented. Lastly, simulation results of coronal mass ejection propagation through the heliosphere are presented along with data from Mars-orbiting spacecraft in addition to data from the Mars surface.

Effects of the 10 September 2017 Solar Flare on the Density and Composition of the Thermosphere of Mars

“…A series of intense solar storms in September 2017 launched a succession of solar flares, coronal mass ejections (CMEs), and solar energetic particles (SEPs) into the heliosphere (Bruno et al., 2019; Chamberlin et al., 2018; Jiggens et al., 2019; C. O. Lee, Jakosky, et al., 2018; Luhmann et al., 2018).…”

Origin of the Extended Mars Radar Blackout of September 2017

“…The Active Region (AR) 12673 at the western limb of the solar disk during September 2017 was very productive in terms of Earth‐directed X‐class solar flares and ICMEs (e.g., Jiggens et al, ; Redmon et al, ). The same AR also emitted a X8.2‐class flare on 10 September 2017 starting at ~15:35 UT and peaking at ~16:06 UT, and released a powerful CME at ~15:54 UT (Guo et al, ; Lee et al, ).…”

Solar Energetic Proton Access to the Magnetosphere During the 10–14 September 2017 Particle Event

“…Thus, we are not concerned with obtaining absolute flux values from GOES. Attempts to harmonize the GOES fluxes to each other and to other sensors have been published and are ongoing (Jiggens et al, 2018;Rodriguez et al, 2017;Sandberg et al, 2014).…”