Comparative studies of two similar SPEs as measured in LEO and outside Earth magnetosphere
Abstract
The effects on humans of Solar Particle Events (SPEs) inside a space habitat, are key knowledge for a proper risk assessment. Beside information from the radiobiological standpoint it is important to know how the SPEs will propagate to the habitat, in the habitat and how soon the warning concerning the SPE arrival can be issued. Validation of the related transport models, provision of SPE parameters - as inputs for optimizing the now-casting capabilities - are therefore of paramount importance (now-casting: ability to predict the risk associated to an SPEs from the very first radiation precursors as measured on the vessel itself). Here we focus on two SPEs (August 9th 2011 & March 13th 2012) as measured by ALTEA, an active silicon detector system orbiting in Low Earth Orbit (LEO) in the International Space Station (ISS). The SPEs observed by ALTEA are quite different from those detected outside Earth's magnetic field by e.g., GOES, the Geostationary Operational Environmental Satellite, as they are modulated by the geomagnetic shielding The shown measurements provide: i) experimental results of actual SPEs detected within a space habitat; ii) means to extrapolate these results to deep space; iii) information to better understand the interaction between the geomagnetic field and the radiation field from the sun. Results from the the two SPEs will be shown correlating the ALTEA data with data coming from other in-situ detectors, such as GOES and EPHIN taking into account the geomagnetic field cutoffs. Data from RAD instrument (in transit to Mars) will also be used for the comparison. Other publicly available data from detectors in LEO (such as PAMELA) will be used for the comparisons if available. We will also investigate the reasons of different ALTEA responses to similar SPEs.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2410N