Naslov
A new model describing Forbush Decreases at Mars: combining the heliospheric modulation and the atmospheric influence

Autori
Guo, Jingnan ; Wimmer-Schweingruber, Robert F. ; Dumbović, Mateja ; Heber, Bernd ; Wang, Yuming

Izvornik
Earth and Planetary Physics (2096-3955) 4 (2020), 1; 62-72

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ICME and Forbush decreases, space weather at Mars, Mars: atmosphere, GCR radiation

Sažetak
Forbush decreases are depressions in the galactic cosmic rays (GCRs) which are mostly caused by the modulations of interplanetary coronal mass ejections (ICMEs) and also some- times by stream/corotating interaction regions (SIRs/CIRs). Forbush decreases have been studied extensively using neutron monitors at Earth and have been recently, for the first time, measured on the surface of another planet - Mars by the Radiation Assessment Detector (RAD), on board Mars Science Laboratory’s (MSL) rover Curiosity. The modulation of the GCR particles by heliospheric transients in space is energy-dependent and afterwards these particles are also interacting with the Martian atmosphere with the interaction process de- pending on the particle type and energy. In order to study the space weather environment near Mars using the ground-measured Forbush decreases, it is important to understand and quantify the energy- dependent modulation of the GCR particles by not only the pass-by he- liospheric disturbances but also the Martian atmosphere. In this study, we develop a model which combines the heliospheric modulation of GCRs and the atmospheric modification of such modulated GCR spectra to quantify the amplitudes of the Forbush decreases at Mars: both on ground and in the interplanetary space near Mars during the pass-by of an ICME/SIR. The modeled results are in good agreement when compared to studies of Forbush decreases caused by ICMEs/SIRs measured by MSL on the surface of Mars and by the Mars Atmo- sphere and Volatile EvolutioN (MAVEN) spacecraft in orbit. This supports the validity of both the Forbush decrease description and the Martian atmospheric transport models.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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