Comparing the Properties of ICME-Induced Forbush decreases at Earth and Mars (CROSBI ID 276225)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Freiherr von Forstner, Johan L. ; Guo, Jingnan ; Wimmer- Schweingruber, Robert F. ; Dumbović, Mateja ; Janvier, Miho ; Demoulin, Pascal ; Veronig, Astrid ; Temmer, Manuela ; Papaioannou, Athanasios ; Dasso, Sergio ; Hassler, Donald M. ; Zeitlin, Cary J.
engleski
Comparing the Properties of ICME-Induced Forbush decreases at Earth and Mars
Abstract Forbush decreases (FDs), which are short-term drops in the flux of galactic cosmic rays (GCR), are caused by the shielding from strong and/or turbulent magnetic structures in the solar wind, especially interplanetary coronal mass ejections (ICMEs) and their associated shocks, as well as corotating interaction regions (CIRs). Such events can be observed at Earth, e.g. using neutron monitors, but also at many other locations in the solar system, such as on the surface of Mars with the Radiation Assessment Detector (RAD) instrument onboard Mars Science Laboratory (MSL). They are often used as a proxy for detecting the arrival of ICMEs or CIRs, especially when sufficient in situ solar wind measurements are not available. We compare the properties of FDs observed at Earth and Mars, focusing on events produced by ICMEs. We find that FDs at both locations show a correlation between their total amplitude and the maximum hourly decrease, but with different proportionality factors. We explain this difference using theoretical modelling approaches and suggest that it is related to the size increase of ICMEs, and in particular their sheath regions, en route from Earth to Mars. From the FD data, we can derive the sheath broadening factor to be between about 1.5 and 1.9, agreeing with our theoretical considerations. This factor is also in line with previous measurements of the sheath evolution closer to the Sun.
ICME, Forbush decrease, GCR, MSL, Mars mission, radiation
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o izdanju
n/a (n/a)
2020.
e2019JA027662
0
objavljeno
0148-0227
2156-2202
10.1029/2019JA027662