Forbush Decreases on the Martian Surface during the 2014 Mars Oppositio
Bernd Heber1, Arik Posner2, Robert F Wimmer-Schweingruber3, Henning Lohf1, Jingnan Guo4, Cary J Zeitlin5, Javier Martín-Torres6, María-Paz Zorzano6, Christian T Steigies7, Yihua Zheng8, Lars Berger9, Nina Dresing3, Christian Drews3, Konstantin Herbst10, Patrick Kühl3, Peter J MacNeice11, Dusan Odstrcil12, Lutz Rastaetter13, Rudolf Beaujean7, Soenke Burmeister1, Francis Cucinotta14, Bent Ehresmann15, Don Hassler16, Jan Kohler1, Cesar Martin-Garcia17, Reinhold Müller-Mellin7, Scot CR Rafkin18, Myung-Hee Y Kim19, Mark A Bullock18 and MSL/RAD engineering team, (1)University of Kiel, Kiel, Germany, (2)NASA Headquarters, SMD/Heliophysics Division, Washington, DC, United States, (3)University of Kiel, Institute for Experimental and Applied Physics, Kiel, Germany, (4)University of Science and Technology of China, School of Earth and Space Sciences, Hefei, China, (5)Southwest Research Institute, Oakland, CA, United States, (6)Centro de Astrobiologia, Madrid, Spain, (7)Christian-Albrechts-Universität zu Kiel, Kiel, Germany, (8)Community Coordinated Modeling Center, NASA Goddard Space Flight Center, Greenbelt, United States, (9)Kiel University, Kiel, Germany, (10)Organization Not Listed, Washington, DC, United States, (11)NASA Goddard Space Flight Center, Community Coordinated Modeling Center, Greenbelt, United States, (12)George Mason University Fairfax, Physics and Astronomy, Fairfax, VA, United States, (13)NASA Goddard Space Flight Center, Community Coordinated Modeling Center, Greenbelt, MD, United States, (14)University of Nevada Las Vegas, Las Vegas, NV, United States, (15)Southwest Research Institute Boulder, Solar System Science & Exploration Division, Boulder, CO, United States, (16)Southwest Research Institute, Boulder, United States, (17)IEAP, University of Kiel, Kiel, Germany, (18)Southwest Research Institute Boulder, Boulder, CO, United States, (19)Wyle Information Systems, Inc., Lanham, MD, United States
Abstract:
We analyze Forbush decreases that were observed both on the surface of the Earth and Mars during and around the time period of the Mars opposition in April 2014. More than 100 Forbush decreases were observed over one complete Martian year (the equivalent of 1.88 Earth years) since the landing of the Mars Science Laboratory in 2012. We find that several Forbush decreases occurred that can be linked to the same interplanetary structures affecting both planets. Observations of the Radiation Assessment Detector (RAD) and the Rover Environmental Monitoring Station (REMS), the neutron monitor network on Earth and of several other space missions are used for our analysis. We compare commonly observed Forbush decreases with respect to frequency, magnitude, and duration under the given solar cycle conditions and identify individual drivers of the Forbush decreases on Mars, i.e. recurrent and transient solar wind structures in the inner heliosphere.
