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Diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory Radiation Assessment Detector
Author(s) -
Rafkin Scot C. R.,
Zeitlin Cary,
Ehresmann Bent,
Hassler Don,
Guo Jingnan,
Köhler Jan,
WimmerSchweingruber Robert,
GomezElvira Javier,
Harri AriMatti,
Kahanpää Henrik,
Brinza David E.,
Weigle Gerald,
Böttcher Stephan,
Böhm Eckart,
Burmeister Söenke,
Martin Cesar,
Reitz Güenther,
Cucinotta Francis A.,
Kim MyungHee,
Grinspoon David,
Bullock Mark A.,
Posner Arik
Publication year - 2014
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1002/2013je004525
Subject(s) - mars exploration program , environmental science , atmospheric sciences , martian , exploration of mars , radiation , mars landing , martian surface , diurnal temperature variation , atmospheric escape , cosmic ray , atmosphere of mars , particle radiation , particle (ecology) , astrobiology , physics , meteorology , astronomy , charged particle , optics , ion , geology , oceanography , quantum mechanics
The Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.