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A New Magnetic Field Activity Proxy for Mars From MAVEN Data
Author(s) -
Mittelholz A.,
Johnson C. L.,
Morschhauser A.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl078425
Subject(s) - mars exploration program , geophysics , interplanetary magnetic field , dipole model of the earth's magnetic field , geology , martian , interplanetary spaceflight , exploration of mars , magnetometer , ionosphere , solar wind , astrobiology , magnetic field , physics , remote sensing , quantum mechanics
The identification of magnetically quiet or noisy observations is important for data selection in a wide range of studies, including crustal field modeling and investigations of the ionosphere. However this remains a challenge when studying the magnetic field of Mars, as no continuous magnetic activity index is available. Such indices are widely used for studies of Earth's magnetic field, and they are largely based on data from ground observatories. We suggest a martian magnetic activity proxy based on satellite data, from the Mars Atmosphere and Volatile EvolutioN spacecraft (MAVEN). MAVEN has been in orbit since November 2014, providing measurements of the magnetic field that extend those from the Mars Global Surveyor mission. The proxy uses the magnitude of the interplanetary magnetic field upstream of the bow shock and is motivated by the correlation of the interplanetary magnetic field amplitude with the nightside magnetic field at 150‐ to 600‐km altitude, measured on the same MAVEN orbit. We demonstrate the utility of the proxy, by producing a model of the surface crustal field in a previously mapped low‐amplitude region in the vicinity of the InSight landing site. The proposed proxy successfully separates quiet and noisy data and will facilitate MAVEN data selection for higher‐resolution crustal field models. Other applications include data selection for magnetic sounding studies using the InSight magnetometer, or studies of the ionosphere. The deployment of a ground‐based magnetometer by InSight will also allow the refinement of the proxy, using simultaneous satellite and surface magnetic field measurements.