Modeling Wind-Driven Ionospheric Dynamo Currents at Mars: Expectations for InSight Magnetic Field Measurements

DOI: 
10.1029/2019GL082536
Publication date: 
07/06/2019
Main author: 
Lillis R.J.
IAA authors: 
Gonzalez-Galindo, F.
Authors: 
Lillis R.J., Fillingim M.O., Ma Y., Gonzalez-Galindo F., Forget F., Johnson C.L., Mittelholz A., Russell C.T., Andersson L., Fowler C.M.
Journal: 
Geophysical Research Letters
Refereed: 
Yes
Publication type: 
Article
Pages: 
5083-5091
Abstract: 
We model expected dynamo currents above, and resulting magnetic field profiles at, InSight's landing site on Mars, including for the first time the effect of electron-ion collisions. We calculate their diurnal and seasonal variability using inputs from global models of the Martian thermosphere, ionosphere, and magnetosphere. Modeled currents primarily depend on plasma densities and the strength of the neutral wind component perpendicular to the combined crustal and draped magnetic fields that thread the ionosphere. Negligible at night, currents are the strongest in the late morning and near solstices due to stronger winds and near perihelion due to both stronger winds and higher plasma densities from solar EUV photoionization. Resulting surface magnetic fields of tens of nanotesla and occasionally >100 nT may be expected at the InSight landing site. We expect currents and surface fields to vary significantly with changes in the draped magnetic field caused by Mars' dynamic solar wind environment. ©2019. American Geophysical Union. All Rights Reserved.
Database: 
SCOPUS
ADS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066118830&doi=10.1029%2f2019GL082536&partnerID=40&md5=c62c9c11fe018ad421970bb6c1ecb041
ADS Bibcode: 
2019GeoRL..46.5083L
Keywords: 
current; dynamo; Insight; ionosphere; Magnetic; Mars