Journal article
The Effects of Crustal Magnetic Fields and Solar EUV Flux on Ionopause Formation at Mars
Geophysical research letters, Vol.46(17-18), pp.10257-10266
09/01/2019
DOI: 10.1029/2019GL083499
Abstract
We study the ionopause of Mars using a database of 6,893 ionopause detections obtained over 11 years by the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment. The ionopause, in this work, is defined as a steep density gradient that appears in MARSIS remote sounding ionograms as a horizontal line at frequencies below 0.4 MHz. We find that the ionopause is located on average at an altitude of 363 +/- 65 km. We also find that the ionopause altitude has a weak dependence on solar zenith angle and varies with the solar extreme ultraviolet (EUV) flux on annual and solar cycle time scales. Furthermore, our results show that very few ionopauses are observed when the crustal field strength at 400 km is greater than 40 nT. The strong crustal fields act as minimagnetospheres that alter the solar wind interaction and prevent the ionopause from forming.
Details
- Title: Subtitle
- The Effects of Crustal Magnetic Fields and Solar EUV Flux on Ionopause Formation at Mars
- Creators
- F. Chu - University of IowaZ. Girazian - University of IowaD. A. Gurnett - University of IowaD. D. Morgan - University of IowaJ. Halekas - University of IowaA. J. Kopf - University of IowaE. M. B. Thiemann - Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USAF. Duru - Coe College
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.46(17-18), pp.10257-10266
- DOI
- 10.1029/2019GL083499
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Publisher
- Amer Geophysical Union
- Number of pages
- 10
- Grant note
- 1560641 / NASA; National Aeronautics & Space Administration (NASA) Jet Propulsion Laboratory
- Language
- English
- Date published
- 09/01/2019
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428674702771
Metrics
10 Record Views