Espisodic detachment of Martian crustal magnetic fields leading to bulk atmospheric plasma escape

Journal Article · Tue Jun 02 04:00:00 EDT 2009 · Geophysical Research Letters

OSTI ID:985479

Brain, D A; Baker, A H; Briggs, J; Eastwood, J P; Halekas, J S; Phan, T

We present an analysis of magnetic field and suprathermal electron measurements from the Mars Global Surveyor (MGS) spacecraft that reveals isolated magnetic structures filled with Martian atmospheric plasma located downstream from strong crustal magnetic fields with respect to the flowing solar wind. The structures are characterized by magnetic field enhancements and rotations characteristic of magnetic flux ropes, and characteristic ionospheric electron energy distributions with angular distributions distinct from surrounding regions. These observations indicate that significant amounts of atmosphere are intermittently being carried away from Mars by a bulk removal process: the top portions of crustal field loops are stretched through interaction with the solar wind and detach via magnetic reconnection. This process occurs frequently and may account for as much as 10% of the total present-day ion escape from Mars.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 985479
• Report Number(s): LLNL-JRNL-413528
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Vol. 37; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
99 GENERAL AND MISCELLANEOUS
ANGULAR DISTRIBUTION
ELECTRONS
ENERGY SPECTRA
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC RECONNECTION
PLASMA
REMOVAL
SOLAR WIND