Role of plasma waves in Mars' atmospheric loss

Recent observations of plasma waves, electron fluxes, and ion fluxes in Mars' ionosphere indicate that ion heating may have had a significant impact on Mars' atmospheric loss. We discuss two energy sources of plasma waves: the solar wind interaction with Mars and field‐aligned currents in regions of crustal magnetic fields. These plasma waves can damp through cyclotron resonance with the O+ population in the ionosphere leading to heating and subsequent O+ escape supporting the ∼1025 atoms s−1 (∼0.4 kg/s) O+ outflow indicated by present‐day observations. A stronger solar wind and O+ source of ∼4 Gyr ago could support losses of ∼100 kg/s, enough to strip Mars' atmosphere or 10 m of water in a ∼0.3 Gyr period. The observational evidence for ion heating is, with current data sets, largely circumstantial so we suggest needed observations.

[1]  D. Mitchell,et al.  On the origin of aurorae on Mars , 2006 .

[2]  Oleg Korablev,et al.  Discovery of an aurora on Mars , 2005, Nature.

[3]  Wolfgang Baumjohann,et al.  Ion loss on Mars caused by the Kelvin–Helmholtz instability , 2004 .

[4]  H. Hayakawa,et al.  Solar Wind-Induced Atmospheric Erosion at Mars: First Results from ASPERA-3 on Mars Express , 2004, Science.

[5]  François Leblanc,et al.  Mars atmospheric escape and evolution; interaction with the solar wind , 2004 .

[6]  M. Acuna,et al.  Observations of low-frequency magnetic oscillations in the Martian magnetosheath, magnetic pileup region, and tail , 2004 .

[7]  R. Ergun,et al.  Auroral ion acceleration in dispersive Alfvén waves , 2004 .

[8]  Ignasi Ribas,et al.  Loss of water from Mars: Implications for the oxidation of the soil , 2003 .

[9]  E. Kallio,et al.  Solar EUV and electron-proton-hydrogen atom-produced ionosphere on Mars: comparative studies of particle fluxes and ion production rates due to different processes , 2002 .

[10]  Pekka Janhunen,et al.  Ion escape from Mars in a quasi‐neutral hybrid model , 2002 .

[11]  John R Wygant,et al.  Polar spacecraft based comparisons of intense electric fields and Poynting flux near and within the plasma sheet-tail lobe boundary to UVI images: An energy source for the aurora , 2000 .

[12]  Mats André,et al.  Theories and Observations of Ion Energization and Outflow in the High Latitude Magnetosphere , 1997 .

[13]  S. Barabash,et al.  Martian planetopause as seen by the plasma wave system onboard Phobos 2 , 1996 .

[14]  Rickard N. Lundin,et al.  Aspera/Phobos measurements of the ion outflow from the MARTIAN ionosphere , 1990 .

[15]  B. Hultqvist,et al.  First measurements of the ionospheric plasma escape from Mars , 1989, Nature.

[16]  N. Hershkowitz,et al.  Transverse acceleration of oxygen ions by electromagnetic ion cyclotron resonance with broad band left‐hand polarized waves , 1986 .

[17]  C. Cattell.  The relationship of field-aligned currents to electrostatic ion cyclotron waves , 1981 .

[18]  W. B. Hanson,et al.  The Martian ionosphere as observed by the Viking retarding potential analyzers , 1977 .

[19]  Charles F. Kennel,et al.  Topside current instabilities , 1971 .

[20]  H. Lammer,et al.  A comparison of magnetohydrodynamic instabilities at the Martian ionopause , 2004 .

[21]  Eos Sorce,et al.  Laboratory for Atmospheric and Space Physics , 2000 .

[22]  H. Rosenbauer,et al.  Ions of planetary origin in the Martian magnetosphere (Phobos 2/Taus experiment) , 1991 .