HR: 14:25h
AN: P52B-04    [PDF]
TI: The Solar Wind Interaction with Ionosphere/Atmosphere in the Northern Hemisphere of Mars
AU: * Krymskii, A M
EM: amkrym@yahoo.com
AF: Rostov State University, ul. Zorge 5 Space Physics Department, 344104, Rostov-on-Don, 117810 Russian Federation
AU: Ness, N F
EM: nfness@bartol.udel.edu
AF: Bartol Research Institute, 104 Center Mall, Rm. 217 University of Delaware, Newark, DE 19716 United States
AU: Crider, D H
EM: dcrider@lepvax.gsfc.nasa.gov
AF: The Catholic University of America, Department of Physics, Washington, DC 20064 United States
AU: Breus, T K
EM: breus@space.ru
AF: Space Research Institute (IKI), Profsoyuzaya, 84/32, Moscow, 117810 Russian Federation
AU: Acuna, M H
EM: mario.acuna@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Mail Code 695, Greenbelt, MD 20771 United States
AU: Hinson, D P
EM: hinson@rocc.stanford.edu
AF: Department of Electrical Engineering, Stanford University, Stanford, CA 94305-9515 United States
AU: Bojkov, D I
EM: denisbius@yahoo.com
AF: Rostov State University, ul. Zorge 5 Space Physics Department, 344104, Rostov-on-Don, 117810 Russian Federation
AB: In the Northern hemisphere, the crustal fields are rather weak and usually do not prevent direct interaction between the Solar Wind (SW) and the Martian ionosphere/atmosphere. Exceptions occur in the isolated mini-magnetospheres formed by the crustal anomalies. Electron density profiles of the ionosphere of Mars derived from radio occultation data obtained by the Radio Science Mars Global Surveyor (MGS) experiment have been compared with the crustal magnetic fields measured by the MGS Magmetometer/Electron Reflectometer (MAG/ER) experiment. A study of 523 electron density profiles obtained at latitudes from $+67\deg$ to $+77\deg$ has been conducted. The effective scale-height of the electron density for two altitude ranges, 145-165 km and 165-185 km, and the effective scale-height of the neutral atmosphere density in the vicinity of the ionization peak have been derived for each of the profiles studied. The thermal pressure of the ionospheric plasma at 160 km has been estimated. The solar wind interaction with the ionosphere of Mars and the origin of the sharp drop of the electron density at 200-210 km is discussed. For three SZA intervals, the longitudinal variations of the effective scale-height of the neutral atmosphere density in the vicinity of the ionization peak (135 km) have been analyzed. The longitudinal variations disappear where the solar zenith angles are minimal and where the crustal magnetic field at 140-150 km is approximately vertical. Presumably, the compression of the mini-magnetosphere formed by the isolated crustal anomalies and the "cusps" do not allow the crustal magnetic fields to protect the atmosphere from the precipitating energetic particles.
DE: 2459 Planetary ionospheres (5435, 5729, 6026, 6027, 6028)
DE: 5407 Atmospheres--evolution
DE: 5421 Interactions with particles and fields
DE: 5440 Magnetic fields and magnetism
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting