T. K. Breus

Effects of magnetic anomalies discovered at Mars on the structure of the Martian ionosphere and solar wind interaction as follows from radio occultation experiments

The slopes of the electron density profiles obtained by radio occultation experiments at Mars revealed different variations with solar zenith angle in comparison with behavior of the electron density profiles in the magnetic field free ionosphere of Venus. The results obtained by the Mars-Global-Surveyor (MGS) spacecraft show the existence of highly variable and very localized magnetic fields of crustal origin at Mars. Addressing the difference between the ionosphere at Venus and Mars, the scale heights of electron density profiles obtained by radio occultation methods onboard Mariner 9 and Viking 1 are analyzed at altitudes higher than the topside boundary of the photoequlibrium region in the magnetic field-free ionosphere. The local increase of the mean scale height in the altitude region 180–250 km is assumed to be either an effect of a nonhorizontal magnetic field associated with the magnetic anomalies or diffusive equilibrium in the magnetic field free ionosphere. The areas where the scale height of electron density profile is increased in comparison with average one have been selected. The angle between the magnetic field measured by MGS MAG/ER at altitudes 120–250 km and local zenith direction is investigated throughout these selected areas.

Structure of the magnetic field fluxes connected with crustal magnetization and topside ionosphere at Mars

[1] The magnetic fluxes associated with the Martian crustal remanent magnetization have been studied in order to investigate the global structure of the magnetic field in and above the level of the Martian ionosphere. The intensely and nonuniformly magnetized crustal sources generate an effective large-scale magnetic field. Reconnection with the interplanetary magnetic field can possibly take place in many localized regions. This will permit solar wind (SW) and more energetic particles to precipitate into and heat the neutral atmosphere by impact ionization. This may occur not only in cusp-like field structures above nearly vertical field anomalies but also in halos extending several hundreds of kilometers from these sources. Numerous cusp-like regions may exist above the many crustal anomalies in the southern hemisphere. The large-scale horizontal magnetic fields due to the crustal sources and induced by the SW interaction are responsible for controlling the detailed structure of the Martian ionosphere. Radio occultation observations in the southern hemisphere show relatively constant and low average values of the electron density scale height and zero dependence on zenith angle in contrast to that of nonmagnetic Venus. INDEX TERMS: 2459 Ionosphere: Planetary ionospheres (5435, 5729, 6026, 6027, 6028); 6225 Planetology: Solar System Objects: Mars; 5443 Planetology: Solid Surface Planets: Magnetospheres (2756); 5440 Planetology: Solid Surface Planets: Magnetic fields and magnetism; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions; KEYWORDS: Mars, ionosphere, paleomagnetism, magnetosphere

Effect of geomagnetic field disturbances on the adaptive stress reaction of cosmonauts

Investigations of the effect of geomagnetic activity factors on the cardiac rhythm regulation and arterial pressure of cosmonauts during the expeditions onboard the Soyuz spacecraft, and the MIR and ISS orbital space stations was carried out for various durations of flight in weightlessness and, under control. Groups of cosmonauts were inspected under flight conditions outside the geomagnetic disturbances and in ground preflight conditions, during disturbances without them. The presence of specific effect of geomagnetic disturbances on the system of vegetative regulation of blood circulation of cosmonauts during the flight was demonstrated for the first time. The response of cosmonauts’ cardiac rhythm on the magnetic storm is definitely revealed; however, it depends on the initial functional background and, in particular, on the state of mechanisms of vegetative regulation (the duration of flight and adaptation to it).

Remnant magnetic fields of Mars and their interaction with the solar wind

This work presents a review of studies of the Martian magnetic fields during the early Soviet missions to Mars in 1971–1974, which never approached Mars by closer than 1000 km before the experiment with the Magnetometer/Electronic Reflectometer (MAG/ER) on board the Mars Global Surveyor spacecraft, which could descend to altitudes of 80–100 km. At present, the experiment with the magnetometer (MAG) onboard the American MAVEN spacecraft adds new data, but the map of distribution of remnant magnetic fields of Mars and the picture of their interaction with the solar wind are already formed and, at its core, obviously, will not be revised. Thus, it would be very instructive to consider the following in detail: (a) what is already known regarding the features and distribution of remnant magnetic fields on Mars; (b) how they control the interaction of solar wind with a weakly magnetized planet (Mars); and (c) what is its distinction from another nonmagnetized planet (Venus).

An unforgettable personality

This paper contains anecdotes concerning Konstantin Iosifovich Gringauz, his life, character, and scientific results. His transmitter-antenna system on Sputnik 1 announced the opening of the space era, and his scientific results, obtained during a period of 35 years, made a significant contribution to space physics.