Search Publications
Solar Energetic Proton Fluxes in Near-Earth Space on March 13-23, 2023
Vlasova, N. A.; Bazilevskaya, G. A.; Ginzburg, E. A. +5 more
The results of studying the fluxes of solar protons with energies greater than 5 MeV in near-Earth space on March 13-23, 2023, are presented. The features of the period under study are no visible solar flare with which the beginning of the event could be associated and an untypical time profile of proton fluxes, as well as a long duration of the e…
Earth's Ionospheric Response to Solar Activity Phenomena in February-March 2023
Sheiner, O. A.; Vybornov, F. I.
As a result of the analysis of data from vertical and oblique sounding of the ionosphere in February-March 2023 using the new ionospheric index, it was found that solar coronal mass ejections (CMEs) of the loop type lead to a long-term decrease in the critical frequencies F-layer of the ionosphere, while other types of CMEs may not lead to signifi…
New 1.38-µm Water Vapor Band Spectroscopy for a CO2 Atmosphere: H2O Measurements in the Martian Atmosphere in the SPICAM/MEX and ACS NIR/TGO Experiments
Montmessin, F.; Fedorova, A. A.; Korablev, O. I. +5 more
The H2O 1.38-µm band has been used to measure water vapor in the Martian atmosphere since the MAWD (Mars Atmospheric Water Detector) experiment on Viking-1 and -2. Currently, two experiments in orbit around Mars—SPICAM IR (SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars InfraRed) on Mars Express and A…
Geomagnetic Pulsations in the 1-4 mHz Frequency Range (Pc5/Pi3) in the Magnetotail. Internal and Extramagnetospheric Sources
Yagova, N. V.; Evsina, N. S.
Spectral and spatial parameters of nonstorm Pc5/Pi3 geomagnetic pulsations in the geomagnetic tail are studied based on magnetic measurements on Cluster satellites under different conditions in the interplanetary medium. Both the average values of the magnetic field components in front of the bow shock and fluctuations in the pulsations' frequency…
Coronal Propagation of Solar Protons during and after Their Stochastic Acceleration
Logachev, Yu. I.; Struminsky, A. B.; Grigorieva, I. Yu. +1 more
Solar protons in eruptive flares are stochastically accelerated in a wide spatial angle, and then they are effectively kept behind the expanding coronal mass ejection (CME) front, which can either bring protons to the magnetic-field line going to a remote observer or carry them away. We consider 13 solar proton events of cycle 24 in which protons …
High-Cadence Observations of Magnetic Field Dynamics and Photospheric Emission Sources in the Eruptive Near-the-Limb X4.9 Solar Flare on 25 February, 2014: Evidences for Two-Stage Magnetic Reconnection during the Impulsive Phase
Zimovets, I. V.; Sharykin, I. N.; Radivon, A. V.
We present an analysis of the pre-limb eruptive X4.9 solar flare on February 25, 2014, by means of which we confirm a hypothesis of the two-stage energy release corresponding to two magnetic reconnection regimes in the flare impulsive phase. This flare is selected, firstly, because of its morphological peculiarities suggesting the presence of the …
The Influence of Oxygen Ions on the Formation of a Thin Current Sheet in the Magnetotail
Malova, H. V.; Popov, V. Yu.; Zelenyi, L. M. +2 more
A thin current sheet in the Earth's magnetotail with characteristic thickness of one to several proton gyroradii is often observed during magnetospheric disturbances named substorms, when a relatively thick current configuration in the magnetotail is narrowed to an extremely small thickness and then can spontaneously be destroyed. The current-shee…
Estimation of the Electron Density in the Near 3-4 RE Magnetosphere Based on the Measurement of the Interball-2 Satellite Potential
Smirnova, N. F.; Stanev, G.
A new method is proposed for determining the electron density in rarefied plasma, based on simultaneous measurements of the Interball-2 satellite potential using IESP-2 (electric field instrument) and KM-7 (electron temperature sensor) probe devices. This makes it possible to estimate the photoelectron current density based on a procedure proposed…
Catalogs of Solar Proton Events as a Tool for Studying Space Weather
Vlasova, N. A.; Bazilevskaya, G. A.; Ginzburg, E. A. +8 more
Distinguishing features of a series of solar proton event (SPE) catalogs for the 20th-24th cycles of solar activity are described. The results of a comparative analysis of the 23rd and 24th cycles of solar activity performed according to the data of a series of SPE catalogs are presented. The opportunities provided by SPE catalogs for studying spa…
Physical Calibrations of the FREND Instrument Installed Onboard TGO Martian Orbiter
Mitrofanov, I. G.; Golovin, D. V.; Litvak, M. L. +10 more
The article presents results of ground calibrations of the FREND neutron telescope installed onboard the TGO spacecraft of the Russian-European ExoMars project. The main goal of the FREND space experiment is to measure hydrogen content in the subsurface layer of Mars to a depth of 1 m. High resolution maps of water mass fraction in the regolith ar…