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Kovtyukh, A. S.

doi:10.1023/a:1013074126604

Cited by 17 publications

(20 citation statements)

References 131 publications

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“…High-energy part of the ion spectra in the PS, at R  2040 R E , has approximately the same shape as in the ERB and the average values of the parameters  b and  are close to our estimates of these parameters for the ERB. Moreover, the proton spectra in the ERB are consistent with the PS spectra not only in form but also in absolute fluxes: they can be obtain from the PS ion spectra in result of the simplest adiabatic transformations (for more details see in Kovtyukh, 1999bKovtyukh, , 2001).…”

Section: Discussionsupporting

confidence: 56%

“…Here B and B 0 are values of the magnetic field at the point of measurement and in the equatorial plane on the same L shell. For each of the main ion components of the ERB it was established that spatial, energy and pitch-angle distributions of fluxes are connected to each other with by means of the invariant parameters  m ,  0 ,  b ,  and  i (Kovtyukh, 1984(Kovtyukh, , 1994(Kovtyukh, , 1999a(Kovtyukh, , 2001). These parameters are completely determines the spatial-energy structure of the ERB ion fluxes in a wide region of the space {, L}.…”

Section: Invariants Of the Ion Earth's Radiation Belts Structurementioning

confidence: 99%

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Invariants of the Spatial-Energy Structure and Modeling of the Earth's Ion Radiation Belts

Kovtyukh

2019

Preprint

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Abstract. The spatial-energy distributions of proton fluxes in the Earth's radiation belts (ERB) are well studied and the NASA averaged empirical models constructed for them (the latest versions are AP8 and AP9). These models are widely used in space research. However, for heavier ERB ions (helium, oxygen, etc.), much less measurements were made on satellites, especially in the energy range from tens to hundreds of MeV, and there are no sufficiently complete and reliable models for them. Meanwhile, such ions, although there are much smaller than protons, play a very important role in the physics of ERB, especially in their dynamics, as well as in solving problems of ensuring the safety of space flights. The data on such ions represent a rather fragmentary picture, in which there are significant white spots. Using the methods considered in this paper, these fragmentary data can be streamlined, linked to each other and get a regular picture that has a simple physical meaning. Spatial-energy distributions of the stationary fluxes of protons, helium ions and ions of the CNO group with energy from 100 keV to 200 MeV at L ~ 1–8 considered here on the data of the satellites for 1961–2017. It is found, that results of the measurements of the ion fluxes are arrange in certain regular patterns in the spaces {E, L} and {L, B/B0}. This effect connected with the existence of invariant parameters of these distributions of ion fluxes. These invariant parameters are very useful and necessary for constructing the ion models of the ERB. The physical mechanisms leading to formation spatial-energy structure of the ERB ion fluxes and the values of its invariant parameters discussed here. In the course of this work, solar-cyclic (11-year) variations in the distributions of helium and carbon-nitrogen-oxygen ions fluxes in the ERB studied for the first time. It shown that, as compared with such variations in the proton fluxes studied earlier, the amplitude of the variations of heavier ions is much larger and increases with increasing their mass.

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Section: Discussionsupporting

confidence: 56%

Section: Invariants Of the Ion Earth's Radiation Belts Structurementioning

confidence: 99%

Invariants of the Spatial-Energy Structure and Modeling of the Earth's Ion Radiation Belts

Kovtyukh

2019

Preprint

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“…For protons with µ > 0.5 ± 0.2 keV nT −1 , such a situation can only be provided by mechanisms of the radial diffusion of particles to the Earth from the outer boundary of belts while conserving µ and K (Kovtyukh, 2001).…”

Section: Discussionmentioning

confidence: 99%

“…During the quiet periods, the protons considered here are the major contributors to the pressure of the trapped particles in the geomagnetic trap. Therefore, they can be regarded as a quiet ring current (see Kovtyukh, 2001). This belt of protons is called the ring current also in Williams (1981), the results of which are used in my work.…”

Section: Introductionmentioning

confidence: 99%

“…This belt of protons is called the ring current also in Williams (1981), the results of which are used in my work. However, at µ > 0.5 ± 0.2 keV nT −1 at L > 3, a belt of protons (and other trapped ions) in quiet and slightly disturbed periods is maintained in the stationary state mainly due to the radial diffusion of particles from the outer boundary of the trap to the Earth with conservation µ and K (Kovtyukh, 2001). For nonrelativistic protons with α 0 = 90…”

Section: Introductionmentioning

confidence: 99%

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Deduction of the rates of radial diffusion of protons from the structure of the Earth's radiation belts

Kovtyukh

2016

Ann. Geophys.

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Abstract. From the data on the fluxes and energy spectra of protons with an equatorial pitch angle of α 0 ≈ 90 • during quiet and slightly disturbed (Kp ≤ 2) periods, I directly calculated the value D LL , which is a measure of the rate of radial transport (diffusion) of trapped particles. This is done by successively solving the systems (chains) of integrodifferential equations which describe the balance of radial transport/acceleration and ionization losses of low-energy protons of the stationary belt. This was done for the first time. For these calculations, I used data of International SunEarth Explorer 1 (ISEE-1) for protons with an energy of 24 to 2081 keV at L = 2-10 and data of Explorer-45 for protons with an energy of 78.6 to 872 keV at L = 2-5. Ionization losses of protons (Coulomb losses and charge exchange) were calculated on the basis of modern models of the plasmasphere and the exosphere. It is shown that for protons with µ from ∼ 0.7 to ∼ 7 keV nT −1 at L≈ 4.5-10, the functions of D LL can be approximated by the following equivalent expressions:, where f d is the drift frequency of the protons (in mHz), D LL is measured in s −1 , E is measured in kiloelectronvolt and µ is measured in kiloelectronvolt per nanotesla. These results are consistent with the radial diffusion of particles under the action of the electric field fluctuations (pulsations) in the range of Pc6 and contradict the mechanism of the radial diffusion of particles under the action of sudden impulses (SIs) of the magnetic field and also under the action of substorm impulses of the electric field. During magnetic storms D LL increases, and the expressions for D LL obtained here can change completely.

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Anomalous dynamics of the extremely compressed magnetosphere during 21 January 2005 magnetic storm

et al. 2014

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The dayside magnetosphere and proton radiation belt were analyzed during unusual magnetic storm on 21 January 2005. We have found that from 1712 to 2400 UT, the subsolar magnetopause was continuously located inside geosynchronous orbit due to strong compression. The compression was extremely strong from 1846 to 2035 UT when the dense plasma of fast erupting filament produced the solar wind dynamic pressure that peaked up to > 100 nPa, and during the first time, the upstream solar wind was observed at geosynchronous orbit for almost 2 h. Under the extreme compression, the outer magnetosphere at L > 5 was pushed inward, and the outer radiation belt particles moved earthward, became adiabatically accelerated, and accumulated in the inner magnetosphere at L < 4 that produced the intensified ring current with an exceptionally long lifetime. The observations were compared with predictions of various empirical and first-principles models. All the models failed to predict the magnetospheric dynamics under the extreme compression when the minimal magnetopause distance was estimated to be~3 RE. The inconsistencies might result from distortions of plasma measurements by extreme heliospheric conditions consisting in very fast solar wind streams and intense fluxes of solar energetic particles. We speculated that anomalous dynamics of the magnetosphere could be well described by the models if the He abundance in the solar wind was assumed to be > 20%, which is well appropriate for erupting filaments and which is in agreement with the upper 27% threshold for the He/H ratio obtained from Cluster measurements.

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Untitled

Cited by 17 publications

References 131 publications

Invariants of the Spatial-Energy Structure and Modeling of the Earth's Ion Radiation Belts

Invariants of the Spatial-Energy Structure and Modeling of the Earth's Ion Radiation Belts

Deduction of the rates of radial diffusion of protons from the structure of the Earth's radiation belts

Anomalous dynamics of the extremely compressed magnetosphere during 21 January 2005 magnetic storm

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