Earth's radiation belts' ions: patterns of the spatial-energy structure and its solar-cyclic variations

Abstract. Spatial-energy distributions of the stationary fluxes of protons, helium, and ions of the carbon–nitrogen–oxygen (CNO) group, with energy from E ∼100 keV to 200 MeV, in the Earth's radiation belts (ERBs), at L∼1–8, are considered here using data from satellites during the period from 1961 to 2017. It has been found that the results of these measurements line up in the {E,L} space, following some regular patterns. The ion ERB shows a single intensity peak that moves toward Earth with increasing energy and decreasing ion mass. Solar-cyclic (11-year) variations in the distributions of protons, helium, and the CNO group ion fluxes in the ERB are studied. In the inner regions of the ERB, it has been observed that fluxes decrease with increasing solar activity and that the solar-cyclic variations of fluxes of Z≥2 ions are much greater than those for protons; moreover, it seems that they increase with increasing atomic number Z. It is suggested that heavier ion intensities peak further from the Earth and vary more over the solar cycle, as they have more strong ionization losses. These results also indicate that the coefficient DLL of the radial diffusion of the ERB ions changes much less than the ionization loss rates of ions with Z≥2 due to variations in the level of solar activity.

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Earth's radiation belts ions: Patterns of the spatial-energy structure and its solar-cyclic variations

10.5194/angeo-2019-152 ◽

2019 ◽

Author(s):

Alexander S. Kovtyukh

Keyword(s):

Solar Activity ◽

Atomic Number ◽

Radiation Belts ◽

Energy Structure ◽

Helium Ions ◽

Energy Distributions ◽

Physical Mechanisms ◽

Cyclic Variations ◽

Regular Patterns ◽

Earth's Radiation Belts

Abstract. Spatial-energy distributions of the stationary fluxes of protons, helium ions and ions of carbon-nitrogen-oxygen (CNO) group, with energy from E = 100 keV to 200 MeV, in the Earth's radiation belts (ERB), at L = 1–8, are considered here by the data of the satellites for 1961–2017. It is find that the results of these measurements line up in the space {E, L} by some regular patterns. Solar-cyclic (11-year) variations in the distributions of protons, helium ions and CNO group ions fluxes in the ERB are studied. In the inner regions of the ERB the ions fluxes decrease with increasing solar activity. It is find, the solar-cyclic variations of fluxes for ions with Z ≥ 2 are much greater than for protons and increase with increasing an atomic number Z of the ions. The possible physical mechanisms leading to formation of this spatial-energy structure and to the solar-cyclic variations of the ERB ion fluxes are discussed.

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Distribution of Earth's radiation belts' protons over the drift frequency of particles

Annales Geophysicae ◽

10.5194/angeo-39-171-2021 ◽

2021 ◽

Vol 39 (1) ◽

pp. 171-179

Author(s):

Alexander S. Kovtyukh

Keyword(s):

Solar Activity ◽

Radiation Belts ◽

Physical Processes ◽

The Earth ◽

Proton Fluxes ◽

Direct Measurements ◽

Drift Frequency ◽

Diffusion Rates ◽

Using Data ◽

Earth's Radiation Belts

Abstract. Using data on the proton fluxes of the Earth's radiation belts (ERBs) with energy ranging from 0.2 to 100 MeV on the drift L shells ranging from 1 to 8, the quasi-stationary distributions over the drift frequency fd of protons around the Earth are constructed. For this purpose, direct measurements of proton fluxes of the ERBs during the period from 1961 to 2017 near the geomagnetic equator were employed. The main physical processes in the ERB manifested more clearly in these distributions, and for protons with fd>0.5 mHz at L>3, their distributions in the {fd,L} space have a more regular shape than in the {E,L} space. It has also been found that the quantity of the ERB protons with fd ∼ 1–10 mHz at L∼2 does not decrease, as it does for protons with E > 10–20 MeV (with fd>10 mHz), but increases with an increase in solar activity. This means that the balance of radial transport and loss of ERB low-energy protons at L∼2 is disrupted in favor of transport of these protons: the effect of an increase in the radial diffusion rates with increasing solar activity overpowers the effect of an increase in the density of the dissipative medium.

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Distribution of the Earth's radiation belts protons over the drift frequency of particles

10.5194/angeo-2020-67 ◽

2020 ◽

Author(s):

Alexander S. Kovtyukh

Keyword(s):

Solar Activity ◽

Radiation Belts ◽

Dissipative Medium ◽

Physical Processes ◽

The Earth ◽

Proton Fluxes ◽

Direct Measurements ◽

Drift Frequency ◽

Diffusion Rates ◽

Earth's Radiation Belts

Abstract. On the base of generalized data on the proton fluxes of the Earth's radiation belts (ERB) with energy from E ~ 0.2 MeV to 100 MeV at drift shells L from ~ 1 to 8, constructed stationary distributions of the ERB protons over the drift frequency fd of protons around the Earth. For this, direct measurements of proton fluxes of the ERB in the period 1961–2017 near the plane of the geomagnetic equator were used. The main physical processes in the ERB manifested more clearly in these distributions, and for protons with fd > 0.5 mHz at L > 3 distributions of the ERB protons in the space {fd, L} have a more orderly form than in the space {E, L}. It has been found also that the quantity of the ERB protons with fd ~ 1–10 mHz at L ~ 2 does not decrease, as for protons with E > 10–20 MeV (with fd > 10 mHz), but increases with an increase in solar activity. This means that the balance of radial transport and losses of the ERB low-energy protons at L ~ 2 is disrupt in advantage of transport: for these protons, the effect of an increase in the radial diffusion rates with increasing in solar activity overpowers the effect of an increase in the density of the dissipative medium.

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Mapping Earth’s radiation belts using data from STS91 mission of AMS

Astroparticle Physics ◽

10.1016/j.astropartphys.2008.06.002 ◽

2008 ◽

Vol 30 (1) ◽

pp. 18-28 ◽

Cited By ~ 18

Author(s):

V. Plyaskin

Keyword(s):

Radiation Belts ◽

Using Data ◽

Earth's Radiation Belts

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

10.5194/angeo-2019-82 ◽

2019 ◽

Author(s):

Alexander S. Kovtyukh

Keyword(s):

Radiation Belts ◽

Ion Fluxes ◽

Energy Structure ◽

Energy Distributions ◽

Oxygen Ions ◽

Space Flights ◽

Physical Mechanisms ◽

Proton Fluxes ◽

White Spots ◽

First Time

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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