M-I coupling scales and energy dumping

Haerendel, G.

doi:10.1002/2014gl059582

Cited by 3 publications

(3 citation statements)

References 45 publications

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“…Some of the recent theoretical studies [e.g., Haerendel , ] also seem to suggest difference in acceleration altitude between the two types of aurora. Unfortunately, this conjecture has not been supported firmly by previous satellite/rocket observations.…”

Section: Discussionmentioning

confidence: 99%

Characteristics of monoenergetic and broadband auroral electron precipitation as observed by the Science and Technology Satellite‐I

et al. 2014

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Previously, the pitch angle distribution of monoenergetic and broadband electron precipitation has been investigated mainly by case studies. The main focus of this study is quantitative comparison of pitch angle distributions between monoenergetic and broadband electron precipitations using long-term observations on board one platform. From December 2003 to October 2004, Science and Technology Satellite-I (altitude∼680 km) regularly observed auroral electron flux and cold ambient plasma parameters during quiet and moderately disturbed conditions. Monoenergetic electron precipitation has notable perpendicular anisotropy, while broadband electron precipitation is much more field aligned. As for other features of monoenergetic and broadband electron precipitation, the characteristic energy of precipitating electrons is slightly higher for monoenergetic (around 1 keV) than for broadband electron precipitation (from several hundred eV to 1 keV). For both monoenergetic and broadband types, the characteristic energy and energy flux do not show clear correlation with cold ambient plasma density/temperature.

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Section: Discussionmentioning

confidence: 99%

Characteristics of monoenergetic and broadband auroral electron precipitation as observed by the Science and Technology Satellite‐I

et al. 2014

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“…Zhu et al [] showed that ionospheric irregularities can lead to field rotation of Alfvén waves, by which the coplanarity assumption mentioned above breaks down. Haerendel [] suggested that scale breaking of Alfvén waves results in maximum transport of energy from the magnetosphere to the ionosphere: so‐called self‐adjustment between Alfvénic and ionospheric conductance. According to Shi et al [], not only normal ionospheric reflection but also electron/wave interactions can affect Alfvén waves.…”

Section: Introductionmentioning

confidence: 99%

Alfvén waves in the auroral region, their Poynting flux, and reflection coefficient as estimated from Swarm observations

et al. 2017

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The European Space Agency's Swarm constellation can measure electric field, magnetic field, and plasma density on board multiple satellites at altitudes of about 500 km. Based on the data set at high latitudes, we estimate Poynting flux and ionospheric reflection coefficients of Alfvén waves with scale sizes of about 10–100 km. The reflection coefficients are generally higher surrounding the cusp and auroral regions than in the polar cap and higher in the summer than in the winter hemisphere. In the summer (winter) hemisphere the reflection coefficients generally peak on the dayside (nightside). Distributions of the reflection coefficients are not controlled by those of in situ plasma density. Poynting flux of the Alfvén waves maximizes surrounding the cusp and near‐midnight auroral region with magnitudes approaching 1 mW/m2, which are consistent with previous magnetospheric observations. The observed Poynting flux is downward on average for both hemispheres, and the magnitudes do not exhibit clear hemispheric asymmetry.

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“…The principle behind scale-breaking is the optimization of the energy dumping into the ionosphere (see Haerendel, 2014). This energy resides in the magnetic tensions acquired by the initial reflections at the ionosphere.…”

Section: Magnetosphere-ionosphere Couplingmentioning

confidence: 99%

Experiments With Plasmas Artificially Injected Into Near-Earth Space

Haerendel

2019

Front. Astron. Space Sci.

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Plasma injection experiments in space are being ordered according to five aspects: (1) Diagnostics of electric fields, (2) Coupling to the ionosphere, (3) Interactions with the solar wind, (4) Modification experiments, and (5) Special physical processes. Historically first were releases of neutral gases with the aim to measure atmospheric parameters. They were soon followed by plasma injections applied to the measurement of plasma flows and parallel electric fields. Long-range coupling to the environment was a most important aspect of the plasma releases. It concerned, on the one hand, the need for corrections of the derived diagnostic parameters and, on the other hand, the understanding of the formation of the ubiquitous striations and deformations of the plasma clouds. A special application was the investigation of cometary interactions by releases in the solar wind. Modification experiments in the ionosphere were done intentionally or occurred as byproducts of rocket launches or other activities. A particular goal was to trigger natural large-scale ionospheric instabilities like equatorial spread F in order to improve the understanding of the natural phenomena. Large-scale plasma injections in the magnetosphere have been performed in order to change the conditions of wave-particle interactions and potentially trigger observable effects. Special goals were so-called skidding experiments and testing Alfvén's critical ionization velocity effect. In this review, we will emphasize the principle objectives and illustrate the results from selected experiments.

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M-I coupling scales and energy dumping

Cited by 3 publications

References 45 publications

Characteristics of monoenergetic and broadband auroral electron precipitation as observed by the Science and Technology Satellite‐I

Characteristics of monoenergetic and broadband auroral electron precipitation as observed by the Science and Technology Satellite‐I

Alfvén waves in the auroral region, their Poynting flux, and reflection coefficient as estimated from Swarm observations

Experiments With Plasmas Artificially Injected Into Near-Earth Space

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