Low frequency waves in HF heating of the mid-latitude ionosphere

Surja Sharma, Bengt Eliasson, Xi Shao, Gennady Milikh, Dennis Papadopoulos

Research output: Contribution to conferencePaper

Abstract

The heating of the ionsosphere by high frequency (HF) radio waves leads to plasma processes with a wide range of scales. In the high-latitude ionosphere, extensive studies using numerical simulations using a Hall-magnetohydrodynamic model and experiments with the HAARP facility have provided a comprehensive understanding of the generation of low frequency hydromagnetic waves, both in the presence and absence of the auroral electrojet. Modulated HF heating in the F-region produces a local modulation of the electron temperature and the resulting pressure gradient give rise to a diamagnetic current, which in turn excites magnetosonic waves that propagate away from the heating region. In the E-region, where the Hall conductivity is dominant, these waves lead to oscillating Hall currents that produce shear Alfvén waves. These waves propagate along the field lines to the ground, where they are detected by ground-based magnetometers and into the magnetosphere. The observations of the shear Alfven waves by DEMETER satellite when its trajectory is over the HAARP magnetic zenith have shown the wave propagation to higher altitudes. For the mid latitude ionosphere the simulations use the Earth’s dipole magnetic field and the heating region is located at L = 1.6 and altitude of 300 km. With HF waves modulated at 2 – 10 Hz the low frequency waves are generated by essentially the same processes as in the high-latitude case, with additional features arising from the magnetic geometry of the mid-latitude ionosphere. The shear Alfven waves propagating to the magnetosphere become electromagnetic ion cyclotron (EMIC) waves at higher altitudes but do not propagate beyond the ion cyclotron resonance layer. The heating of the ionosphere generates many plasma modes, viz., the Alfven, magnetosonic, helicon, whistler and electromagnetic ion cyclotron waves, and comparison of their properties with measurements during experiments (Arecibo and Sura) will be presented.

Conference

Conference14th International Ionospheric Effects Symposium IES2015
CountryUnited States
CityAlexandria, Virginia
Period12/05/1514/05/15

Fingerprint

ionospheres
low frequencies
heating
magnetohydrodynamic waves
high altitude
shear
magnetospheres
polar regions
cyclotrons
auroral electrojets
electromagnetism
Hall currents
ions
E region
radio waves
F region
zenith
cyclotron resonance
pressure gradients
magnetometers

Keywords

  • ionosphere
  • heating
  • low-frequency waves
  • excitation
  • hydromagnetic waves
  • electromagnetic ion cyclotron

Cite this

Sharma, S., Eliasson, B., Shao, X., Milikh, G., & Papadopoulos, D. (2015). Low frequency waves in HF heating of the mid-latitude ionosphere. 1-8. Paper presented at 14th International Ionospheric Effects Symposium IES2015, Alexandria, Virginia, United States.
Sharma, Surja ; Eliasson, Bengt ; Shao, Xi ; Milikh, Gennady ; Papadopoulos, Dennis. / Low frequency waves in HF heating of the mid-latitude ionosphere. Paper presented at 14th International Ionospheric Effects Symposium IES2015, Alexandria, Virginia, United States.8 p.
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abstract = "The heating of the ionsosphere by high frequency (HF) radio waves leads to plasma processes with a wide range of scales. In the high-latitude ionosphere, extensive studies using numerical simulations using a Hall-magnetohydrodynamic model and experiments with the HAARP facility have provided a comprehensive understanding of the generation of low frequency hydromagnetic waves, both in the presence and absence of the auroral electrojet. Modulated HF heating in the F-region produces a local modulation of the electron temperature and the resulting pressure gradient give rise to a diamagnetic current, which in turn excites magnetosonic waves that propagate away from the heating region. In the E-region, where the Hall conductivity is dominant, these waves lead to oscillating Hall currents that produce shear Alfv{\'e}n waves. These waves propagate along the field lines to the ground, where they are detected by ground-based magnetometers and into the magnetosphere. The observations of the shear Alfven waves by DEMETER satellite when its trajectory is over the HAARP magnetic zenith have shown the wave propagation to higher altitudes. For the mid latitude ionosphere the simulations use the Earth’s dipole magnetic field and the heating region is located at L = 1.6 and altitude of 300 km. With HF waves modulated at 2 – 10 Hz the low frequency waves are generated by essentially the same processes as in the high-latitude case, with additional features arising from the magnetic geometry of the mid-latitude ionosphere. The shear Alfven waves propagating to the magnetosphere become electromagnetic ion cyclotron (EMIC) waves at higher altitudes but do not propagate beyond the ion cyclotron resonance layer. The heating of the ionosphere generates many plasma modes, viz., the Alfven, magnetosonic, helicon, whistler and electromagnetic ion cyclotron waves, and comparison of their properties with measurements during experiments (Arecibo and Sura) will be presented.",
keywords = "ionosphere, heating, low-frequency waves, excitation, hydromagnetic waves, electromagnetic ion cyclotron",
author = "Surja Sharma and Bengt Eliasson and Xi Shao and Gennady Milikh and Dennis Papadopoulos",
year = "2015",
month = "5",
day = "14",
language = "English",
pages = "1--8",
note = "14th International Ionospheric Effects Symposium IES2015 ; Conference date: 12-05-2015 Through 14-05-2015",

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Sharma, S, Eliasson, B, Shao, X, Milikh, G & Papadopoulos, D 2015, 'Low frequency waves in HF heating of the mid-latitude ionosphere' Paper presented at 14th International Ionospheric Effects Symposium IES2015, Alexandria, Virginia, United States, 12/05/15 - 14/05/15, pp. 1-8.

Low frequency waves in HF heating of the mid-latitude ionosphere. / Sharma, Surja; Eliasson, Bengt; Shao, Xi; Milikh, Gennady; Papadopoulos, Dennis.

2015. 1-8 Paper presented at 14th International Ionospheric Effects Symposium IES2015, Alexandria, Virginia, United States.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Low frequency waves in HF heating of the mid-latitude ionosphere

AU - Sharma, Surja

AU - Eliasson, Bengt

AU - Shao, Xi

AU - Milikh, Gennady

AU - Papadopoulos, Dennis

PY - 2015/5/14

Y1 - 2015/5/14

N2 - The heating of the ionsosphere by high frequency (HF) radio waves leads to plasma processes with a wide range of scales. In the high-latitude ionosphere, extensive studies using numerical simulations using a Hall-magnetohydrodynamic model and experiments with the HAARP facility have provided a comprehensive understanding of the generation of low frequency hydromagnetic waves, both in the presence and absence of the auroral electrojet. Modulated HF heating in the F-region produces a local modulation of the electron temperature and the resulting pressure gradient give rise to a diamagnetic current, which in turn excites magnetosonic waves that propagate away from the heating region. In the E-region, where the Hall conductivity is dominant, these waves lead to oscillating Hall currents that produce shear Alfvén waves. These waves propagate along the field lines to the ground, where they are detected by ground-based magnetometers and into the magnetosphere. The observations of the shear Alfven waves by DEMETER satellite when its trajectory is over the HAARP magnetic zenith have shown the wave propagation to higher altitudes. For the mid latitude ionosphere the simulations use the Earth’s dipole magnetic field and the heating region is located at L = 1.6 and altitude of 300 km. With HF waves modulated at 2 – 10 Hz the low frequency waves are generated by essentially the same processes as in the high-latitude case, with additional features arising from the magnetic geometry of the mid-latitude ionosphere. The shear Alfven waves propagating to the magnetosphere become electromagnetic ion cyclotron (EMIC) waves at higher altitudes but do not propagate beyond the ion cyclotron resonance layer. The heating of the ionosphere generates many plasma modes, viz., the Alfven, magnetosonic, helicon, whistler and electromagnetic ion cyclotron waves, and comparison of their properties with measurements during experiments (Arecibo and Sura) will be presented.

AB - The heating of the ionsosphere by high frequency (HF) radio waves leads to plasma processes with a wide range of scales. In the high-latitude ionosphere, extensive studies using numerical simulations using a Hall-magnetohydrodynamic model and experiments with the HAARP facility have provided a comprehensive understanding of the generation of low frequency hydromagnetic waves, both in the presence and absence of the auroral electrojet. Modulated HF heating in the F-region produces a local modulation of the electron temperature and the resulting pressure gradient give rise to a diamagnetic current, which in turn excites magnetosonic waves that propagate away from the heating region. In the E-region, where the Hall conductivity is dominant, these waves lead to oscillating Hall currents that produce shear Alfvén waves. These waves propagate along the field lines to the ground, where they are detected by ground-based magnetometers and into the magnetosphere. The observations of the shear Alfven waves by DEMETER satellite when its trajectory is over the HAARP magnetic zenith have shown the wave propagation to higher altitudes. For the mid latitude ionosphere the simulations use the Earth’s dipole magnetic field and the heating region is located at L = 1.6 and altitude of 300 km. With HF waves modulated at 2 – 10 Hz the low frequency waves are generated by essentially the same processes as in the high-latitude case, with additional features arising from the magnetic geometry of the mid-latitude ionosphere. The shear Alfven waves propagating to the magnetosphere become electromagnetic ion cyclotron (EMIC) waves at higher altitudes but do not propagate beyond the ion cyclotron resonance layer. The heating of the ionosphere generates many plasma modes, viz., the Alfven, magnetosonic, helicon, whistler and electromagnetic ion cyclotron waves, and comparison of their properties with measurements during experiments (Arecibo and Sura) will be presented.

KW - ionosphere

KW - heating

KW - low-frequency waves

KW - excitation

KW - hydromagnetic waves

KW - electromagnetic ion cyclotron

UR - http://www.bc.edu/research/isr/ies2015.html

M3 - Paper

SP - 1

EP - 8

ER -

Sharma S, Eliasson B, Shao X, Milikh G, Papadopoulos D. Low frequency waves in HF heating of the mid-latitude ionosphere. 2015. Paper presented at 14th International Ionospheric Effects Symposium IES2015, Alexandria, Virginia, United States.