Electron temperatures in the <i>F</i> region of the ionosphere: Theory and observations

Schunk, R. W.; Nagy, Andrew F.

doi:10.1029/rg016i003p00355

Cited by 443 publications

(362 citation statements)

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“…In the region of the F-layer maximum where the electron-ion collision frequency is much higher than the electron-neutral collision frequency, the electronic thermal conductivity coefficient (κ e ) increases rapidly with electron temperature: κ e ∼ T 5/2 e (Gurevich, 1978;Schunk and Nagy, 1978). Hence, doubling the ERP does not double the electron temperature.…”

Section: Discussionmentioning

confidence: 96%

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Ashrafi

Kosch

Honary

2006

Advances in Space Research

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On 12 November 2001, artificial optical annuli were produced using the EISCAT highfrequency (HF) ionospheric Heating facility. This unusual phenomenon was induced using O-mode transmissions at 5.423 MHz with 550 MW effective isotropic radiated power and the pump beam dipped 9 degrees south. The pump frequency corresponds to the fourth electron gyro-harmonic frequency at 215 km altitude. The EISCAT UHF radar observed a persistent pump-induced enhancement in the ion line data near the HF reflection altitude. The optical and radar signatures of HF pumping started at ∼230 km and descended to ∼220 km within ∼60 s. This effect has been modelled using the solution to differential equations describing pump-induced electron temperature and density perturbations. The decrease in altitude of the ion line by ∼10 km and changes in electron density have been modelled. The results show that an electron temperature enhancement of up to ∼5700 K can be achieved, which is not sufficient to explain the observed optical emissions.

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Section: Discussionmentioning

confidence: 96%

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Ashrafi

Kosch

Honary

2006

Advances in Space Research

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“…For day-time F-region conditions the electron heating is dominated by photoelectron electron heating, Q e* [Schunk and Nagy, 1978]. Since the photoionization rate depends on the neutral density and the EUV photon flux, the amplitude and altitude variation of Q e* also depends on the neutral atmosphere density.…”

Section: Appendix A: Electron Heating As a Means To Estimate Neutral mentioning

confidence: 99%

Rise and fall of electron temperatures: Ohmic heating of ionospheric electrons from underdense HF radio wave pumping

et al. 2010

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[1] Here we present electron temperature variations observed with incoherent scatter radar during a European Incoherent Scatter Scientific Association Heating experiment with high-frequency (HF) radio wave transmission at frequencies above the peak ionospheric critical frequency. The electron temperature increased from 2000 K up to 2800 K during the HF transmission periods. During the experiment both pump frequency and polarization were altered between pump pulses. The observed temperature variation is compared with numerical solutions to the electron energy equation with ohmic heating modeling the effect of the radio wave heating of the plasma. Agreement between observations and model is found to be good.

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“…5 and 8-9• The thro;-s terms were shown in the review paper by Schunk and Nagy (1978) and were first given by Hoegy (1977) ► however the early form of the surface term was an approximation of the complete form given by Eq. 9.…”

Section: Thermal Electron Heating Ratementioning

confidence: 99%

“…The energy moments of the electron-ion and electron-neutral collision operators yield the thermal electron cooling rates which have been discussed in the literature (see Schunk and Nagy, 1978). The electron heating rate is derived by evaluating the integrals in rq.…”

Section: Basic Equationsmentioning

confidence: 99%

“…The other two terms are significant and therefore can not be neglected. The reader is referred '.,o the review paper by Schunk and Nagy (1978) for a general discussion of ionospheric electron temperature theory and observations, and for further references. The remainder of this paper is devoted to the thermal electron heating rate, ]tow it is derived, a formula for it, and some numerical examples.…”

Section: Introductionmentioning

confidence: 99%

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Thermal electron heating rate: A derivation

Hoegy¹

1984

J. Geophys. Res.

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The thermal electron heating rate, Qe , is an important heat source term in the ionospheric electron energy balance equation, representing heating by photoelectrons or by precipitating higher energy electrons. A formula for the thermal electron heating rate is derived from the kinetic equation using the electron-electron collision operator as given by the unified theory of Kihara and Aono. This collision operator includes collective interactions to produce a finite collision operator with an exact Coulomb logarithm term. The derived heating rate Qe is the sum of three terms, Q e = Qp + S + Qint, which are respectively: 1) primary electron production term giving the heating from

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Electron temperatures in the F region of the ionosphere: Theory and observations

Cited by 443 publications

References 235 publications

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Rise and fall of electron temperatures: Ohmic heating of ionospheric electrons from underdense HF radio wave pumping

Thermal electron heating rate: A derivation

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