Introduction to ionospheric heating at Tromsø—I. Experimental overview

Rietveld, M. T.; Kohl, H.; Kopka, H.; Stubbe, P.

doi:10.1016/0021-9169(93)90007-l

Cited by 227 publications

(191 citation statements)

References 62 publications

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“…[9] The EISCAT facility in Tromsø, northern Norway (69.58°N, 19.23°E), includes two incoherent scatter radars, UHF at 933 MHz and VHF at 224 MHz [Rishbeth and van Eyken, 1993], and is colocated with a high-power HF pump facility for artificial heating of the ionospheric plasma operating between 3.85 and 8 MHz [Rietveld et al, 1993].…”

Section: Experiments and Datamentioning

confidence: 99%

Angular dependence of pump-induced bottomside and topside ionospheric plasma turbulence at EISCAT

et al. 2011

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[1] We experimentally observe the location and angular size of the high-frequency (HF) radio window in the bottomside ionosphere, which permits radio wave propagation to the topside ionosphere, with high angular resolution at the European Incoherent Scatter (EISCAT) facility. HF pump-induced ion line enhancements were observed by the EISCAT UHF incoherent scatter radar on the ionospheric bottomside and topside. The radar zenith angle was scanned in small steps in the magnetic meridian. The HF pump duty cycle was deliberately kept low enough to minimize the growth of artificial field-aligned irregularities. The locations of the bottomside radio window and topside enhanced radar echoes are consistent with the expected position determined by ray tracing performed using the observed plasma densities.

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Section: Experiments and Datamentioning

confidence: 99%

Angular dependence of pump-induced bottomside and topside ionospheric plasma turbulence at EISCAT

et al. 2011

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“…The EISCAT HF heating facility (Rietveld et al, 1993) located near Tromsø in Northern Norway (geographical coordinates 69.6 • N, 19.2 • E; magnetic dip angle I =78 • ) was used to perturb the ionosphere in the high-latitude F-region. The heating facility was operating at 4040 kHz, in O-mode polarization, with a modulation cycle of 2 min on/2 min off.…”

Section: Experimental Arrangementmentioning

confidence: 99%

Phenomena induced by powerful HF pumping towards magnetic zenith with a frequency near the F-region critical frequency and the third electron gyro harmonic frequency

Blagoveshchenskaya

Carlson²,

Kornienko

et al. 2009

Ann. Geophys.

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Abstract. Multi-instrument observational data from an experiment on 13 October 2006 at the EISCAT/HEATING facility at Tromsø, Norway are analysed. The experiment was carried out in the evening hours when the electron density in the F-region dropped, and the HF pump frequency f H was near and then above the critical frequency of the F2 layer. The distinctive feature of this experiment is that the pump frequency was just below the third electron gyro harmonic frequency, while both the HF pump beam and UHF radar beam were directed towards the magnetic zenith (MZ). The HF pump-induced phenomena were diagnosed with several instruments: the bi-static HF radio scatter on the LondonTromsø-St. Petersburg path, the CUTLASS radar in Hankasalmi (Finland), the European Incoherent Scatter (EIS-CAT) UHF radar at Tromsø and the Tromsø ionosonde (dynasonde). The results show thermal electron excitation of the HF-induced striations seen simultaneously from HF bi-static scatter and CUTLASS radar observations, accompanied by increases of electron temperature when the heater frequency was near and then above the critical frequency of the F2 layer by up to 0.4 MHz. An increase of the electron density up to 25% accompanied by strong HF-induced electron heating was observed, only when the heater frequency was near the critical frequency and just below the third electron gyro harmonic frequency. It is concluded that the combined effect of upper hybrid resonance and gyro resonance at the same altitude gives rise to strong electron heating, the excitation of Correspondence to: N. F. Blagoveshchenskaya (nataly@aari.nw.ru) striations, HF ray trapping and extension of HF waves to altitudes where they can excite Langmuir turbulence and fluxes of electrons accelerated to energies that produce ionization.

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“…The experiments reported here were conducted by using the EISCAT HF heating facility [Rietveld et al, 1993] To facilitate the interpretation of the Doppler measurements, we used data from the IMAGE magnetometer network [Liihr et al, 1998]. The locations of the IMAGE magnetometers are depicted in Figure 1.…”

Section: Usedmentioning

confidence: 99%

Ionospheric HF pump wave triggering of local auroral activation

Blagoveshchenskaya¹,

Kornienko²,

Борисова³

et al. 2001

J. Geophys. Res.

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Abstract. Experimental results from ionospheric HF pumping experiments in the nightside auroral E region above Troms0 are reported. We found intriguing evidence that a modification of the ionosphere-magnetosphere coupling, due to the effects of powerful HF waves beamed into an auroral sporadic E layer, can lead to a local intensification of the auroral activity. Summarizing multi-instrument observations during two consecutive nights, one can distinguish the following peculiarities related to this auroral activation: a modification of the auroral arc and its breakup above Troms0, local changes in the horizontal currents above Troms0, a burst-like increase of the electron density and temperature, a large increase in the ion temperature in a wide altitude range and in the north-south component of the electric field, distinctive features in dynamic HF radio scatter Doppler spectra, pumpinduced electron precipitation, and substorm activation exactly above Troms0. We discuss the modification of the ionosphere-magnetosphere coupling in terms of the excitation of a turbulent Alfv•n boundary layer between the base of the ionosphere (• 100 km) and the level of sharp increase of the Alfv•n velocity (at heights up to one Earth radius), and the formation of a local magnetospheric current system. The results suggest that a possible triggering of local auroral activation requires specific geophysical conditions.

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Introduction to ionospheric heating at Tromsø—I. Experimental overview

Cited by 227 publications

References 62 publications

Angular dependence of pump-induced bottomside and topside ionospheric plasma turbulence at EISCAT

Angular dependence of pump-induced bottomside and topside ionospheric plasma turbulence at EISCAT

Phenomena induced by powerful HF pumping towards magnetic zenith with a frequency near the F-region critical frequency and the third electron gyro harmonic frequency

Ionospheric HF pump wave triggering of local auroral activation

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