The E-region Rocket/Radar Instability Study (ERRRIS): scientific objectives and campaign overview

Pfaff, R. F.; Sahr, John D.; Providakes, J.; Schwarz, Wolfgang; Farley, D. T.; Kintner, P. M.; Häggström, Ingemar; Hedberg, Å.; Opgenoorth, H. J.; Holmgren, Gunnar; McNamara, A. G.; Wallis, D. D.; Whalen, B. A.; Yau, A. W.; Watanabe, Shigeto; Creutzberg, F.; Williams, P. J. S.; Nielsen, E.; Schlegel, K.; Robinson, T. R.

doi:10.1016/0021-9169(92)90116-3

Cited by 27 publications

(17 citation statements)

References 29 publications

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“…4, the increase in T e is expected to be minute, but for the somewhat larger down-leg fields, E 0 ≈60-70 mV/m, nontrivial enhancements of T e are anticipated, but not observed for the present conditions. The wave propagation velocities, for instance, as found by Iranpour et al (1997), Krane et al (2000) and Dyrud et al (2006) are best explained by an electron temperature of approximately 400 K. Also other reports (Pfaff et al, 1992) noted the lack of electron temperature enhancements for conditions similar to ours. A previous study (Dyrud et al, 2006) attempted to explain the low electron temperatures by thermal conduction to the colder regions below the enhanced wave activity, but used too low numerical values for the electron energy loss per collision, by taking this energy loss to be at most an order of magnitude larger than for inelastic collisions.…”

Section: Numerical Simulationssupporting

confidence: 85%

Structure functions and intermittency in ionospheric plasma turbulence

Dyrud

Krane

Oppenheim³

et al. 2008

Nonlin. Processes Geophys.

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Abstract. Low frequency electrostatic turbulence in the ionospheric E-region is studied by means of numerical and experimental methods. We use the structure functions of the electrostatic potential as a diagnostics of the fluctuations. We demonstrate the inherently intermittent nature of the low level turbulence in the collisional ionospheric plasma by using results for the space-time varying electrostatic potential from two dimensional numerical simulations. An instrumented rocket can not directly detect the one-point potential variation, and most measurements rely on records of potential differences between two probes. With reference to the space observations we demonstrate that the results obtained by potential difference measurements can differ significantly from the one-point results. It was found, in particular, that the intermittency signatures become much weaker, when the proper rocket-probe configuration is implemented. We analyze also signals from an actual ionospheric rocket experiment, and find a reasonably good agreement with the appropriate simulation results, demonstrating again that rocket data, obtained as those analyzed here, are unlikely to give an adequate representation of intermittent features of the low frequency ionospheric plasma turbulence for the given conditions.

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Section: Numerical Simulationssupporting

confidence: 85%

Structure functions and intermittency in ionospheric plasma turbulence

Dyrud

Krane

Oppenheim³

et al. 2008

Nonlin. Processes Geophys.

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“…The STARE radar measurements were made in the same flux tube as EISCAT, as determined by the International Geomagnetic Reference Field (IGRF) model. The time resolution of the EISCAT observations was 180 s. The joint radar measurements used in this paper were obtained during the E Region Rocket/Radar Instability Study (ERRRIS) campaign[ Williams et al , 1990; Pfaff et al , 1992].…”

Section: Methodsmentioning

confidence: 99%

VHF coherent radar signals from the E region ionosphere and the relationship to electron drift velocity and ion acoustic velocity

Nielsen

Pozo

Williams³

2002

J. Geophys. Res.

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[1] The Scandinavian Twin Auroral Radar Experiment (STARE) coherent radar system measures the Doppler shifts caused by $1 m plasma waves in the high-latitude E region ionosphere. These Doppler velocities are here related to the electron drift velocity and ion acoustic velocity derived from measurements with the incoherent radar system European Incoherent Scatter (EISCAT). The Doppler velocity is limited in magnitude to near the ion acoustic velocity in the plasma. For large flow angles q, i.e., the angle between the radar line of sight and the electron drift velocity, the Doppler shifts are equal to the component of the electron drift velocity on the line of sight. For q $ 40°the Doppler velocity is equal to the ion acoustic velocity at 105-km altitude, and for decreasing flow angle the Doppler velocity increases. For 0°< q < 60°the variation with flow angle can be described as cos a q, where the a decreases from 0.8 to 0.2 with an increase in drift speed from $400 to 1600 ms À1 . The ratio of the line-of-sight velocity for q $ 0°to the ion acoustic velocity decreases from 1.2 at low velocities to 1.05 at large velocities. The systematic variations of the Doppler shifts with drift speed and flow angle make it possible, in principle, to recover the electron velocity from the coherent radar measurements. The observations are used to illustrate how well the recovery is possible in practice.

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“…Pfa et al, 1992), as if two distinct plasma regimes were present. If so, it would be surprising to ®nd that the wave heating rates would not change at least a little in the process.…”

Section: Discussionmentioning

confidence: 99%

On the usefulness of <i>E</i> region electron temperatures and lower <i>F</i> region ion temperatures for the extraction of thermospheric parameters: a case study

1999

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Using EISCAT data, we have studied the behavior of the i region electron temperature and of the lower p region ion temperature during a period that was particularly active geomagnetically. We have found that the i region electron temperatures responded quite predictably to the eective electric ®eld. For this reason, the i region electron temperature correlated well with the lower p region ion temperature. However, there were several instances during the period under study when the magnitude of the i region electron temperature response was much larger than expected from the ion temperature observations at higher altitudes. We discovered that these instances were related to very strong neutral winds in the 110±175 km altitude region. In one instance that was scrutinized in detail using i region ion drift measurement in conjunction with the temperature observations, we uncovered that, as suspected, the wind was moving in a direction closely matching that of the ions, strongly suggesting that ion drag was at work. In this particular instance the wind reached a magnitude of the order of 350 m/s at 115 km and of at least 750 m/s at 160 km altitude. Curiously enough, there was no indication of strong upper p region neutral winds at the time; this might have been because the event was uncovered around noon, at a time when, in the p region, the E Â B drift was strongly westward but the pressure gradients strongly northward in the p region. Our study indicates that both the lower p region ion temperatures and the i region electron temperatures can be used to extract useful geophysical parameters such as the neutral density (through a determination of ion-neutral collision frequencies) and Joule heating rates (through the direct connection that we have con®rmed exists between temperatures and the eective electric ®eld).

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The E-region Rocket/Radar Instability Study (ERRRIS): scientific objectives and campaign overview

Cited by 27 publications

References 29 publications

Structure functions and intermittency in ionospheric plasma turbulence

Structure functions and intermittency in ionospheric plasma turbulence

VHF coherent radar signals from the E region ionosphere and the relationship to electron drift velocity and ion acoustic velocity

On the usefulness of <i>E</i> region electron temperatures and lower <i>F</i> region ion temperatures for the extraction of thermospheric parameters: a case study

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The E-region Rocket/Radar Instability Study (ERRRIS): scientific objectives and campaign overview

Cited by 27 publications

References 29 publications

Structure functions and intermittency in ionospheric plasma turbulence

Structure functions and intermittency in ionospheric plasma turbulence

VHF coherent radar signals from the E region ionosphere and the relationship to electron drift velocity and ion acoustic velocity

On the usefulness of &lt;i&gt;E&lt;/i&gt; region electron temperatures and lower &lt;i&gt;F&lt;/i&gt; region ion temperatures for the extraction of thermospheric parameters: a case study

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On the usefulness of <i>E</i> region electron temperatures and lower <i>F</i> region ion temperatures for the extraction of thermospheric parameters: a case study