Sounding rocket study of two sequential auroral poleward boundary intensifications

Mella, M. R.; Lynch, K. A.; Hampton, D. L.; Dahlgren, Hanna; Kintner, P. M.; Lessard, M.; Lummerzheim, D.; Lundberg, Erik; Nicolls, M. J.; Stenbaek‐Nielsen, H. C.

doi:10.1029/2011ja016428

Cited by 17 publications

(25 citation statements)

References 47 publications

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“…Electron data from the Physics of the Auroral Zone Electrons II rocket showed a case of a so-called inverted-V structure with plasma sheet electrons accelerated to an energy of several keV, during which field-aligned bursts of cold electrons with a spread in energy from a few tens of eV up to the inverted-V energy, were seen superimposed [Semeter et al, 2001]. A similar event was observed with instruments on the Auroral Turbulence 2 rocket [Ivchenko et al, 1999], and the Cascades-2 rocket, where Alfvénic processes were found superimposed on a quasi-static acceleration signature [Mella et al, 2011;Lynch et al, 2012]. Time-dispersed field-aligned electron bursts by Alfvén waves have also been seen in an inverted-V structure with instruments on the Reimei satellite [Asamura et al, 2009], where the low-energy populations were found to drive instabilities giving rise to vortical auroral forms.…”

Section: Introductionsupporting

confidence: 53%

“…A similar event was observed with instruments on the Auroral Turbulence 2 rocket [Ivchenko et al, 1999], and the Cascades-2 rocket, where Alfvénic processes were found superimposed on a quasi-static acceleration signature [Mella et al, 2011;Lynch et al, 2012]. Time-dispersed field-aligned electron bursts by Alfvén waves have also been seen in an inverted-V structure with instruments on the Reimei satellite [Asamura et al, 2009], where the low-energy populations were found to drive instabilities giving rise to vortical auroral forms.…”

Section: Introductionmentioning

confidence: 53%

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Coexisting structures from high‐ and low‐energy precipitation in fine‐scale aurora

Dahlgren

Lanchester

Ivchenko

2015

Geophysical Research Letters

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High‐resolution multimonochromatic measurements of auroral emissions have revealed the first optical evidence of coexisting small‐scale auroral features resulting from separate high‐ and low‐energy populations of precipitating electrons on the same field line. The features exhibit completely separate motion and morphology. From emission ratios and ion chemistry modeling, the average energy and energy flux of the precipitation is estimated. The high‐energy precipitation is found to form large pulsating patches of 0.1 Hz with a 3 Hz modulation, and nonpulsating coexisting discrete auroral filaments. The low‐energy precipitation is observed simultaneously on the same field line as discrete filaments with no pulsation. The simultaneous structures do not interact, and they drift with different speeds in different directions. We suggest that the high‐ and low‐energy electron populations are accelerated by separate mechanisms, at different distances from Earth. The small‐scale structures could be caused by local instabilities above the ionosphere.

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Section: Introductionsupporting

confidence: 53%

Section: Introductionmentioning

confidence: 53%

Coexisting structures from high‐ and low‐energy precipitation in fine‐scale aurora

Dahlgren

Lanchester

Ivchenko

2015

Geophysical Research Letters

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“…For example, Figure 1 shows data from the recent NASA Cascades2 auroral sounding rocket mission. 10 Panel (a) shows observations of the floating potential of an ionospheric detector spacecraft from the mission versus time. The blue line gives the inferred floating potential of electric field-measuring probespheres using the thermal current balance model in Eq.…”

Section: Introductionmentioning

confidence: 99%

A laboratory experiment to examine the effect of auroral beams on spacecraft charging in the ionosphere

et al. 2011

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A 2.54 cm diameter conducting electrically isolated Copper sphere is suspended in a low density (10 4 cm À3 ), low temperature (T e ¼ 0.5 eV) Argon plasma, which mimics a spacecraft in an ionospheric plasma. An electron beam with current density of approximately 10 À10 A=cm 2 and beam spot of 10.2 cm diameter, which mimics an auroral electron beam, is fired at the sphere while varying the beam energy from 100 eV to 2 keV. The plasma potential in the sheath around the sphere is measured using an emissive probe as the electron beam energy is varied. To observe the effects of the electron beam, the experimental sheath potential profiles are compared to a model of the plasma potential around a spherically symmetric charge distribution in the absence of electron beams. Comparison between the experimental data and the model shows that the sphere is less negative than the model predicts by up to half a volt for beam energies that produce high secondary electron emission from the surface of the sphere. It is shown that this secondary emission can account for changes in potential of spacecraft in the ionosphere as they pass through auroral beams and thus helps to improve interpretations of ionospheric thermal ion distributions.

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“…Red-line aurora is particularly sensitive to low-energy precipitation [Shepherd et al, 1980] and has a relatively long lifetime, approximately 110 s at F region altitudes [Solomon et al, 1988;Semeter, 2003]. The red-line auroral emission profile is a well-documented feature [Solomon, 1988;Semeter, 2003;Mella et al, 2011;Link and Cogger, 1988]. It is characterized by an extended altitude due to the abundance of excited atomic oxygen in the F region ionosphere, and there exists a broad range of altitudes (150 to upward of 400 km) over which red-line aurora can exist.…”

Section: Introductionmentioning

confidence: 99%

Identifying the 630 nm auroral arc emission height: A comparison of the triangulation, FAC profile, and electron density methods

et al. 2017

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We present a comprehensive survey of 630 nm (red‐line) emission discrete auroral arcs using the newly deployed Redline Emission Geospace Observatory. In this study we discuss the need for observations of 630 nm aurora and issues with the large‐altitude range of the red‐line aurora. We compare field‐aligned currents (FACs) measured by the Swarm constellation of satellites with the location of 10 red‐line (630 nm) auroral arcs observed by all‐sky imagers (ASIs) and find that a characteristic emission height of 200 km applied to the ASI maps gives optimal agreement between the two observations. We also compare the new FAC method against the traditional triangulation method using pairs of all‐sky imagers (ASIs), and against electron density profiles obtained from the Resolute Bay Incoherent Scatter Radar‐Canadian radar, both of which are consistent with a characteristic emission height of 200 km.

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Sounding rocket study of two sequential auroral poleward boundary intensifications

Cited by 17 publications

References 47 publications

Coexisting structures from high‐ and low‐energy precipitation in fine‐scale aurora

Coexisting structures from high‐ and low‐energy precipitation in fine‐scale aurora

A laboratory experiment to examine the effect of auroral beams on spacecraft charging in the ionosphere

Identifying the 630 nm auroral arc emission height: A comparison of the triangulation, FAC profile, and electron density methods

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