Incoherent scatter observations of an artificially modified ionosphere

Wand, R. H.; Mendillo, M.

doi:10.1029/ja089ia01p00203

Cited by 25 publications

(16 citation statements)

References 23 publications

(12 reference statements)

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“…Other Spacelab 2 burns over the Millstone Hill incoherent scatter radar showed similar enhanced backscatter above and below an ionospheric "hole" [Mendillo et al, 1987]. Similar radar signatures were recorded by the Millstone Hill incoherent scatter facility (42.6øN, 71.5øW) during the launch of an Atlas/Centaur rocket on September 20, 1979 [Wand and Mendillo, 1984]. The 440-MHz radar was 1780 km from the rocket exhaust trail when the observations were made.…”

mentioning

confidence: 54%

“…The theory developed here will apply to both space shuttle and Centaur rocket exhaust. The plasma in the exhaust plumes is taken to consist of molecular ions (predominantly H2 O+ with mass m m = 18 mp, where mp is proton mass), iono- Wand and Mendillo [1984]. The incoherent scatter is enhanced by factors of 1.2 above and below the location of the rocket plume.…”

Section: Examinationmentioning

confidence: 99%

“…Semeter et al [1996] suggest that the initial density reductions could be produced by displacement of the plasma by the expanding release clouds. Wand and Mendillo [1984] attribute the enhanced radar backscatter to the "snowplow effect" from the expanding exhaust gases that increase the electron density at the sides of the plume. Bernhardt et al [1995] suggest that the enhanced backscatter may be produced by phenomena in the plasma which only "appear" to be a buildup of electron density.…”

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confidence: 99%

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Incoherent scatter from space shuttle and rocket engine plumes in the ionosphere

Bernhardt¹,

Huba²,

Swartz³

et al. 1998

J. Geophys. Res.

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Abstract. Enhanced echoes from the 430 MHz radar at Arecibo were observed during burns of the space shuttle orbital maneuver subsystem (OMS) engines near 317 km altitude. Similar radar signatures of enhanced backscatter were also obtained by the Millstone Hill radar observing the plume of a Centaur engine burning in the ionosphere. A theoretical model of incoherent scatter is presented to explain the radar backscatter observations. The theory considers molecular ion beams generated in the exhaust plume as a result of charge exchange between the ambient O + ions and the high-speed exhaust molecules (primarily H20 ). The field-aligned gyromotion of the pickup ions affects the radio wave scattering from the random thermal fluctuations of electron density. Numerical calculations are carried out for plasmas modified by the space shuttle or Centaur engines, and reasonable agreement with observations is found for the total scattered power. Incoherent backscatter spectra respond to characteristics of the exhaust plume such as vector flow velocity, temperature, and composition. The nonequilibrium velocity distributions for the ions in the pickup ion plume are similar to the distributions found in strongly convecting auroral region ionospheres. The incoherent scatter from the plume ions can be used to validate techniques used to study naturally disturbed plasmas. The predictions of our radar scatter calculations will be tested in future experiments using the space shuttle OMS engines over incoherent scatter radars located at equatorial latitudes and midlatitudes.

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confidence: 54%

Section: Examinationmentioning

confidence: 99%

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confidence: 99%

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Incoherent scatter from space shuttle and rocket engine plumes in the ionosphere

Bernhardt¹,

Huba²,

Swartz³

et al. 1998

J. Geophys. Res.

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“…[12] The STIM background neutral atmosphere, along with the time-evolution of a bulge of water density resulting [Moore et al, 2006]: a region of photochemical equilibrium, wherein ion production/loss rates are balanced (tan), a diffusive regime dominated by transport processes (orange), and a heavy ion regime dominated by hydrocarbon and/or metallic ions (light blue). (b) Terrestrial profiles demonstrating the formation of an ''ionospheric hole'' in response to exhaust gases from the launch of NASA's HEAO-C satellite [Wand and Mendillo, 1984]. from a point-source release at Saturn, is shown in the left column of Figure 2.…”

Section: Resultsmentioning

confidence: 99%

Are plasma depletions in Saturn's ionosphere a signature of time‐dependent water input?

Moore¹,

Mendillo²

2007

Geophysical Research Letters

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Recent radio occultation measurements by the Cassini spacecraft reveal the presence of numerous “ionospheric holes”, or plasma depletions, in Saturn's upper atmosphere that cannot be explained with standard photochemical theory. The holes are remarkably similar in size and shape to artificially‐created depletions first observed in the terrestrial ionosphere during the 1970s. At Earth, such vertical structures are typically caused by the enhanced loss of electrons and ions resulting from the introduction of spacecraft exhaust products (e.g., H2O) into the atmosphere. Using a new model of Saturn's upper atmosphere, we show that a time‐variable influx of water into Saturn's ionosphere could explain the observed plasma depletions. The required influxes present a target to assess for the possible sources and consequences of water processes throughout the Saturnian system.

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“…Mendillo et al (1975) present beacon-satellite observations of TEC in the vicinity of the trajectory of the Skylab launch while Wand and Mendillo (1984) report Millstone Hill radar observations of the ionospheric e ects of the launch of HEAO-C. Neither of these daytime studies observed any persistent oscillations of the ionosphere following the creation of large-scale ionospheric holes by the launch-vehicle exhaust products at F-region heights.…”

Section: Persistent E Ects Of Arti®cial Ionospheric Perturbationmentioning

confidence: 99%

Mid-latitude ionospheric perturbation associated with the Spacelab-2 plasma depletion experiment at Millstone Hill

Foster

Holt

Lanzerotti³

2000

Ann. Geophys.

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Abstract. Elevation scans across geomagnetic mid latitudes by the incoherent scatter radar at Millstone Hill captured the ionospheric response to the ®ring of the Space Shuttle Challenger OMS thrusters near the peak of the F layer on July 30, 1985. Details of the excitation of airglow and the formation of an ionospheric hole during this event have been reported in an earlier paper by Mendillo et al.. The depletion (factor $2) near the 320 km Shuttle orbital altitude persisted for $35 min and then recovered to near normal levels, while at 265 km the density was reduced by a factor of $6; this signi®cant reduction in the bottomside F-region density persisted for more than 3 hours. Total electron content in the vicinity of the hole was reduced by more than a factor of 2, and an oscillation of the F-region densities with 40-min period ensued and persisted for several hours. Plasma vertical Doppler velocity varied quasiperiodically with a $80-min period, while magnetic ®eld variations observed on the ®eld line through the Shuttleburn position exhibited a similar $80-min periodicity. An interval of magnetic ®eld variations at hydromagnetic frequencies ($95 s period) accompanied the ionospheric perturbations on this ®eld line. Radar observations revealed a downward phase progression of the 40-min period density enhancements of A1.12°km A1 , corresponding to a 320-km vertical wavelength. An auroral-latitude geomagnetic disturbance began near the time of the Spacelab-2 experiment and was associated with the imposition of a strong southward IMF Bz across the magnetosphere. This created an additional complication in the interpretation of the active ionospheric experiment. It cannot be determined uniquely whether the ionospheric oscillations, which followed the Spacelab-2 experiment, were related to the active experiment or were the result of a propagating ionospheric disturbance (TID) launched by the enhanced auroral activity. The most reasonable conclusion is that the ionospheric oscillations were a result of the coincident geomagnetic disturbance. The pronounced depletion of the bottomside ionosphere, however, accentuated the oscillatory behavior during the interval following the Shuttle OMS burn.

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Incoherent scatter observations of an artificially modified ionosphere

Cited by 25 publications

References 23 publications

Incoherent scatter from space shuttle and rocket engine plumes in the ionosphere

Incoherent scatter from space shuttle and rocket engine plumes in the ionosphere

Are plasma depletions in Saturn's ionosphere a signature of time‐dependent water input?

Mid-latitude ionospheric perturbation associated with the Spacelab-2 plasma depletion experiment at Millstone Hill

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