High‐altitude gas releases: transition from collisionless flow to diffusive flow in a nonuniform atmosphere

Bernhardt, P. A.

doi:10.1029/ja084ia08p04341

Cited by 47 publications

(20 citation statements)

References 18 publications

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“…Then T‐2 is almost as fast as the exhaust effusion, and we can neglect initial velocity of water molecules. Even if they have initial velocity of up to a few kilometers per second, it would not much influence the simulation because the typical travel distance of noncollisional flow, which precedes the onset of diffusion, would not exceed a few tens of kilometers under the present situation [ Bernhardt , 1979b].…”

Section: Model Of the Ionospheric Hole Formation By Taepodong‐2mentioning

confidence: 99%

Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array

Ozeki

Heki

2010

J. Geophys. Res.

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[1] A dense array of global positioning system (GPS) receivers is a useful tool to study ionospheric disturbances. Here we report observations by a Japanese GPS array of ionospheric holes, i.e., localized electron depletion. They were made by neutral molecules in exhaust plumes (e.g., water) of ballistic missiles from North Korea, Taepodong-1 and -2, launched on 31 August, 1998, and 5 April, 2009, respectively. Negative anomaly of electron density emerged ∼6 min after the launches in the middle of the Japan Sea, and extended eastward along the missile tracks. By comparing the numerical simulation of electron depletion and the observed change in ionospheric total electron content, we suggest that the exhaust plumes from the Taepodong-2 second stage effused up to ∼1.5 × 10 26 water molecules per second. The ionospheric hole signature was used to constrain the Taepodong-2 trajectory together with other information, e.g., coordinates of the launch pad, time and coordinates of the first stage splashdown, and height and time of the second stage passage over Japan. The Taepodong-2 is considered to have reached the ionospheric F region in ∼6 min, flown above northeastern Japan ∼7 min after the launch, and crashed to the Pacific Ocean without attaining the first astronautical velocity. The ionospheric hole in the 1998 Taepodong-1 launch was much less in size, but it is difficult to compare directly the thrusts of the two missiles due to uncertainty of the Taepodong-1 trajectory.Citation: Ozeki, M., and K. Heki (2010), Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array,

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Section: Model Of the Ionospheric Hole Formation By Taepodong‐2mentioning

confidence: 99%

Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array

Ozeki

Heki

2010

J. Geophys. Res.

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“…1 inset), the exhaust molecules should have had substantial backward velocity below that altitude. Here we neglected it because the typical travel distance of non-collisional flow, which precedes the onset of diffusion, does not exceed a few tens of kilometers under the present situation (Bernhardt, 1979b). We approximate continuous gas effusion from the rocket with a series of discrete point sources put along the track with a 10 second separation.…”

Section: Diffusion Of H 2 Omentioning

confidence: 99%

Ionospheric hole behind an ascending rocket observed with a dense GPS array

Furuya

Heki

2008

Earth Planet Sp

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An ascending liquid-fuel rocket is known to make a hole in the ionosphere, or localized electron depletion, by leaving behind large amounts of neutral molecules (e.g. water) in the exhaust plume. Such a hole was made by the January 24, 2006 launch of an H-IIA rocket from Tanegashima, Southwestern Japan, and here we report its observation with a dense array of Global Positioning System receivers as a sudden and temporary decrease of total electron content. The observed disturbances have been compared with a simple numerical model incorporating the water diffusion and chemical reactions in the ionosphere. The substantial vanishing of the ionosphere lasted more than one hour, suggesting its application as a window for ground-based radio astronomical observations at low frequencies.

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“…The collision frequency (ν in ) for ions moving through a neutral background has a strong dependence on the ion speed (V i ). An approximation to this dependence is given by Bernhardt [1979] as

where v n = (kT n /m n ) 1/2 = 715 m/s is the neutral sound speed, m n = 16 amu is the background neutral mass, and m i = 18 amu is the ion mass. For the atmospheric conditions in the SIMPLEX II experiment, this collision frequency at the altitude of the space shuttle ranges from 0.36 to 3.44 s −1 for ion speeds from 0 to 10.8 km/s.…”

Section: Theoretical Interpretationsmentioning

confidence: 99%

“…The collision frequency (n in ) for ions moving through a neutral background has a strong dependence on the ion speed (V i ). An approximation to this dependence is given by Bernhardt [1979] as…”

Section: Theoretical Interpretationsmentioning

confidence: 99%

Incoherent scatter measurements of ring‐ion beam distributions produced by space shuttle exhaust injections into the ionosphere

Bernhardt

Sulzer

2004

J. Geophys. Res.

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.[1] When the space shuttle Orbiting Maneuver Subsystem (OMS) engines burn in the ionosphere, two types of effects are produced. First, charge exchange between the exhaust molecules and the ambient O + -ions yields beams of high-speed molecular ions that can excite plasma turbulence. Second, the molecular ions eventually recombine with electrons to yield a plasma hole. The ion-beam interactions and the formation of artificial plasma holes in the ionosphere have been studied with ground-based, incoherent-scatter radars (ISRs) during the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) series of experiments. The SIMPLEX II experiment took place in late July 1999 during the STS-93 flight of the Space Shuttle Columbia. The Orbital Maneuver Subsystem (OMS) engines provided controlled ion injections over the incoherent scatter radar (ISR) facilities located at Arecibo, Puerto Rico to excite unusual radar signatures. After charge exchange between the exhaust and the ambient plasma, pickup ions were produced with velocities near 10 km/s using a ram-burn orientation of the OMS engines relative to the vehicle orbit vector. During the SIMPLEX II experiment, the ISR spectra of the exhaust-modified plasma were obtained for the first time. The formation of ring-ion beam distributions was determined from curve fitting to the radar spectra. These spectra show the presence of the nonthermal ion distributions and enhanced scatter from electrons for thermal ion distributions with elevated ion temperatures. Analysis of the ion distributions in the modified ionosphere indicates that they were unstable and may have quickly generated plasma waves that along with ion-neutral collisions changed the ionvelocity distributions. The observations show that the perpendicular ion speed was rapidly reduced from 10 km/s to about 1 km/s. These observations open up the possibility of conducting a new series of experiments studying ring-ion beam instabilities that occur naturally in the auroral-region ionosphere and artificially in the space shuttle exhaust where there is large relative motion between the ion and neutral species.

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High‐altitude gas releases: transition from collisionless flow to diffusive flow in a nonuniform atmosphere

Cited by 47 publications

References 18 publications

Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array

Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array

Ionospheric hole behind an ascending rocket observed with a dense GPS array

Incoherent scatter measurements of ring‐ion beam distributions produced by space shuttle exhaust injections into the ionosphere

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