Chemical releases in the ionosphere

Davis, T. N.

doi:10.1088/0034-4885/42/9/003

Cited by 26 publications

(32 citation statements)

References 84 publications

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“…The reason why the plumes are lumpy is not known. (Other E × B ‐drifting dense plasmas are also observed to be structured [e.g., Davis , 1979; Simons et al , 1981]. ) Four suggestions as to the origin of the lumpiness of the drainage‐plume plasma are discussed in the following four paragraphs.…”

Section: Discussionmentioning

confidence: 99%

A statistical look at plasmaspheric drainage plumes

2008

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[1] The properties of plasmaspheric drainage plumes are examined using cold-plasma measurements in geosynchronous orbit. During high-speed stream-driven storms, 210 plume crossings are collected and statistically analyzed. Plumes that persist for 4 days are common, which was the duration of our search. Plumes weaken with age, becoming narrower in local time with plasma that becomes less dense. Cold-plasma flow velocities are sunward in the plumes, with flow speeds decreasing as the storms progress. Plumes transfer typically 2 Â 10 26 ions/sec (1.2 ton/hr of protons) when they are young, and the rate of transport decreases with plume age. A total of approximately 2 Â 10 31 ions (34 tons of protons) are transported via plumes in the life of a storm. About half of the outer plasmasphere is drained in the first 20 hours of a storm. Large density fluctuations in the plumes indicate that the drainage plumes are lumpy, and large velocity fluctuations of the plasma flow indicate that the drainage plumes may be turbulent. Because of their persistence, drainage plumes are anticipated to be a regular feature of any ongoing geomagnetic storm.

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Section: Discussionmentioning

confidence: 99%

A statistical look at plasmaspheric drainage plumes

2008

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“…(2) and (3) assume that at the time 0 t = the atomic population density at the ground level is 0 N , and there are no atoms at the excited level. 0 N has a homogeneous spatial distribution, which satisfies selfsimilar solution [4].…”

Section: The Model Of Absorption and Scattering Of The Sunlight Wmentioning

confidence: 99%

“…Therefore, the full radiation from all spatial area is shifted to the "blue" spectral wing. With further increase in α (velocity of expansion), the "blue" spectral shift decreases, also the line shape becomes symmetric (curves [3][4][5], that is caused again by the bleaching of the medium at 0 τ >> α for the scattered radiation [1,2]. …”

Section: B Scattered Radiationmentioning

confidence: 99%

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Scattering of resonant radiation in an expanding sphere

Shaparev

2012

2012 International Conference on Optoelectronics and Microelectronics

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The radiative transfer in a freely expanding gaseous sphere, illuminated by external radiation, has been studied numerically. The absorption coefficient, spectral and spatial characteristics of the absorbed and scattered radiation, the radial dependences of excited atomic concentration have been determined, the influence of the optical thickness and the atomic radial expansion velocity on them have been investigated.

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“…Obtaining the neutral wind measurement in the E and F region that are required to understand the strongly coupled system in those regions has been a challenge since the early days of ionospheric physics. A variety of metal vapor releases have been used in sounding rocket experiments during the last five decades as tracers of the neutral or ion motions in the thermosphere and ionosphere, including sodium, lithium, barium, and strontium (see, Davis, 1979;Larsen, 2002, for comprehensive reviews). Some of the earliest releases involved the use of lithium vapor as a neutral tracer (e.g., Derblom et al, 1966).…”

Section: Introductionmentioning

confidence: 99%

Rocket-borne Lithium ejection system for neutral wind measurement

Habu¹,

Yamamoto²,

Watanabe³

et al. 2013

An Introduction to Space Instrumentation

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Chemical tracer releases represent the most widely used technique for in situ neutral wind measurements in the thermosphere/ionosphere region. Different chemicals have been used for this purpose, but lithium releases in particular provide some unique capabilities due to the strong resonant emissions that are produced when lithium is illuminated by sunlight. The majority of the lithium releases from sounding rockets were carried out in the 1960's and 1970's, but there has been recent renewed interest in the use of lithium vapor releases to extend neutral wind measurements into the F region and for daytime wind profile measurements in the E region. The rocketborne Lithium Ejection System (LES) is a chemical release device that has been developed for the Japanese space research program. Since lithium vapor acts as a neutral tracer, the winds are obtained by tracking the motion of the clouds or trails optically from the ground using the bright red emission that is characteristic of the chemical. Lithium is a solid at room temperature, so that a gas release requires rapid vaporization of the metal to make the cloud at the intended altitude. The release canister is designed to produce a high-heat chemical reaction without gaseous products. Appropriate mixtures of thermite are employed as the heat source. In early experiments, lithium pellets were mixed directly into the thermite. However, since lithium is an active chemical, the use of lithium-thermite mixtures creates potential hazards when used in a rocket-borne device. Moreover, the pyrotechnic devices used to ignite the thermite also have to be considered in the payload canister design to assure that the safety standards for sounding rockets are satisfied. The design of the LES, described in this paper, was based on the safety requirements and the reliability in storing and handling of the materials. The LES design is also flexible in that the lithium tracer material can be replaced with other chemicals without difficulties. This paper introduces the design of the LES and the method for controlling the thermite burn.

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Chemical releases in the ionosphere

Cited by 26 publications

References 84 publications

A statistical look at plasmaspheric drainage plumes

A statistical look at plasmaspheric drainage plumes

Scattering of resonant radiation in an expanding sphere

Rocket-borne Lithium ejection system for neutral wind measurement

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