Ionization and expansion of barium clouds in the ionosphere

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA01552· OSTI ID:7061535

Ma, T Z; Schunk, R W ^[1]

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1. Utah State Univ., Logan (United States)

A three-dimensional time-dependent model was used to study the ionization and plasma expansion characteristics of barium clouds released in the ionosphere. Neutral gas clouds with a total mass of 1 kg were released with a spherical Gaussian density distribution. The subsequent photoionization by solar UV radiation and ion cloud expansion was modeled. The results from three simulations are presented: a cloud without a directional velocity; a cloud with an initial velocity of 5 km/s across the B field; and a cloud with initial velocity components of 2 km/s both along and across the B field. For the cloud without a directional velocity, the ionization occurs in a spherical volume. The resulting Ba[sup +] cloud expands along the B field and the Ba[sup +] density distribution becomes ellipsoidal from the inner to the outer parts of the Ba[sup +] cloud. The electrostatic snowplow effect associated with the expanding Ba[sup +] cloud creates a hole in the O[sup +] background at the center of the Ba[sup +] cloud and creates two O[sup +] density bumps on the two sides of the Ba[sup +] cloud. For the neutral gas release with an initial velocity across the B field, the resulting Ba[sup +] cloud begins with a cometlike density distribution. Eventually the Ba[sup +] cloud becomes sheetlike. There are two O[sup +] density enhanced regions and one O[sup +] density depletion region in the background ionosphere. For these two cases, although there are O[sup +] density depletions, there are no electron density (total plasma) depletions. When the neutral gas cloud has initial velocity components along and across the B field, the situation is different. The resulting Ba[sup +] cloud has a complicated density distribution. The Ba[sup +] snowplow effect creates an O[sup +] density hole on one side and an O[sup +] density bump on the other side of the Ba[sup +] cloud. There is a net plasma depletion on the side opposite to the Ba[sup +] cloud motion along the B field. 33 refs., 8 figs.

• OSTI ID: 7061535
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 98:A1; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
BARIUM
DISTRIBUTION
EARTH ATMOSPHERE
ELECTRON DENSITY
ELEMENTS
EXPANSION
IONIZATION
IONOSPHERE
METALS
NONMETALS
OXYGEN
PHOTOIONIZATION
PLANETARY IONOSPHERES
PLASMA EXPANSION
THREE-DIMENSIONAL CALCULATIONS