F-Layer Ionization Patches in the Polar Cap.
Ground based optical and digital ionosonde measurements were conducted at Thule, Greenland, to measure ionospheric structure and dynamics in the nighttime polar cap F-layer. These observations showed the existence of large scale (800-1000 km) plasma patches drifting in the anti-sunward direction dur...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1983
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| Subjects: | |
| Online Access: | http://www.dtic.mil/docs/citations/ADA138633 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA138633 |
| Summary: | Ground based optical and digital ionosonde measurements were conducted at Thule, Greenland, to measure ionospheric structure and dynamics in the nighttime polar cap F-layer. These observations showed the existence of large scale (800-1000 km) plasma patches drifting in the anti-sunward direction during a moderately disturbed (Kp 4) period. Simultaneous Dynamics Explorer (DE-2) Low Altitude Plasma Instrument (LAPI) measurements show that these patches, with peak densities of approx. = 1000000 el 1/cm 3, are not locally produced by structured particle precipitation. The LAPI measurements show a uniform precipitation of polar-rain electrons over the polar cap. The combined measurements provide a comprehensive description of patch structure and dynamics. They are produced near or equatorward of the dayside auroral zone, and convect across the polar cap in the anti-sunward direction. As gradients within the large scale, drifting patches are subject to structuring by convective instabilities. The resulting irregularity distribution within the patches is mapped using uhf scintillation and spaced-receiver measurements. (Author) |
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