HF PUMP-INDUCED ELECTRON HEATING AND ARTIFICIAL AIRGLOW AT HIGH LATITUDES: ASPECT ANGLE DEPENDENCE
Large electron temperature increases (~3000 K) in the ionospheric F-region, produced by powerful HF wave injection, were measured using the EISCAT incoherent scatter radar near Tromsø, Norway, on 7 October 1999. Magnetic field-aligned measurements showed HF-initiated ion outflows reaching several hu...
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.488.6305 http://www.ursi.org/Proceedings/ProcGA02/papers/p1347.pdf |
Summary: | Large electron temperature increases (~3000 K) in the ionospheric F-region, produced by powerful HF wave injection, were measured using the EISCAT incoherent scatter radar near Tromsø, Norway, on 7 October 1999. Magnetic field-aligned measurements showed HF-initiated ion outflows reaching several hundred ms-1 at 580 km. When scanning the radar antenna from field-aligned (77.2º southward) to vertical, the strongest heating effects were always in the field-aligned position, irrespective of the HF beam direction which was varied. The imaged 630 nm HF-enhanced airglow also remained localized near field-aligned. Why the strongest heating effects occur for HF rays transmitted along the magnetic field is unclear. |
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