Enhanced EISCAT UHF backscatter during high-energy auroral electron precipitation

• Published in: Annales Geophysicae
• Main Authors: Schlatter, Nicola M., Ivchenko, Nickolay, Sergienko, T, Gustavsson, Björn Johan, Brändström, B. U. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus 2013
• Subjects: VDP::Mathematics and natural science: 400::Physics: 430::Space and plasma physics: 437; VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430::Rom- og plasmafysikk: 437; EISCAT
• Online Access: https://hdl.handle.net/10037/6045; https://doi.org/10.5194/angeo-31-1681-2013

Natural enhancements in the backscattered power of incoherent scatter radars up to 5 orders of magnitudes above the thermal backscatter are sometimes observed at high latitudes. Recently observations of enhancements in the backscattered power including a feature at zero Doppler shift have been reported. These enhancements are limited in altitude to tens of kilometers. The zero Doppler shift feature has been interpreted as a signature of electron density cavitation. Enhanced plasma lines during these observations have also been reported. We report on the first EISCAT UHF observations of enhanced backscattered radar power including a zero Doppler shift feature. The enhancements originated from two distinct and intermittent layers at about 200 km altitude. The altitude extent of the enhancements, observed during auroral high-energy electron precipitation, was < 2 km.