Enhanced EISCAT UHF backscatter during high-energy auroral electron precipitation
N. M. Schlatter1,N. Ivchenko1,T. Sergienko2,B. Gustavsson3,and B. U. E. Brändström2N. M. Schlatter et al. N. M. Schlatter1,N. Ivchenko1,T. Sergienko2,B. Gustavsson3,and B. U. E. Brändström2
1School of Electrical Engineering, Royal Institute of Technology, Teknikringen 31, 100 44 Stockholm, Sweden
2Institute for Space Physics, Rymdcampus 1, 981 92 Kiruna, Sweden
3EISCAT scientific association, Rymdcampus 1, 981 92 Kiruna, Sweden. Now at: Department of Physics and Technology, University of Tromsø, 9037 Tromsø, Norway
1School of Electrical Engineering, Royal Institute of Technology, Teknikringen 31, 100 44 Stockholm, Sweden
2Institute for Space Physics, Rymdcampus 1, 981 92 Kiruna, Sweden
3EISCAT scientific association, Rymdcampus 1, 981 92 Kiruna, Sweden. Now at: Department of Physics and Technology, University of Tromsø, 9037 Tromsø, Norway
Received: 21 Jan 2013 – Revised: 11 Jul 2013 – Accepted: 03 Sep 2013 – Published: 09 Oct 2013
Abstract. 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.
