First EISCAT measurement of electron-gas temperature in the arti®cially heated D-region ionosphere

• Main Authors: A. Kero, T. Boè Singer, P. Pollari, E. Turunen, M. Rietveld
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: EISCAT
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.431; http://www.ann-geophys.net/18/1210/2000/angeo-18-1210-2000.pdf

Abstract. The ionospheric electron gas can be heated arti®cially by a powerful radio wave. According to our modeling, the maximum e€ect of this heating occurs in the D-region where the electron temperature can increase by a factor of ten. Ionospheric plasma parameters such as Ne; Te and Ti are measured by EISCAT incoherent scatter radar on a routine basis. However, in the D-region the incoherent scatter echo is very weak because of the low electron density. Moreover, the incoherent scatter spectrum from the D-region is of Lorentzian shape which gives less information than the spectrum from the E- and F-regions. These make EISCAT measurements in the D-region di cult. A combined EISCAT VHF-radar and heating experiment was carried out in November 1998 with the aim to measure the electron temperature increase due to heating. In the experiment the heater was switched on/o € at 5 minute intervals and the integration time of the radar was chosen synchronously with the heating cycle. A systematic di€erence in the measured autocorrelation functions was found between heated and unheated periods. Key words: Ionosphere �active experiments; plasma temperature and density; wave propagation) 1