EISCAT Tri-Static Observation of Polar Mesosphere Winter Echoes and what will be better with EISCAT_3D
Swedish Institute of Space Physics
Polar Mesosphere Winter Echoes (PMWE) are strong coherent signals from 50-80 km altitudes observed by VHF radars in the equinox and winter seasons. PMWE are not everyday phenomena since in order for the radars to see them the lower ionosphere has to be additionally ionised e.g. by solar protons or energetic electrons of magnetospheric origin. Thus PMWE observations with the EISCAT VHF radar (unlike with continuously operated MST radars) have not been frequent and were mainly limited to the mono-static configuration. During the solar proton event on 8 January 2014 the vertically pointed EISCAT 224 MHz radar in TromsÃ¸ ran the manda experiment and observed patches of PMWE at about 70 km. The EISCAT remote receivers in Kiruna and Sodankyla also detected an enhanced signal from the same altitude. The spectra of the strongest PMWE observed from three sites were analysed and compared with IS spectra from the background plasma. The possible relation of the observed PMWE to gravity waves and wind shear will be discussed. I also will talk about new capabilities of EISCAT_3D for PMWE measurements.
Created 2017-01-09 14:41:56 by Mats HolmstrÃ¶m Last changed 2017-06-19 13:10:55 by Mats HolmstrÃ¶m