The polarization of auroral radio emissions

S.G. Shepherd, J. LaBelle, M.L. Trimpi
Dartmouth College, Hinman Box 6127, Wilder Hall, Hanover, NH, 03755, USA

Abstract:

Ground level observations using two vertical loop antennas oriented at 90 to each other reveal the sense of polarization of several types of auroral radio emissions in the frequency range 30-5000 kHz. Auroral hiss is observed to be right elliptically polarized (RP) with respect to the local magnetic field, consistent with theoretical expectation for the whistler mode and with earlier measurements. Two less well-understood auroral emissions, are found to be left elliptically polarized (LP). This polarization is inconsistent with their generation in the X-mode as suggested by some theories.

AGU Index Terms: 6964 Radio wave propagation; 2407 Auroral ionosphere; 2471 Plasma waves and instabilities; 6984 Waves in plasma
Keywords/Free Terms: Ionosphere, Polarization, Radio waves, Auroral.

Geophysical Res. Ltrs. 97GL03160
Vol. 24 , No. 24 , p. 3161