Experimental study of the relationship between the propagation distance and the polarization characteristics of whistlers

Abstract

Wideband (0‐8 kHz) measurements were performed for VLF whistlers at Moshiri (geomag. lat. 35°N) in Hokkaido in January, 1983 to investigate the relationship between polarization characteristics of whistlers and their propagation distance after the ionospheric transmission in the Earth‐ionosphere waveguide. the phase differences of the two signals of whistlers detected by orthogonal (E‐W and N‐S) loop antennas have been measured and the following results found: (1) the polarization of whistlers which penetrate the ionosphere close to the observing station is righthanded over a wide frequency range; and (2) some whistlers are found to have propagated over a distance of ∼1500 km. These whistlers exhibit a right‐handed polarization at some frequencies and a left‐handed polarization at other frequencies. However, the averaging of the observed polarizations over a wide frequency results in a nearly linear polarization; this agrees qualitatively with previous theoretical calculations by Crary.

Morphological characteristics and the polarization of plasmaspheric ELF hiss observed at Moshiri (L ∼ 1.6)

“…Figure 6b illustrates the phase difference in the frequency range from 1 to 1.5 kHz between the N-S and E-W magnetic field components of the hiss signals during the period indicated by an arrow at the bottom of Figure 6a. The definition of the polarization and phase difference has been described by Okada et al [1983], and when a circularly right-handed polarized whistler mode wave is incident to the station from the zenith, the output of the receiver connected to the E-W loop VEW lags by •r/2 in phase behind that connected to the N-S loop VNs, and we expect --90 ø in phase •b in Figure 6b. A right-handed polarization refers to the range from 0 ø to -180 ø, while a left-handed polarization should lie in a range from 0 ø to + 180 ø.…”