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Regular version of the site

Article

Short‐Fractional Hop Whistler Rate Observed by the Low‐Altitude Satellite DEMETER at the End of the Solar Cycle 23

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS. 2019. Vol. 124. No. 5. P. 3522-3531.
Shklyar D.

For the first time an evaluation of the whistler rate around the Earth is performed using results
from the neural network aboard the microsatellite DEMETER. It is shown that the rate of whistlers with low
dispersion calculated all around the Earth as a function of longitude vary between 1 and 6 s−1 during
nighttime (22.30 LT) and between 0.5 and 0.7 s−1 during daytime (10.30 LT). The whistler rate is
anticorrelated with the F10.7‐cm solar flux. A decrease by 25% of the solar flux corresponds to an increase of
62% (26%) of the averaged whistler rate calculated for the entire Earth during nighttime (daytime). Using this
averaged whistler rate, the global lightning rate is estimated to be of the order of 123 s−1 (27 s−1) during
nighttime (daytime). The main conclusion concerns the precipitation of the electrons in the radiation belt by
interaction with the whistlers. It is shown that the decrease of the lightning activity at solar minimum
(shown with the help of the Schumann resonances) is largely counterbalanced by the increase of the whistler
rates in the upper part of the ionosphere due to the decrease of the ionospheric absorption.