TWO RECENT kHz OUTER HELIOSPHERIC RADIO EMISSIONS

Abstract

17 We have examined instigating events at the Sun that may be responsible for two of the 18 most recent outer heliospheric kHz emissions detected by the University of Iowa plasma wave 19 detector on Voyager 1 starting at 2004.64 and 2006.39, respectively. These interplanetary events 20 have been followed outward from the Sun using plasma and cosmic ray data from Ulysses and 21 Voyagers 1 and 2. For both intervals of kHz emissions, events originating near the Sun that turn 22 out to be the most intense events in this 11-year solar cycle as observed by the plasma and 23 cosmic ray variations in the outer heliosphere, reach V1 and V2 which are near the heliospheric 24 termination shock at almost the same time that the two kHz radio emissions turn-on. These two 25 events which originate near the Sun about 2003.89 (the 2003 Halloween event) and at 2005.71, 26 are also unusual in that they develop solar wind ram pressure waves in the outer heliosphere with 27 maximum pressures ~6-8 times the average solar wind pressure when they reach the heliospheric 28 termination shock. We believe that this study suggests a possible new paradigm for the origin of 29 these latest kHz emissions. This new paradigm is different from the current one describing 30 earlier kHz events. It is related to the strength of these pressure waves in the outer heliosphere 31 and involves the arrival of these large pressure waves at the heliospheric termination shock rather 32 than the arrival of a shock at the heliopause as is the current paradigm. 33

Cite this paper

@inproceedings{Webber2009TWORK, title={TWO RECENT kHz OUTER HELIOSPHERIC RADIO EMISSIONS}, author={William R Webber and Devrie S. Intriligator}, year={2009} }