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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Quasi-periodic ripples in the heliosphere at 1 AU and beyond
AU - Birch, M.J.
AU - Hargreaves, J.K.
PY - 2021/1/1
Y1 - 2021/1/1
N2 - This study extends the investigation of the ripples in the solar wind and the interplanetary magnetic field at L1 reported by Birch and Hargreaves (2020) to cover heliospheric distances from 1 to 40 AU, using data from the Voyager 2, Ulysses, Juno, Cassini, Themis and Apollo-12 spacecraft. The ripples were extracted from the source data using a bandpass filter which reduces the noise component of the source data while removing long-term trends. The ripples were found to propagate throughout the heliosphere with an average periodicity of 26 min, without significant attenuation relative to the background. They also permeated within the magnetospheres of Earth, Jupiter and Saturn with an average periodicity of 25 min, though with some attenuation relative to the solar wind, especially in the case of Jupiter. Within the planetary magnetospheres, the ripples were suppressed by the intense fields in close proximity to each planet, and though the distance varied at which this cutoff occurred, the flux density was very similar in all three cases.
AB - This study extends the investigation of the ripples in the solar wind and the interplanetary magnetic field at L1 reported by Birch and Hargreaves (2020) to cover heliospheric distances from 1 to 40 AU, using data from the Voyager 2, Ulysses, Juno, Cassini, Themis and Apollo-12 spacecraft. The ripples were extracted from the source data using a bandpass filter which reduces the noise component of the source data while removing long-term trends. The ripples were found to propagate throughout the heliosphere with an average periodicity of 26 min, without significant attenuation relative to the background. They also permeated within the magnetospheres of Earth, Jupiter and Saturn with an average periodicity of 25 min, though with some attenuation relative to the solar wind, especially in the case of Jupiter. Within the planetary magnetospheres, the ripples were suppressed by the intense fields in close proximity to each planet, and though the distance varied at which this cutoff occurred, the flux density was very similar in all three cases.
KW - Geomagnetosphere
KW - Interplanetary magnetic field
KW - Jovian magnetosphere
KW - Quasi-periodic ripples
KW - Saturnian magnetosphere
KW - Solar wind
KW - Bandpass filters
KW - Interplanetary flight
KW - Magnetosphere
KW - Close proximity
KW - Flux densities
KW - Intense field
KW - Interplanetary magnetic fields
KW - Long-term trend
KW - Noise components
KW - Planetary magnetosphere
KW - Quasi-periodic
KW - Interplanetary spacecraft
U2 - 10.1016/j.asr.2020.08.030
DO - 10.1016/j.asr.2020.08.030
M3 - Journal article
VL - 67
SP - 678
EP - 699
JO - Advances in Space Research
JF - Advances in Space Research
SN - 0273-1177
IS - 1
ER -