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- W2070694799 endingPage "4375" @default.
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- W2070694799 abstract "High‐resolution measurements by the Freja spacecraft of broadband extremely low frequency (BB‐ELF) emission from dc up to the lower hybrid frequency (a few kHz) are reported from regions of transverse ion acceleration (TAI) and broad‐energy suprathermal electron bursts (STEB) occuring in the topside ionospheric auroral regions. A gradual transition of the broadband emission occurs near the local O + cyclotron frequency (ƒO + ≈ 25 Hz) from predominantly electromagnetic below this frequency to mostly electrostatic above this frequency. The emission below 200 Hz often reach amplitudes up to several hundred mV/m and density perturbations (δ n / n ) of tens of %. An improved analysis technique is presented, based on the quantity |δ E /(δ n / n )| versus frequency and applied to the Freja plasma wave measurements. The method can be used to infer the dispersion relation for the measured emission as well as give estimates of the thermal plasma temperatures. The BB‐ELF emission is found to consist partly of plasma waves with an ion Boltzmann response, which is interpreted as originating from the so‐called slow ion acoustic wave mode (SIA). This emission is associated with large bulk ion (O + ) temperatures of up to 30 eV and low electron temperatures (1–2 eV) and therefore occurs during conditions when T e / T i ≪ 1. The BB‐ELF emissions also contain other wave mode components, which are not equally easy to identify, even though it is reasonably certain that ion acoustic/cyclotron waves are measured. The ion Boltzmann component is characterized by a dominantly perpendicular polarization with respect to the Earth's magnetic field direction and a small magnetic component with amplitudes around 0.1–1 nT. The ion Boltzmann component dominates the lower‐frequency part (30–400 Hz) of the BB‐ELF emissions. The BB‐ELF emission have often an enhanced spectral power when certain waveform signatures, interpreted as solitary kinetic Alfvén waves (SKAW), or when large‐amplitude electric fields, possibly related to black aurora, are encountered in regions often associated with large‐scale auroral density depletions. A scenario where the SKAW provides the original free energy and via the BB‐ELF emission causes intense transverse ion heating (TAI) is suggested." @default.
- W2070694799 created "2016-06-24" @default.
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- W2070694799 date "1998-03-01" @default.
- W2070694799 modified "2023-10-14" @default.
- W2070694799 title "Broadband ELF plasma emission during auroral energization: 1. Slow ion acoustic waves" @default.
- W2070694799 cites W1651765052 @default.
- W2070694799 cites W1663332251 @default.
- W2070694799 cites W1965985623 @default.
- W2070694799 cites W1967105797 @default.
- W2070694799 cites W1967135983 @default.
- W2070694799 cites W1968240903 @default.
- W2070694799 cites W1972970416 @default.
- W2070694799 cites W1975168805 @default.
- W2070694799 cites W1976490878 @default.
- W2070694799 cites W1976671848 @default.
- W2070694799 cites W1979195542 @default.
- W2070694799 cites W1980158874 @default.
- W2070694799 cites W1980769578 @default.
- W2070694799 cites W1982437740 @default.
- W2070694799 cites W1983511256 @default.
- W2070694799 cites W1985409965 @default.
- W2070694799 cites W1986186714 @default.
- W2070694799 cites W1986686248 @default.
- W2070694799 cites W1990443493 @default.
- W2070694799 cites W1990826718 @default.
- W2070694799 cites W1991181517 @default.
- W2070694799 cites W1992985562 @default.
- W2070694799 cites W1998589505 @default.
- W2070694799 cites W1998726849 @default.
- W2070694799 cites W2004480410 @default.
- W2070694799 cites W2004624052 @default.
- W2070694799 cites W2008362859 @default.
- W2070694799 cites W2013422584 @default.
- W2070694799 cites W2013913164 @default.
- W2070694799 cites W2017462729 @default.
- W2070694799 cites W2018770488 @default.
- W2070694799 cites W2019328191 @default.
- W2070694799 cites W2019447944 @default.
- W2070694799 cites W2021392220 @default.
- W2070694799 cites W2021990379 @default.
- W2070694799 cites W2023615497 @default.
- W2070694799 cites W2023773906 @default.
- W2070694799 cites W2025955392 @default.
- W2070694799 cites W2026797774 @default.
- W2070694799 cites W2027798513 @default.
- W2070694799 cites W2028288902 @default.
- W2070694799 cites W2030905502 @default.
- W2070694799 cites W2033500369 @default.
- W2070694799 cites W2034063930 @default.
- W2070694799 cites W2034433850 @default.
- W2070694799 cites W2035530492 @default.
- W2070694799 cites W2035922688 @default.
- W2070694799 cites W2040157353 @default.
- W2070694799 cites W2042296386 @default.
- W2070694799 cites W2042786942 @default.
- W2070694799 cites W2043112521 @default.
- W2070694799 cites W2044346116 @default.
- W2070694799 cites W2045044475 @default.
- W2070694799 cites W2046104095 @default.
- W2070694799 cites W2046386561 @default.
- W2070694799 cites W2048276306 @default.
- W2070694799 cites W2049611594 @default.
- W2070694799 cites W2050669150 @default.
- W2070694799 cites W2051494421 @default.
- W2070694799 cites W2053840834 @default.
- W2070694799 cites W2054426853 @default.
- W2070694799 cites W2054460330 @default.
- W2070694799 cites W2054866143 @default.
- W2070694799 cites W2057286652 @default.
- W2070694799 cites W2057429306 @default.
- W2070694799 cites W2062082319 @default.
- W2070694799 cites W2065737193 @default.
- W2070694799 cites W2066109243 @default.
- W2070694799 cites W2067415601 @default.
- W2070694799 cites W2070275357 @default.
- W2070694799 cites W2072077604 @default.
- W2070694799 cites W2072344814 @default.
- W2070694799 cites W2073185117 @default.
- W2070694799 cites W2073756380 @default.
- W2070694799 cites W2074342990 @default.
- W2070694799 cites W2074475548 @default.
- W2070694799 cites W2074811717 @default.
- W2070694799 cites W2076319970 @default.
- W2070694799 cites W2076814488 @default.
- W2070694799 cites W2077004744 @default.
- W2070694799 cites W2084088384 @default.