MMS observations of explosive filamentary current within two adjacent ion scale flux ropes

2021 ◽  
Author(s):  
Yuchen Xiao ◽  
Shutao Yao ◽  
Ruilong Guo ◽  
Quanqi Shi ◽  
Anmin Tian ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Energy Dissipation ◽  
Magnetic Reconnection ◽  
Temporal Resolution ◽  
Pitch Angle ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
The Past ◽  
Flux Ropes ◽  
Spatio Temporal

<p>Flux ropes have attracted extensive attention due to their importance in studying instantaneous magnetic reconnection over the past years. Recently, with the improvement of high spatio-temporal resolution measurements, kinetic-scale flux ropes have been detected. However, their generation and energy energization are still unclear. In this study, electron-scale filamentary currents within two adjacent ion scale flux ropes are observed using MMS data. We find that:</p><p>1. Intense and explosive filamentary currents in parallel and perpendicular directions are found inside the flux ropes.</p><p>2. The electron pitch angle distribution appears "X" like shape, and could be caused by the electron acceleration.</p><p>3. The filamentary current appears in the center of the "X" distribution.</p><p>The filamentary currents are important and are considered to be the evidence of secondary reconnection [Wang et al., 2020]. The observations in our study are important to reveal the particle acceleration and energy dissipation in magnetic reconnection.</p>

scholarly journals Comparison between CNA and energetic electron precipitation: simultaneous observation by Poker Flat Imaging Riometer and NOAA satellite

2005 ◽  
Vol 23 (5) ◽  
pp. 1555-1563 ◽  
Author(s):  
Y.-M. Tanaka ◽  
M. Ishii ◽  
Y. Murayama ◽  
M. Kubota ◽  
H. Mori ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Electron Flux ◽  
Energetic Electron ◽  
Energetic Particles ◽  
Electron Precipitation ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Loss Cone ◽  
Isotropic Pitch ◽  
Trapped Electron

Abstract. The cosmic noise absorption (CNA) is compared with the precipitating electron flux for 19 events observed in the morning sector, using the high-resolution data obtained during the conjugate observations with the imaging riometer at Poker Flat Research Range (PFRR; 65.11° N, 147.42° W), Alaska, and the low-altitude satellite, NOAA 12. We estimate the CNA, using the precipitating electron flux measured by NOAA 12, based on a theoretical model assuming an isotropic pitch angle distribution, and quantitatively compare them with the observed CNA. Focusing on the eight events with a range of variation larger than 0.4dB, three events show high correlation between the observed and estimated CNA (correlation coefficient (r0)>0.7) and five events show low correlation (r0<0.5). The estimated CNA is often smaller than the observed CNA (72% of all data for 19 events), which appears to be the main reason for the low-correlation events. We examine the assumption of isotropic pitch angle distribution by using the trapped electron flux measured at 80° zenith angle. It is shown that the CNA estimated from the trapped electron flux, assuming an isotropic pitch angle distribution, is highly correlated with the observed CNA and is often overestimated (87% of all data). The underestimate (overestimate) of CNA derived from the precipitating (trapped) electron flux can be interpreted in terms of the anisotropic pitch angle distribution similar to the loss cone distribution. These results indicate that the CNA observed with the riometer may be quantitatively explained with a model based on energetic electron precipitation, provided that the pitch angle distribution and the loss cone angle of the electrons are taken into account. Keywords. Energetic particles, precipitating – Energetic particles, trapped – Ionosphere-magnetosphere interactions

The Pitch Angles of Electrons in Jupiter’s Radiation Belt

1976 ◽  
Vol 3 (1) ◽  
pp. 53-55 ◽  
Author(s):  
J. A. Roberts
Keyword(s):  
Radio Emission ◽  
Pitch Angle ◽  
Radiation Belt ◽  
Synchrotron Emission ◽  
Angle Distribution ◽  
Space Probe ◽  
Frequency Range ◽  
Pitch Angle Distribution ◽  
5 Ghz ◽  
Apparent Conflict

The radio emission from Jupiter in the frequency range from ∽ 50 MHz to ∽ 5 GHz is mainly synchrotron emission from electrons in the intense radiation belt which surrounds Jupiter out to several planetary radii. Information about the pitch angles of these electrons can be derived both from the radio observations and from the Pioneer space probe observations. In this communication we discuss the pitch angle distribution inferred from the radio data and the apparent conflict with the Pioneer data.

scholarly journals Solar cosmic rays by the ground level observation: anisotropy

2019 ◽  
Vol 127 ◽  
pp. 02027
Author(s):  
Yury Balabin ◽  
Aleksei Germanenko ◽  
Boris Gvozdevsky
Keyword(s):  
Inverse Problem ◽  
Cosmic Rays ◽  
Pitch Angle ◽  
Ground Level ◽  
Problem Solution ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Solar Cosmic Rays ◽  
Inverse Problem Solution ◽  
Distribution Form

Nine large GLE events have been studied by the improved methodic of the inverse problem solution. The problems of the SCR anisotropy form setting have been in detail worked out in the new methodic. The SCR pitch-angle distribution form is automatically selected in solution search. It significantly improves the solutions convergence.

Pitch angle distribution of He observed at “MIDORI” satellite

1999 ◽  
Vol 23 (3) ◽  
pp. 547-550
Author(s):  
C Kato ◽  
K Munakata ◽  
T Kohno ◽  
H Miyasaka ◽  
I Yamagiwa ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Angle Distribution ◽  
Pitch Angle Distribution
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