Search Publications
How to improve our understanding of solar wind-magnetosphere interactions on the basis of the statistical evaluation of the energy budget in the magnetosheath?
Sorriso-Valvo, Luca; Plaschke, Ferdinand; Nakamura, Rumi +6 more
Solar wind (SW) quantities, referred to as coupling parameters (CPs), are often used in statistical studies devoted to the analysis of SW–magnetosphere–ionosphere couplings. Here, the CPs and their limitations in describing the magnetospheric response are reviewed. We argue that a better understanding of SW magnetospheric interactions could be ach…
Solar Activities Associated with 3He-rich Solar Energetic Particle Events Observed by Solar Orbiter
Nitta, Nariaki V.; Ho, George C.; Mason, Glenn M. +5 more
A series of 3He-rich solar energetic particle (SEP) events was observed by Solar Orbiter in May 2021 at a radial distance of 0.95 AU. An isolated active region AR 12824 was likely the ultimate source of these SEP events. The period of the enhanced flux of 3He was also a period of frequent type III bursts in the decametric-hectometric range, confir…
The basic solar wind speed distribution and its sunspot cycle variations
Akasofu, Syun-Ichi; Lee, Lou-Chuang
In this paper, it is suggested that the latitudinal solar wind speed observed by the Ulysses spacecraft during the lowest solar activity (when both the ecliptic and magnetic equators coincide) may be identified as the basic speed distribution throughout the solar cycle. We demonstrate this suggestion by rotating this particular Ulysses distributio…
A Review of Instrument Techniques to Measure Magnetospheric Cold Electrons and Ions
Reisenfeld, Daniel B.; Maldonado, Carlos A.; Resendiz Lira, Pedro A. +3 more
A review of the instruments and techniques to directly measure the full distributions of the cold-ion and cold-electron populations in the magnetosphere is presented. Relatively few studies have focused on the cold plasma populations of the magnetosphere due to difficulties associated with obtaining measurements. The cold particle populations are …
The High Energy X-ray Probe (HEX-P): supernova remnants, pulsar wind nebulae, and nuclear astrophysics
Woo, Jooyun; An, Hongjun; Mori, Kaya +29 more
HEX-P is a probe-class mission concept that will combine high spatial resolution X-ray imaging (<10″ full width at half maximum) and broad spectral coverage (0.2–80 keV) with an effective area far superior to current facilities (including XMM-Newton and NuSTAR) to enable revolutionary new insights into a variety of important astrophysical probl…
Using machine learning to characterize solar wind driving of convection in the terrestrial magnetotail lobes
Glassmeier, Karl-Heinz; Halekas, Jasper S.; Haaland, Stein +2 more
In order to quantitatively investigate the mechanism of how magnetospheric convection is driven in the region of magnetotail lobes on a global scale, we analyzed data from the ARTEMIS spacecraft in the deep tail and data from the Cluster spacecraft in the near and mid-tail regions. Our previous work revealed that, in the lobes near the Moon's orbi…
A possible mechanism for the formation of an eastward moving auroral spiral
Grigorenko, Elena E.; Kronberg, Elena A.; Partamies, Noora +1 more
The generation process of auroral spirals is described by different theories varying for their morphology and surrounding conditions. Here, a possible mechanism is proposed for an eastward moving auroral spiral, which was observed in Tromsø, Norway, during the expansion phase of a substorm on 18 September 2013. Measurements from the THEMIS-A and C…
The universality of power law slopes in the solar photosphere and transition region observed with HMI and IRIS
Aschwanden, Markus J.; Nhalil, Nived Vilangot
We compare the size distributions of self-organized criticality (SOC) systems in the solar photosphere and the transition region, using magnetogram data from Helioseismic and Magnetic Imager (HMI) and Interface Region Imaging Spectrograph (IRIS) data. For each dataset we fit a combination of a Gaussian and a power law size distribution function, w…
The nearby astrometric-spectroscopic binary star Hip 68682
Wang, Xiaoli; Fu, Yanning; Chen, Yue +1 more
The nearby astrometric-spectroscopic binary star Hip 68682 has an orbital period of ∼ 9.88 yr. The dynamical state (component masses and kinematic parameters) of this system is redetermined by fitting all the observational data available to us, including the radial velocity data (RVD), the relative position data (RPD), and the Hipparcos Intermedia…
Ion kinetic effects linked to magnetic field discontinuities in the slow Alfvénic wind observed by Solar Orbiter in the inner heliosphere
D'Amicis, Raffaella; Perrone, Denise; Perri, Silvia +2 more
Slow solar wind, sharing magnetic and plasma properties typical of fast wind, the so-called slow Alfvénic wind, has been widely observed in the heliosphere. Here, we report an analysis of the turbulent properties of a slow Alfvénic stream observed by Solar Orbiter at 0.64 AU. This solar wind stream is characterized by well distinguishable regions,…