On the energy of the poloidal magnetic field near the ionosphere

The role of the ionospheric Hall effect on the energy balance in the magnetosphere-ionosphere (MI) system coupled through the field-aligned current (FAC) is discussed. FACs lose their stored electromagnetic energy in the ionosphere through Joule dissipation; this process is caused by the closure of the FAC via the ionospheric Pedersen current carried by ions. On the other hand, the ionospheric rotational Hall current carried by electrons cannot be dissipated. However, the ionospheric rotational Hall current can also be excited by an incident FAC, causing it to radiate Poynting fluxes that lead to the growth of a poloidal-type magnetic field in the magnetosphere and atmosphere. From the viewpoint of energy conservation, a few ambiguities in the above statements may be recognized. In this paper, we clarify the energy balance of the electromagnetic disturbances between the magnetosphere, ionosphere and atmosphere. The generation of the Hall current (together with the associated poloidal magnetic field) will be shown to occur during the growth stage, when the electromagnetic energy is pumped through the divergent Hall current, regardless of how slow the growth may have been

Quantum Calculation of Classical Kinetic Equations: A Novel Approach for Numerical Analysis of 6D Boltzmann-Maxwell Equations in Collisionless Plasmas Using Quantum Computing

A novel quantum algorithm for solving the Boltzmann-Maxwell equations of the 6D collisionless plasma is proposed. The equation describes the kinetic behavior of plasma particles in electromagnetic fields and is known for the classical first-principles equations in various domains, from space to laboratory plasmas. We have constructed a quantum algorithm for a future large-scale quantum computer to accelerate its costly computation. This algorithm consists mainly of two routines: the Boltzmann solver and the Maxwell solver. Quantum algorithms undertake these dual procedures, while classical algorithms facilitate their interplay. Each solver has a similar structure consisting of three steps: Encoding, Propagation, and Integration. We conducted a preliminary implementation of the quantum algorithm and performed a parallel validation against a comparable classical approach. IBM Qiskit was used to implement all quantum circuits.Comment: 18 pages, 7 figure

Progress of the SDR-based dual-band scintillation detector development and its application for space weather study

第150回地球電磁気・地球惑星圏学会（SGEPSS）総会および講演会, 2021年10月31日-11月4

Evolution of the current system during solar wind pressure pulses based on aurora and magnetometer observations

Additional file 2: Figure S2. Same as Additional file 1 but for the July 14, 2012, event

Seasonal variation of inter-hemispheric field-aligned currents deduced from time-series analysis of the equatorial geomagnetic field data during solar cycle 23-24

The east–west component of magnetic field variation (∆D-component) at Davao station (Philippines, geomagnetic latitude: – 2.22˚N) are used to investigate the characteristics of the long-term Inter-Hemispheric Field-Aligned Currents (IHFACs) based on the time-series analysis from August 1998 to July 2020. Recent in situ satellite and ground-based observations have reported that dusk-side current polarity of IHFAC is often opposite to that of the noon IHFAC, being inconsistent with Fukushima\u27s IHFACs model. We investigated the consistency of the dusk-side IHFAC polarity derived from the observations with the polarity expected from Fukushima’s IHFACs model and examined the solar cycle dependence of IHFACs. It was confirmed that the dusk-side IHFACs during June and December solstices flow in the same direction of the noontime IHFACs, which was consistent with the IHFAC polarities suggested by the Fukushima model. The dusk-side IHFACs around March and September–November months disagreed with the Fukushima model. The ∆D variations clearly showed seasonal asymmetry in the dawn and noon sectors, whereas the ∆D variations in the dusk sector demonstrated seasonal symmetry. Solar cycle dependence of IHFACs was exhibited in the dusk sector. For the dawn and noon sectors, the yearly peak-to-peak ∆D amplitude in the later solar cycle SC24 decreased by about 35% in comparison with the earlier solar cycle SC23. In contrast, the dusk-side yearly peak-to-peak ∆D amplitude increased by about 200%. The dusk-side IHFAC yearly amplitude tended to be in inverse proportion to solar activity

Characteristics of dusk-side IHFAC polarity during storm and quiet time

第150回地球電磁気・地球惑星圏学会（SGEPSS）総会および講演会, 2021年10月31日-11月4

Seasonal dependence of semidiurnal equatorial magnetic variation during quiet and disturbed periods

The analysis of 20-year long-term semidiurnal lunar tidal variations gave the evidence that the semidiurnal variations are completely different between the magnetic quiet and disturbed periods. This is the first time that the seasonal dependence of disturbance-time semidiurnal variation has been provided from the analysis of the EE-index. We found the Kp dependence of semidiurnal variation: For full and new moon phase, counter troughs are amplified during disturbance time, possibly related to disturbance dynamo. For all moon phase, there are positive enhancements in dawn and strong depressions after sunset, resulting from the penetration of polar electric filed. For Seasonal dependence, semidiurnal variations are divided to three seasonal groups, and characterized as deep trough, enhanced crest and weak structure for D-solstice, Equinoxes and J-solstice, respectively. There is no significant longitudinal difference between Ancon and Davao, except for the amplitude of semidiurnal variations. The deep troughs occur during D-solstice and the enhanced crests during Equinoxes, at both Ancon and Davao.X Anniversary International Conference “Solar-Terrestrial Relations and Physics of Earthquake Precursors”, October 1-5, 2019, Paratunka, Kamchatka region, Russia

Development of an autonomous FM-CW ionospheric observation system based on reinforcement learning

第150回地球電磁気・地球惑星圏学会（SGEPSS）総会および講演会, 2021年10月31日-11月4

Seasonal and long-term variations in the Schumann Resonance observed at Kuju Japan

第150回地球電磁気・地球惑星圏学会（SGEPSS）総会および講演会, 2021年10月31日-11月4