Formation of the oxygen torus in the inner magnetosphere: Van Allen Probes observations

We study the formation process of an oxygen torus during the 12–15 November 2012 magnetic storm, using the magnetic field and plasma wave data obtained by Van Allen Probes. We estimate the local plasma mass density (ρL) and the local electron number density (neL) from the resonant frequencies of standing Alfvén waves and the upper hybrid resonance band. The average ion mass (M) can be calculated by M ∼ ρL/neL under the assumption of quasi-neutrality of plasma. During the storm recovery phase, both Probe A and Probe B observe the oxygen torus at L = 3.0–4.0 and L = 3.7–4.5, respectively, on the morning side. The oxygen torus has M = 4.5–8 amu and extends around the plasmapause that is identified at L∼3.2–3.9. We find that during the initial phase, M is 4–7 amu throughout the plasma trough and remains at ∼1 amu in the plasmasphere, implying that ionospheric O+ ions are supplied into the inner magnetosphere already in the initial phase of the magnetic storm. Numerical calculation under a decrease of the convection electric field reveals that some of thermal O+ ions distributed throughout the plasma trough are trapped within the expanded plasmasphere, whereas some of them drift around the plasmapause on the dawnside. This creates the oxygen torus spreading near the plasmapause, which is consistent with the Van Allen Probes observations. We conclude that the oxygen torus identified in this study favors the formation scenario of supplying O+ in the inner magnetosphere during the initial phase and subsequent drift during the recovery phase

Meridional Distribution of Middle-Energy Protons and Pressure-Driven Currents in the Nightside Inner Magnetosphere: Arase Observations

We examined the average meridional distribution of middle‐energy protons (10–180 keV) and pressure‐driven currents in the nightside (20–04 hr magnetic local time) ring current region during moderately disturbed times using the Arase satellite\u27s data. Because the Arase satellite has a large inclination orbit of 31°, it covers the magnetic latitude (MLAT) in the range of −40° to 40° and a radial distance of <6RE. We found that the plasma pressure decreased significantly with increasing MLAT. The plasma pressure on the same L* shell at 30° < MLAT < 40° was ∼10–60% of that at 0° < 4 MLAT < 10°, and the rate of decrease was larger on lower L* shells. The pressure anisotropy, derived as the perpendicular pressure divided by the parallel pressure minus 1, decreased with radial distance and showed a weak dependence on MLAT. The magnitude of the plasma beta at 30°<MLAT<40° was 1 or 2 orders smaller than that at 0°<MLAT<10°. The plasma pressure normalized by the value at 0°<MLAT<10° estimated from the magnetic strength and anisotropy was roughly consistent with the observed plasma pressure for L*=3.5–5.5. The azimuthal pressure‐gradient current derived from the plasma pressure was distributed over MLAT∼0–20°, while the curvature current was limited within MLAT∼0–10°. We suggest that the latitudinal dependence should be taken into account in interpretations of plasma parameters in successive orbits during magnetic storms

Locally Generated ULF Waves in the Martian Magnetosphere: MAVEN Observations

International audienceWe investigate Martian ultralow frequency (ULF) electromagnetic waves generated by local plasma instabilities below the Martian bow shock. Recent Mars Atmosphere and Volatile EvolutioN (MAVEN) observations have shown that ULF waves generated upstream of the Martian bow shock can propagate down to the upper ionosphere, possibly facilitating heavy ion escape from Mars by heating the ionospheric plasma. In contrast to the upstream waves oscillating near the upstream proton cyclotron frequency, we identify narrow band ULF magnetic field fluctuations with frequencies near the local proton cyclotron frequency (fcp(local)) from MAVEN data. In addition to expected proton cyclotron waves locally generated in the magnetosheath, we newly identify compressional narrow band emissions near fcp(local) (and its harmonics for some cases) in the dayside upper ionosphere and in the nightside magnetotail. The dayside waves are preferentially observed for high solar extreme ultraviolet (EUV) conditions and are often associated with ring/shell-like, hot protons of magnetosheath origin in the presence of cold, dense ionospheric protons. The nightside waves exhibit distinct preference for high-solar-EUV, strong-solar-wind conditions, under which both warm and cold protons are enhanced. The observed properties of these compressional waves are generally consistent with a proton Bernstein mode instability driven by a positive perpendicular slope in proton velocity distribution functions. The excited waves can cause perpendicular heating of thermal protons, thereby transferring energy from precipitating hot protons to cold ionospheric protons

Driftâ Bounce Resonance Between Pc5 Pulsations and Ions at Multiple Energies in the Nightside Magnetosphere: Arase and MMS Observations

A Pc5 wave is observed by the Exploration of energization and Radiation in Geospace Arase satellite in the inner magnetosphere (L ~5.4â 6.1) near postmidnight (Lâ magnetic local time ~1.8â 2.5 hr) during the storm recovery phase on 27 March 2017. Its azimuthal wave number (mâ number) is estimated using two independent methods with satellites and ground observations to be â 8 to â 15. The direct measurement of the mâ number enables us to calculate the resonance energy. The flux oscillations of H+ and O+ ions at ⠥ 56.3 keV are caused by drift resonance and those of O+ ions at ⠤ 18.6 keV by bounce resonance. Resonances of O+ ions at multiple energies are simultaneously observed for the first time. The enhancement of the O+/H+ flux ratio at ⠤ 18.6 keV indicates selective acceleration of O+ ions through bounce resonance.Plain Language SummaryGeomagnetic pulsations are magnetic fluctuations excited by solar wind or plasma instabilities in the magnetosphere. Pc5 waves are continuous geomagnetic pulsations with a period of 150â 600 s. A Pc5 wave was observed in the inner magnetosphere during a magnetic storm on 27 March 2017. It propagated westward with a wave number of 8 to 15 and resonated with charged particles, resulting in oscillations of the H+ and O+ ion fluxes at ⠥ 56.3 keV and the O+ ion fluxes at ⠤ 18.6 keV. Resonances of O+ ions at multiple energies are simultaneously observed for the first time. At the same time, the O+/H+ flux ratio at ⠤ 18.6 keV enhanced corresponding to the O+ ion flux oscillations, which indicates selective acceleration of O+ ions through resonances.Key PointsA largeâ amplitude Pc5 wave is observed by Arase and MMS1 in the postmidnight region at L > 5.4 during the storm recovery phaseWe estimate the mâ number of the Pc5 wave to be â 8 to â 15 by using two independent methods with satellites and ground observationsWe simultaneously observe the drift resonance for H+ and O+ ions at ⠥ 56.3 keV and bounce resonance for O+ ions at ⠤ 18.6 keVPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145558/1/grl57758_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145558/2/grl57758.pd

Meridional Distribution of Middle-Energy Protons and Pressure-Driven Currents in the Nightside Inner Magnetosphere: Arase Observations

We examined the average meridional distribution of middle‐energy protons (10–180 keV) and pressure‐driven currents in the nightside (20–04 hr magnetic local time) ring current region during moderately disturbed times using the Arase satellite's data. Because the Arase satellite has a large inclination orbit of 31°, it covers the magnetic latitude (MLAT) in the range of −40° to 40° and a radial distance of <6RE. We found that the plasma pressure decreased significantly with increasing MLAT. The plasma pressure on the same L* shell at 30° < MLAT < 40° was ∼10–60% of that at 0° < 4 MLAT < 10°, and the rate of decrease was larger on lower L* shells. The pressure anisotropy, derived as the perpendicular pressure divided by the parallel pressure minus 1, decreased with radial distance and showed a weak dependence on MLAT. The magnitude of the plasma beta at 30°<MLAT<40° was 1 or 2 orders smaller than that at 0°<MLAT<10°. The plasma pressure normalized by the value at 0°<MLAT<10° estimated from the magnetic strength and anisotropy was roughly consistent with the observed plasma pressure for L*=3.5–5.5. The azimuthal pressure‐gradient current derived from the plasma pressure was distributed over MLAT∼0–20°, while the curvature current was limited within MLAT∼0–10°. We suggest that the latitudinal dependence should be taken into account in interpretations of plasma parameters in successive orbits during magnetic storms

Evaluation of Glucose Tolerance, Post-Prandial Hyperglycemia and Hyperinsulinemia Influencing the Incidence of Coronary Heart Disease

Background: Recently, the frequency of patients who have glucose intolerance has been increasing in Japan. Glucose intolerance and insulin resistance/hyperinsulinemia are thought to influence the progression of atherosclerosis. The present study examined glucose tolerance, insulin resistance, post-prandial hyperglycemia/hyperinsulinemia and coronary risk factors by using 75 g oral glucose tolerance test (OGTT). Patients and Methods: Coronary risk factors were examined and OGTT with measurement of plasma glucose and serum insulin was done to evaluate the glucose metabolism and insulin resistance in 263 patients who underwent coronary angiography; 202 subjects were diagnosed as having coronary heart disease (CHD) and 61 subjects were normal. We compared the two groups. Results: The rate of having diabetes was significantly high in the CHD group. From the result of OGTT, 22.3% of CHD patients had diabetes mellitus and 36.6% had impaired glucose tolerance, thus the total glucose intolerance rate was 57.7% in the CHD group. No significant difference was noted in the homeostatic model assessment-R (HOMA-R), but glucose and insulin at 2 hours after OGTT were all significantly high in the CHD group. Conclusion: The rate of glucose intolerance and the levels of post-prandial glucose and insulin were high in the CHD group. We concluded that the post-prandial hyperglycemia and hyperinsulinemia influenced the incidence of CHD

As origens do judô brasileiro: a árvore genealógica dos medalhistas olímpicos Las orígenes del judo brasileño: el árbol genealogica de los ganadores de medallas olímpicas The roots of Brazilian judo, the genealogic tree from olympic medalists

O Brasil participou de todas as edições dos Jogos Olímpicos (JO) no judô, nos quais 12 atletas brasileiros conquistaram medalhas. O objetivo deste estudo foi elaborar uma "árvore genealógica judoística" do judô brasileiro a partir destes medalhistas. A metodologia utilizada foi História Oral de Vida Híbrida. Foram entrevistados os 12 medalhistas brasileiros em JO e seus professores. Identificamos todos os formadores dos professores destes medalhistas, até encontrar os "genearcas", aqueles que chegaram ao Brasil com condições de transmitir estes conhecimentos. As informações obtidas com os entrevistados foram analisadas juntamente com outros documentos. Maeda e Satake foram os primeiros japoneses a chegar e fazer demonstrações de judô no Brasil, a partir de 1914. Ryuzo Ogawa, que fundou a Budokan em 1936, foi o genearca que influenciou o maior número destes atletas. O primeiro medalhista brasileiro, Chiaki Ishii, foi também um genearca, pois influenciou outros atletas e professores.<br>Brasil ha participado en todas las ediciones de los Juegos Olímpicos (JO) en judo, aunque 12 atletas brasileños ganaron medallas. El objetivo de este estudio fue preparar un árbol genealogica judoística de estos mismos medallistas olimpicos de judo. La historia oral de vida híbrida es la metodología utilizada. Entrevistamos a los 12 medallistas brasileños y sus entrenadores. Se identificaron todos los entrenadores formadores de estos medallistas también, hasta que encuentre los genearcas, que llegaran a Brasil y lograron hacer la transmisión de este conocimiento. La información obtenida de los encuestados fueron analizadas junto con otros documentos. Maeda y Satake fueron los primeros a llegar y dar demostraciones de judo en Brasil, desde 1914. Ryuzo Ogawa, quien fundó Budokan en 1936, fue el genearca que influyó el mayor número de estos atletas. El primer medallista brasileño, Chiaki Ishii, fue también un genearca al influir otros atletas y entrenadores.<br>Brazil has participated in all editions of the Olympic Games (OG) in Judo, and 12 Brazilian athletes were medalists. The goal of the present study is to prepare a Judo genealogical tree from the Brazilian Judo of those medalists. The methodology used was the oral history of life hybrid. The 12 Brazilian Judo medalists and their coaches were interviewed. After identified all of the former coaches from those medalists, we were able to find the genearches, those who came into Brazil with the possibility to transmit these knowledge. The answers obtained from the respondents were analyzed together with other documents. Maeda and Satake were the first ones to arrive in Brazil and began the demonstrations, in 1914. Ryuzo Ogawa, who found Budokan in 1936, was the genearch who influenced the highest number of those athletes. The first Brazilian medalist, Chiaki Ishii, was a genearch as well, since he influenced other athletes and coaches