Van Allen Probes Observations of Second Harmonic Poloidal Standing Alfvén Waves

Long-lasting second-harmonic poloidal standing Alfvén waves (P2 waves) were observed by the twin Van Allen Probes (Radiation Belt Storm Probes, or RBSP) spacecraft in the noon sector of the plasmasphere, when the spacecraft were close to the magnetic equator and had a small azimuthal separation. Oscillations of proton fluxes at the wave frequency (∼10 mHz) were also observed in the energy (W) range 50–300 keV. Using the unique RBSP orbital configuration, we determined the phase delay of magnetic field perturbations between the spacecraft with a 2nπ ambiguity. We then used finite gyroradius effects seen in the proton flux oscillations to remove the ambiguity and found that the waves were propagating westward with an azimuthal wave number (m) of ∼−200. The phase of the proton flux oscillations relative to the radial component of the wave magnetic field progresses with W, crossing 0 (northward moving protons) or 180° (southward moving protons) at W ∼ 120 keV. This feature is explained by drift-bounce resonance (mωd ∼ ωb) of ∼120 keV protons with the waves, where ωd and ωb are the proton drift and bounce frequencies. At lower energies, the proton phase space density ( ) exhibits a bump-on-tail structure with occurring in the 1–10 keV energy range. This is unstable and can excite P2 waves through bounce resonance (ω ∼ ωb), where ω is the wave frequency

Giant Pulsations Excited by a Steep Earthward Gradient of Proton Phase Space Density: Arase Observation

AbstractWe present observational evidence of drift resonance between westward propagating odd mode standing ultralow frequency waves and energetic protons. Compressional ∼13 mHz (Pc4 band) waves and proton flux oscillations at >50 keV were detected at ∼03 hr magnetic local time by the Arase satellite on 15 April 2017. The azimuthal wave number (m number) is estimated to be ∼−50 from ground observations, while the theory of drift resonance gives m ∼− 49 for odd mode waves and ∼110‐keV protons, providing evidence that the drift resonance indeed took place in this event. We also found a steep earthward gradient of proton phase space density, which can quantitatively explain the wave excitation. The observed waves show typical features of giant pulsations (Pgs), regarding local time, m number, and flux oscillations. This study, therefore, has great implications to the field line mode structure and excitation mechanism of Pgs

地球磁気圏でのドリフトバウンス共鳴によるPc4-5地磁気脈動とイオン間のエネルギー輸送

京都大学0048新制・課程博士博士(理学)甲第22257号理博第4571号新制||理||1656(附属図書館)京都大学大学院理学研究科地球惑星科学専攻(主査)教授 田口 聡, 教授 秋友 和典, 准教授 藤 浩明学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

An Interactive Data Language software package to calculate ionospheric conductivity by using numerical models

The Inter-university Upper atmosphere Global Observation NETwork (IUGONET) project focuses on handling ground-based observational data of the upper atmosphere. To this end, the project members have been developing a data analysis software package which is based on Interactive Data Language (IDL). Filling the spatial gaps in observational data requires the use of numerical models. In this paper, we discuss an IDL software package for global ionospheric conductivity by integration of 3rd party numerical models. The model can be used to create further derived models

Effect of Running, Sodium and Potassium on Osteoporosis Due to Calcium Deficient Food Intake in Rats.

カルシウム欠乏食を2週間投与した7週齢の雌ラットは,骨の破断力が低下し,X線写真の透過度が有意に低下し,骨が折れやすい状態の骨粗鬆症になった.運動の負荷,ナトリウム付加食,カリウム付加食は,これらの低下や増加を軽減し,骨粗鬆症を阻害傾向がみられた.ナトリウム付加食やカリウム付加食では,血中のエストロゲンが増加し,尿中のデオキシピリジノリンが低下した.Seven-week old female Wistar rats fed calcium deficient food for 2 weeks succumbed to osteoporosis with significant decreases in bone fracture energy and high level of relative X-ray density. Lording of running, sodium supplying food intake and potassium supplying food intake were appeared to inhibit osteoporosis due to rise the increase of bone fracture energy and reduce the high level of relative X-ray density. Sodium supplying food intake and potassium supplying Ca^ deficienl food intake brought increase of serum estradiol level by reduction of urinary deoxypiridinoline

LCZ696 サクビトリル バルサルタン ノ キュウセイ シンキン コウソク ゴ ノ シン ホゴ コウカ

熊本大