PPARC seminar news #3 in FY2018


2018/4/23 (Mon.) 9:00-12:00 @ Science Complex C N407

Chairperson: Koga

Yasumasa Kasaba 笠羽康正(Professor)
3 news are introduced, related to 3 topics.
(1) Arase: Evaluation of the Wire Probe Antenna (WPT) and Electric Field Detector (EFD) of Plasma Wave Experiment (PWE) aboard ARASE: The data qualifications and cautions from the first-year observations
(2) JUICE: The Radio & Plasma Wave Investigation (RPWI) for JUICE for the investigation of Jupiter and Icy Moons System: Contributions from Japan
(3) Exploring the Atmosphere of MArs and VEnus with Remote Observations and Simulations: A Belgium-Japan partnership (AMAVERO) 2017-2018

(1) This paper shows the evaluation results of Wire Probe Antenna (WPT) and Electric Field Detector (EFD), which are one of the key parts of Plasma Wave Experiment (PWE) aboard the Arase (ERG) Satellite. The data qualifications and cautions from the first-year observations are shown for the scientists who expect to utilize this data sets. It is well known that the potential and electric field measureed by WPT and EFD has the tricky characteristics, which is common in the similar instruments aboard the MMS, Themis, and many previous spacecraft. In this paper, we summarize the status of their calibrations. Including the subtraction of spacecraft Velocity x B field, we introduce the potential problems for the data analyses of electric field in low frequency range caused by the effects of surrounding electron plasma characteristics on the spacecraft potential, wake effect caused by the spacecraft motions, and possible artificial contaminations, in order to support the fruitful scientific results from this valuable data sets with careful treatments.
(2) In 2018 we develop the QM/PFM/FM of Radio & Plasma Wave Investigation (RPWI) aboard ESA JUICE. RPWI provides an elaborate suite for electromagnetic fields and plasma environment around Jupiter and icy moons, with 4 Langmuir probes (LP-PWI; 3-axis E-field -1.6 MHz, and cold plasmas), a search coil magnetometer (SCM; 3-axis B-field -20 kHz), and a tri-dipole antenna system (RWI; 3-axis E-field 0.08-45 MHz, 2.5-m tip-to-tip length). RWI with High Frequency Receiver (HF) provide the highest sensitivity reaching the galactic background for the highly-resolved Jovian radio emissions from magnetosphere (aurora etc.), atmosphere (lightning), and icy moons. Its direction and polarization capabilities enable us to identify the source locations and characteristics. Their developments are under the collaboration of Japan, France, Poland and Sweden, based on the H/W and S/W designs of Kaguya-LRS / BepiColombo-PWI / Arase-PWE and Cassini-RPWS. In this paper, we introduce key actions taken in recent years to achieve the best performances and quiet environment with enough tolerance for wide temperature range around Venus-Jupiter and harsh plasma environment (charging & intense radiation). As a byproduct, we try the passive subsurface radar (PSSR) to sound the icy crusts of Galilean satellites, by the reflections of Jovian HOM/DAM. For continuous and coherent waves, reflector information is determined by spectrum patterns caused by the interference among the direct wave, reflected one from surface, and scattered one by subsurface. For burst waves, the reflection component is determined by cross-correlation of the waveforms for ~msecs length. Although it is not easy to reach the top of subsurface ocean by strong attenuation of the ice close to its melting temperature (>50 dB/km), we are looking forward to see real data and support the subsurface studies executed by RIME (active radar sounder) and many payload teams who have much interest to this topic.
(3) In 2017-2018 FY, Japan-Belgium collaboration program AMAVERO (Exploring the Atmosphere of MArs and VEnus with Remote Observations: A Belgium-Japan partnership) is running. This project studies those aspects by collecting observational datasets from Belgium and Japan. Belgian side provides the data taken by European Mars Express (MEx), ExoMars Trace Gas Orbiter (TGO), and Venus Orbiter Venus Express (VEx). From Japan, the data taken by ground-based and space-borne telescopes with Japanese Venus Orbiter Akatsuki are provided. Moreover, we share te numerical tools to analyze the observational datasets, and develop the numerical models of the atmospheres to interpret the observational results.

Asuka Hirai 平井あすか(M2)
Title: Temporal and spatial correspondence of Pc1/EMIC waves and energetic electron precipitation with ground-based observation on 27 March, 2017
Abstract: Electromagnetic ion cyclotron (EMIC) waves in the Pc1-Pc2 frequency range are thought to cause the loss of relativistic electrons in the outer radiation belt into the atmosphere due to pitch angle scattering. On the other hand, it is not easy to observe temporal and spatial proximities of both phenomena.
In this study, we show a temporal and spatial correspondence of Pc1/EMIC waves and energetic electron precipitation during the main phase of a geomagnetic storm on 27 March, 2017.
Pc1 was observed by induction magnetometers in North America (PWING and CARISMA stations) and simultaneously, energetic electron precipitation with typically energies higher than 100keV was detected by VLF/LF radio waves. Isolated proton auroras which was useful to identify ionospheric sources of EMIC waves were observed by the all sky imager at Athabasca (one of the PWING stations).
When proton auroras appeared on the VLF/LF radio propagation paths on which energetic electron precipitation was detected, we found a good correspondence between the time variation of energetic electron precipitation and Pc1 wave power. The result and the calculation of difference of propagation time between energetic electron and EMIC wave from magnetic equator to the ionosphere indicate that EMIC waves scattered energetic electrons through the wave-particle interaction near the equatorial plane and that electrons precipitated into the atmosphere corresponding to the time variation of Pc1 wave power.

*** PPARC seminar schedule (v1.1 /20180409) ***
Date, start time, presenters, (chairperson)
18/04/09(Mon) 9:00- Obara, Sakanoi (Kagitani)
18/04/16(Mon) 9:00- Fukizawa (Misawa)
18/04/23(Mon) 9:00- Kasaba, Hirai (Koga)
18/05/07(Mon) 9:00- Yagi, Watanabe (Obara)
18/05/14(Mon) 9:00- Misawa, Suzuki (Kasaba)
18/05/20-5/24 JpGU
18/05/28(Mon) 9:00- presentations of B4-experiments (4) (Tsuchiya)
6/3-8 AOGS
18/06/11(Mon) 9:00- Yamaguchi, Fujimoto (Sakanoi)
18/06/18(Mon) 9:00- Ooura, Kanbara (Kagitani)
18/06/25(Mon) 9:00- Ishikawa, Tsuchiya (Misawa)
18/07/02(Mon) 9:00- Koga, Kagitani
18/07/09-13 MOP conference
18/07/14-23 COSPAR2018
18/07/16(Mon) Holiday
18/07/23(Mon) 9:00- an optional day

D/1回: Koga
M2/1回: Hirai, Watanabe, Fukizawa, Ishikawa
M1/1回: Yagi, Suzuki
B4/2回: Yamaguchi, Fujimoto, Ooura, Kanbara


*** C-group seminar 2018 schedule (ver1.3 on 2018-03-25) ***
March 30 (Fri) D-2 intermediate report (Aizawa)
April 26 (Thu) Lecture(Kimura)
May 10 (Thu) JpGU Rehearsal
#May 20-24 JpGU
May 31 (Thu) Poster#1 & D-report (STPPx1, PAT: Dai, Akiba, PPARC:*Koga, Hirai)
#June 3-8 AOGS
June 14 (Thu) Poster#2 & D-report (STPPx1, PAT: Hubig, Toriumi, PPARC: Fukisawa, Watanabe)
June 28 (Thu) Poster#3 & D-report (STPPx1, PAT: Toyooka, Yoshida, PPARC: Ishikawa, Yagi)
July 5 (Thu) Poster#4 & D-report (STPPx1, PAT: *Takami, Nakamura, Yagi, PPARC: Suzuki)
#July 9-13 MOP, 14-22 COSPAR
* indicates speaker for short report (D1 & D2)
STPP:D3x1,D1x1,M2x1,M1x1 (4)
PAT:D3x1, D2x1, M2x3, M1x4 +1(Hubig) (9)
PPARC: D2x1, M2x4, M1x2, (7)
total: 20 (/4=5)