== new title == radar study of ionospheric irregularity
TRANSCRIPT
== New title ==Radar study of ionospheric irregularity
(EAR results brief review)+
Equatorial MU (EMU) radar project+
SMILES-2: A satellite to measure temp/wind of whole atmosphere
(30-160km, day & night) … from poster by NICT Ochiai-san
Mamoru Yamamoto
(RISH, Kyoto University)
MU radar (Shigaraki, Japan)(Completed in 1984, Multi-purpose MST/IS radar)
Frequency: 46.5MHz, Output power: 1MWAntenna: 103m Φ (475 crossed Yagis)
IEEE awarded milestone to Kyoto Univ. and Mitsubishi
Electric Co. for MU radar as first MST radar with 2D active-
phased array antenna system. (Award in May 2015)
Equatorial Atmosphere Radar (EAR)(Installed in 2001, long-time experiment)
EAR
Antenna View:560 Yagi-antenna arrays (110m diameter)Peak Power: 100 kW
Kototabang, West Sumatra, INDONESIA(0.20S, 100.32E)
TR module
Yagi antenna
TR: transmitter and receiver
Study of Equatorial Speread-F (ESF) with EAR
EAR can observe Intense echoes from the Equatorial Spread-F (ESF) (= plasma bubble).
They are coherent echoes from ionospheric irregularites of half-wavelength scale (~3 m).
Observation direction is limited perpendicular to the geomagnetic field (B).
B
EAR
EAR Multiple Beam Observation of ESF echoes
Growing FAI
Terminator
SOUTH
EAST
WEST
Eastward propagation of FAI echoing region is clearly seen.
Growing FAIs were detected in the observation region with 11 beam directions.
Motion of ESF echoes (post-sunset)East West
Onset timing of ESF echoes over EAR
(Yokoyama et al., GRL, 2004)
Longitudinal distribution of plasma bubbles
Case study on March 24, 2004
Average: 690 km (S.D.: 180 km)
Minimum: 370 km
Maximum: 1000 km
Possible modulation of plasma bubbles owing to gravity waves.
Distance: ~ 500 km in average
Spatial interval between PBs A-D
Four regions of plasma bubbles (A、B、C、D) were observed during 20-0 LT
Typical interval between PB clusters (16 cases)
Possible seeding of ESF from LSWS
EAR finding• 400~500 km
periodic zonal distribution of ESF (EPB) active region was found from EAR experiment.
LSWS seeding of ESF• ~400 km zonal
modulation of bottom ionosphere (= large-scale wave structure; LSWS) can be a seed of ESF (EPB).Original figure from R. Tsunoda
Comparison of MU Radar, EAR, and PANSYMU radar EAR PANSY
Photo
Lon, Lat 34.85N, 136.11E 0.20S, 100.32E 69.00S, 39.59ENumber of antenna 475 560 1045
Number of RX channel 25 ch 1 ch 55 ch
Antennaaperture
8,300 m2
(103 m diameter)9,500 m2
(110 m diameter)20,000 m2
(160 m diameter)
TX module output
2.2 kW 200 W 500 W
Peak output power
1 MW 100 kW 500 kW
Antenna aperture×Output power(Relative numberproportional to the radar sensitivity)
1.0 (standard) 0.11 1.2
1-group = 19 YagisArray consists of 55 groups(19 Yagis x 55 = 1045)
Designed antenna array
�EMU SystemFrequency: 47MHzAntenna: Active-phased array
(163m diameter, Total 1045 Yagis)Output power: 500kW PEP)
Subsystems:TR module at each Yagi-antennaMulti-channel receiversRadar controller / Data processor
Equatorial MU (EMU) Radar
– Troposphere and lower stratosphere• Good data up to ~20km height.
– Mesosphere experiment• 60-80km height, daytime echoes
• Atmospheric tides and gravity waves
– IS (incoherent scatter) experiment• Ionosphere plasma density, drift, and temperature
measurement.
– Radar interferometry with multi-channel receivers• Radar imaging observations.
• Meteor-echo observations.
High sensitivity
Multi channel RX
New observations with EMU
� PI: T. Tsuda @ RISH
� Institutes: RISH, NIPR, ISEE, Kyushu Univ.
1. Equator: Develop Equatorial MU Radar (EMU) at the EAR site
2. Polar region: Develop EISCAT_3D radar in Europe
3. Global: Deploy global network of airglow imager and magnetometer.
SUN
Particls
Max at
polar
region
Aurora
heating北極南極 赤道
Atmosphere
Ionosphere
(PANSY) EMU EISCAT_3D
New giant radars
Science Council of Japan: Masterplan 2014
MEXT: Roadmap 2014 ProjectEnergy from Sun
Radiation
Particls
Atmos. heating
Magnetosphere
Geomag
Radiation
Max at
equator
Study of Coupling Processes in the Solar-Terrestrial System
� SMILES-2 is a new satellite � Working group at JAXA/ISAS prepares
for a satellite in orbit in 2022 or later. (PI: M. Shiotani @ RISH)
� Follows success of SMILES from ISS (Superconducting Submillimeter-wave Limb-Emission Sounder).
� SMILES-2 impacts us much.� Temperature and wind from resonance
of atomic Oxygen (2THz) etc with quite wide coverage of 30-160km height + day and night in time.
World 1st sub-mm radiometer at 4K
Concentrate on atmospheric chemistry
Radiometer at 4K for sub-mm + THz band
Add wind/temp measurement capability.
Summary
• Radar study of ionospheric irregularity
– Successful for QP echo & MSTID with MU radar, and ionospheric bubble with EAR. Multi-instrument with rocket, satellite, airglow imager, GPS network etc was important.
• Equatorial MU (EMU) radar
– New big MST + IS radar Indonesia. Proposed to Japan government. Now the project list, wait for the fund. EISCAT_3D (Japan part) is included in the package.
• SMILES-2
– New satellite under development after SMILES success from ISS. Winds and Temperature will be measured by sub-millimeter + THz radiometer in 30-160km height range.
Support from scientific
community is very important!!
15th MST Radar workshop (MST15/iMST2)18th EISCAT Symposium
in Tokyo on 26-31 May 2017
JpGU-AGU joint meeting (May 20-25)@ Makuhari (East Tokyo)
EISCAT Sympo http://eiscat.nipr.ac.jp/about/18th_eiscat_symposium.htmlMST WS http://www.rish.kyoto-u.ac.jp/mst15/
National Institute of Polar Research (NIPR)Tachikawa, Tokyo, Japan
EISCAT symposium (May 26-30)MST Radar Workshop (May 27-31)
@ NIPR, Tachikawa (West Tokyo)
May 2017, please visit Japan again!!
Eastward drift of plasma bubbles
Distribution of eastward drift of PBs
Eastward drift speed of plasma bubbles can be estimated from multi-beam experiment with the EAR.
Eastward drift speed decreases with time after the sunset.
Speed is determined from inclination
東
西
At the sunset: 140 m s-1
Speed decreases 10 m s-1/hr
Correlation coef.: -0.77
Average over three years (37 cases)Regression
curve