== 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