What is SuperDARN?
SuperDARN (Super Dual Auroral Radar Network) is an international
collaboration project by twelve countries in the world. SuperDARN
consists of 22 radars in the northern hemisphere and 11 radars inthe southern hemisphere, covering the northern and southern highand mid-latitude regions.
SuperDARN observes ionospheric plasma convection in the highand mid-latitude regions with temporal resolution of 1-2 min.
Recently, as shown in the right figure, SuperDARN is useful not only
for magnetospheric / ionospheric research but also forthermospheric and mesospheric research.
1 Jan10Feb2015
2013

SuperDARN Hokkaido
East HF radar (2006.11-)

00:06:00 UT

Exploring the boundaries of the universe and the earth
The Earth's upper atmosphere contains the thermosphere formed bysolar irradiance, and ionosphere consisting of ionized atoms andmolecules. These atmospheric layers contain a variety of phenomena. By
observing the boundary between the universe and the earth, we arecontinuously investigating the influences of ionospheric disturbance onhuman activities (car navigation, communication and so on) and theeffects of long-term solar activity on terrestrial environment.

SuperDARN Hokkaido
West HF radar (2014.10-)
Inﬂow of space plasma from Geospace

deitu
Alt 00 km
10Magneto

sphereHigh-speed ﬂow ionospheric plasma
Flow of ionospheric plasma(Plasma convection)m

0k

10Ionosphere
ThermosphereMesosphere

10km

Monitoring the occurrence ofhigh-speed plasma ﬂow
Ionospheric high-speed plasma flow (about1-2 km/s) over the Far East Russia ismonitored by the Hokkaido HF radar.
The radar is able to investigate details ofstructure and variability of distantionosphere by emitting HF radio waves
toward north-northeast and receiving
backscattered echoes.

Stratosp

herem0k

Emitting HF radio waves
for observation

Troposphere

Acoustic, gravity and tidal waves
from the lower atmosphere

Hokkaido radar as the lowest latitude
SuperDARN
Most SuperDARN radars had their fields of views in the regions
higher than 60 geomagnetic latitude until about 10 years ago.
Mid-latitude SuperDARN radars began operation in 2005, and new
discoveries are being made with these radars newly constructed bycountries such as Japan, USA and UK. The Hokkaido radar isconstructed by the Institute for Space-Earth Environmental
Research, Nagoya University, Japan, and is located at the lowest
latitude. The Hokkaido radar has great advantages for thecoordinated observations with many other scientific instruments
developed by several Japanese institutes.

Observingbackscattered echoes

International collaboration forimproved understanding ofplasma convection
Plasma convection pattern is obtained
from SuperDARN radar network. Groundnetwork experiments provide global-scale
information on near real time basis.

Speciﬁcations of the Hokkaido HF Radar
Frequency band
Maximum power
Pulse specifications
Ｄｕｔｙ ratio
Pulse length1 pulse pattern length
Time resolution
Range resolution
Antenna specification
Number of antenna

Disturbance of ionospheric plasma is captured
Wavy structure of ionospheric plasma disturbances
propagating with speed of several hundred m/s has been
captured by the radar. These structures are considered to begenerated by ionospheric instabilities.

9～16 MHz
10 kW
Multi pulses
about 2.5 %100～300 micro seconds
0.1 seconds
1 second ～ 2 mins
15 km to about 100 km
Log periodic antenna
16 (main array)
4 (Interferometer array)
Antenna heightabout 15 m
Antenna spacing15.24 m
Beam directions
0～60 degree(16 directions)
Beam width (horizontal) about 5 degree
Beam width (vertical)
about 40 degree
Maximum range
3500 km or more

SuperDARN

Hokkaido Pair of radars (HOP)

Location
Hokkaido East
(geographic coordinates)+43.53 N, +143.61 E(geomagnetic coordinates)
36.76, -144.78

Hokkaido West(geographic coordinates)+43.54 N, +143.61 E(geomagnetic coordinates)
36.77, -144.78

SuperDARN Hokkaido HF Radar
Pontomamu, Rikubetsu-town Ashoro-gun, Hokkaido 089-4346 Japan
http://cicr.isee.nagoya-u.ac.jp/hokkaido/

Ground oscillation signal transmitted up to theionosphere have been observed
Ionospheric perturbation was observed after the 2011
Tohoku Earthquake. Acoustic waves generated by seismic
waves are transmitted to the upper atmosphere andionosphere. The ionospheric disturbances travels with speedof several hundred m/s - several km/s, reflecting horizontal
propagation of ground seismic waves.

Institute for Space-Earth Environmental Research,
Nagoya University
Furo-cho, Chikusa-ku, Nagoya 464-8601 Japan
TEL: 81-52-747-6306 FAX: 81-52-747-6313
http://cicr.isee.nagoya-u.ac.jp/

Rikubetsu Observatory
Uenbetsu Rikubetsu-town Ashoro-gun, Hokkaido 089-4301 Japan
TEL & FAX: 81-156-27-8103

Oct, 2015

Institute for Space-Earth Environmental Research
Nagoya University