New Perspective of Ionosphere Research - Lithosphere Atmosphere Ionosphere coupling –

K.-I..Oyama1, and J.Y.Liu1 ( Y.Kakinami 1, T.Kodama2, and H.Kamogawa3 )

　 　 1.Institute of Space Science,National Central University, Taiwan

2.Japan Aero Space Exploration Agency,Tukuba,Japan

3. Tokyo Gakuge Univ.,Tokyo,Japan

16:20-16:40 Nov.3 2008 Cheng Kung University,Taiwan

Great Hanshin-Awaji Earthquake M.7.3 Jan 17,1995 Death 6437 Unknown 3,Injured 43792, 10 chouen (80 chouenn)

Oyama et al, J.Geophys.Res.,2008

　 　 　 　 　 　 　 　　　　　　　　　　 CONTENT

1. Past history of the study on the effects of earthquake by means of satellite data

2. Results from Japanese Hinotori satellite

3. Role of electric field and its possible generation mechanism………………………………………………

3. Satellite proposal 　

Mini satellites and Small satellite,international collaboration

4. Need of international collaboration

This paper stresses that new academic field is being opened regarding the effects of EQ on ionosphere

The space projects where the ionospheric observation and the

earthquake precursors were studied

• Alouette - 1964 • Cosmos-274 -1969 • OGO-6 - 1969 • OVI-17 - 1969 • ISIS-2 – 1971• АЕ-С -1973 • GEOS-1 and 2 - 1978 • Intercosmos-19 – 1979

Aureol-3 –1981

• Intercosmos-Bulgaria 1300 – 1982• Salyut-7 - 1985• Meteor-3 - 1986• Cosmos 1809 -1987• ISIS-2 – 1971• Activny -(Intercosmos-24) -1989• TOPEX/Poseidon - 1996• GEOS-1 and 2 - 1978 • MIR Space Station• DE-2 • Quakesat• DEMETER• HINOTORI

Abnormal behavior of Ne, TEC, VLF, ion composition, particle precipitation, and atmospheric glow have been reported ,which might have been associated with earthquake.

Cloud ,Temperature rise :recent remote sensing satellites

Ionosphere

Neutral atmosphere is partly ionized by solar EUV in the mid/low latitude regions . The ionosphere thus formed is modified

by wind and electric field under the

geomagnetic field.

Mixture of electrons, ions of various species such as NO+ and O+,and neutral particles

Temperatures are defined for these three particles such as Te,Ti and Tn

1/2m 〈 v2 〉 = 3/2kT

Te is most sensitive

Chemical Reaction

Dynamics

How to find the earthquake effects on ionosphere (for ex. ….. Te) ?

1 The instrument should be good enough to give reliable values

2. Should understand as many features as possible of the ionosphere , such as morning overshoot, equator anomaly , plasma bubble, season ,solar flux, longitude , latitude, local time time variation 3. construct a model for quiet condition ( longitude,latitude ,local time,season,solar flux at single height)

4. study the deviation of Te from the model

This is the history how I was convinced the existence of the effects of earthquake on ionosphere

( P.S.S., Ann.Geophys, J.G.R.)

•(EQ1) 1981/11/22 15:05 N18.75 E120.84 24km Ms6.7

•(EQ2) 1982/1/11 6:10 N13.75 E124.36 45km Ms7.4

•(EQ3) 1982/1/24 6:08 N14.09 E124.35 37km Ms6.6

Study of the effect of the Earthquake M≥6.5 (USGS)

２．Ｒｅｓｕｌｔｓ　ｆｒｏｍ　ＨＩＮＯＴＯＲＩ　 satellite

• Inclination;31 degrees• Height;576-644 km• Electron Density & Temperature• 1981/2/1-1982/6/30/

Launched from KSC in 1981 February

Impedance Probe (Ne) Oya,H.,T.Takahashi,and S.Watanabe,, J.Geomag.Geoelectr.,38,111-

124,1986.

Electron Temperature Probe(Te) Hirao, K. and K.- I.Oyama, J.Geomag Geoelectr . ,22,239-402,1970.

Su, Y. Z., K.-I. Oyama, G. J. Bailey, T. Takahashi and S. Watanabe, J. Geophys. Res., 100, 14591, 1995.

.Oyama, K.-I., M. A. Abdu, N. Balan, G. J. Bailey, S. Watanabe, T. Takahashi, E. R. de Paula, I. S. Batista, H. Oya and F. Isoda, J. Geophys.Res.,102,417, 1997.

Solar flux variation of Te

Northern winter

Examples of the deviation of Te and Ne from the model for EQ1 in

the afternoon overshoot for EQ1. 2 days before EQ1 (a)(satellite pass, 4065), and 1 day after (b)(satellite pass 4110). Ne is shown

for each panel at the lower panels. Black and blue dots show the model and observation respectively

(a) Total disappearance

(b) Partial disappearance

Total disappearance (a)

Partial disappearance(b)

Examples of the deviation of Te and Ne from the model for EQ1 in the

afternoon overshoot for EQ2. 2 days before EQ2 (a)(satellite pass, 4815), and 1 day after (b)(satellite pass 4856). Ne is shown for each panel at

the lower panels. Black and blue dots show the model and observation respectively

What can we find in Ionogram ( ground based ionosonde data) ?

1.Ionogam data at Manila suggests the contribution of westward Electric Field(EF). Reduction of h’F and night time reduction of foF2

2.Satellite data shows that longitudinal distribution of Te reduction is symmetric with epicenter,

which suggests that Electric field is directing one direction in these three cases.

………………………………………………………………………………..

Radial electric field ,which have been suggested so far produces plasma which rotates around epicenter. If we dare to explain as due to EF,there should be narrow +/- separation region near epicenter. This narrow charge separation region will be realized only in the low altitude region. In high altitude region ,this will not be seen.

How can we explain Te reduction observed with satellite(Ne behavior) , together with ionogram features?Key word: Westward electric field ?

Ratcliffe [1972]Plasma fountain

magnetic field line

Possible mechanism for Te reduction

1.Depression of EIA and at the same time h’F reduces

Dynamo Electric field is reduced

Ne reduces and the peak moves toward Equator

Eastward electric field by Natural wind

Westward Electric Field

Earthquake origin

2.Plasma is pushed down and this action supplies Ne ,and helps Ne to sustain late in the afternoon

Cartoon showing the mechanism of Te reduction and one evidence

1

2

EQ1

EQ2

EQ33

Plausible mechanism for Electric field generation

1.Large scale(more than 1000 km) wave is generated by latent hear flux at troposphere; Hagen and Forbes J.G.R.,2002 . Latent heat release ( Pulinets,cloud formation due to hydro cluster ions, quantitative study is needed)

2. Modification of E region dynamo electric field; England et al.,2006,G.R.L

3. Projection of the electric field to topside ionosphere along magnetic field line ； Immel et al.,G.R.L.,2006

 

Speculation !!!

Concluding Remarks

Our study shows that precursor of large earthquake seems to appear in the ionosphere. Although more work should be done by using existing resources with maximum efforts to confirm the effect , effort should be made to propose satellites which are purely dedicated to conduct the systematic earthquake study among disaster suffering countries. Micro/Mini satellites can contribute to study the effect of the earthquake on the ionosphere.Taiwan can play important role.

The study on EQ effects might open new field in the ionospheric research which has a long history of about 80 years since the discovery of ionosphere in 1920 ‘s (Lithosphere-Atmosphere-Ionosphere coupling).

Thank you !

Reduction of Te in afternoon overshoot is found prior to and after earthquake in low/mid latitude region.

1. Deviation of Te starts about 5 days prior to the earthquake and recovers to the original value after about 5 days. Deviation of Te seems to start earlier and recovery is slower as the magnitude of the earthquake increases.

2.The deviation ranges from 40-60 degrees to the west and 40-60 degrees to the east in longitude from the epicenter . There is a tendency that larger earthquake shows larger disturbed area.

3.The range of deviation extends from north to south with steep reduction in high latitude.

4. Ne does not change or shows small increase at the beginning of Te reduction, but later Ne reduces.

Satellite data

Te:Afternoon overshoot disappears and/or Te merges to afternoon overshoot in late afternoon

Ne:no clear change or slight reduction (see next summary)

Ionograms

Manila station: h’F reduces in all local times. Especially afternoon to night ,the height reduces from 400km to about 300 km.

Increase of NmF2 in the late afternoon(result of C oompression of plasma). Reduction of NmF2 at night . The minimum around 4 LT also reduces(direct effect of westward electric field).

Taipei station : When NmF2 increases at Manila,NmF2 at Taipei reduces.