1. 16:20-16:40 Nov.3 2008 Cheng Kung University,Taiwan
Oyama et al, J.Geophys.Res.,2008
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
Great Hanshin-Awaji Earthquake M.7.3 Jan 17,1995 Death Unknown 3,Injured 43792, 10 chouen (80 chouenn)

2. 2. Results from Japanese Hinotori satellite
This paper stresses that new academic field is being opened regarding the effects of EQ on ionosphere
　　　　　　　 CONTENT
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

3. Cloud ,Temperature rise :recent remote sensing satellites
The space projects where the ionospheric observation and the earthquake precursors were studied
Intercosmos-Bulgaria 1300 – 1982
Salyut
Meteor
Cosmos
ISIS-2 – 1971
Activny -(Intercosmos-24) -1989
TOPEX/Poseidon
GEOS-1 and
MIR Space Station
DE-2
Quakesat
DEMETER
HINOTORI
Alouette
Cosmos
OGO
OVI
ISIS-2 – 1971
АЕ-С -1973
GEOS-1 and
Intercosmos-19 – 1979 Aureol-3 –1981
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

4. 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.
Dynamics
Mixture of electrons, ions of various species such as NO+ and O+,and neutral particles
Chemical Reaction
Temperatures are defined for these three particles such as Te,Ti and Tn
1/2m〈v2〉= 3/2kT
Te is most sensitive

5. 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
( P.S.S., Ann.Geophys, J.G.R.)
This is the history how I was convinced the existence of the effects of earthquake on ionosphere

6. Study of the effect of the Earthquake M≥6.5 (USGS)
(EQ1) 1981/11/22 15:05 N18.75 E km Ms6.7
(EQ2) 1982/1/11 6:10 N13.75 E km Ms7.4
(EQ3) 1982/1/24 6:08 N14.09 E km Ms6.6

7. ２．Ｒｅｓｕｌｔｓ ｆｒｏｍ ＨＩＮＯＴＯＲＩ satellite
Launched from KSC in 1981 February
Inclination;31 degrees
Height; km
Electron Density & Temperature
1981/2/1-1982/6/30/
Electron Temperature Probe(Te) Hirao, K. and K.- I.Oyama, J.Geomag Geoelectr . ,22, ,1970.
Impedance Probe (Ne) Oya,H.,T.Takahashi,and S.Watanabe,, J.Geomag.Geoelectr.,38, ,1986.

8. Solar flux variation of Te
Northern winter
Solar flux variation of Te
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.

9. (a) Total disappearance
(b)　Partial disappearance
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

10. Partial disappearance(b)
Total disappearance
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

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

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

16. Possible mechanism for Te reduction
Earthquake origin
Dynamo Electric field is reduced
Westward Electric Field
1.Depression of EIA and at the same time h’F reduces
Ne reduces and the peak moves toward Equator
2.Plasma is pushed down and this action supplies Ne ,and helps Ne to sustain late in the afternoon
Ratcliffe [1972]
Plasma
fountain
magnetic
field line
Eastward electric field by Natural wind

17. Cartoon showing the mechanism of Te reduction and one evidence1
EQ1
EQ2 2 3
EQ3

18. Plausible mechanism for Electric field generation
Speculation !!!
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., 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

19. 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 !

21. 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 degrees to the west and 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.

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