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 6437 Unknown 3,Injured 43792, 10 chouen (80 chouenn)

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

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-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 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 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. 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

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

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

２．Ｒｅｓｕｌｔｓ ｆｒｏｍ ＨＩＮＯＴＯＲＩ satellite Launched from KSC in 1981 February Inclination;31 degrees Height;576-644 km Electron Density & Temperature 1981/2/1-1982/6/30/ Electron Temperature Probe(Te) Hirao, K. and K.- I.Oyama, J.Geomag Geoelectr . ,22,239-402,1970. Impedance Probe (Ne) Oya,H.,T.Takahashi,and S.Watanabe,, J.Geomag.Geoelectr.,38,111-124,1986.

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.

(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

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

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

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.

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

Cartoon showing the mechanism of Te reduction and one evidence 1 EQ1 EQ2 2 3 EQ3

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.,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

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.

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.