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The ELF Characterization of the Earth – Ionosphere Cavity

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Presentation on theme: "The ELF Characterization of the Earth – Ionosphere Cavity"— Presentation transcript:

1 The ELF Characterization of the Earth – Ionosphere Cavity
Yurdanur Tulunay[1], Yıldırım Bahadırlar[2], Emre Altuntaş[3], Ersin Tulunay[4],[2] [1] METU/ODTÜ, Dept. of Aerospace Eng., Ankara, Turkey [2] TÜBİTAK / MAM Institute of Information Technologies, Gebze Kocaeli, Turkey [3] METU/ODTÜ, Dept. of Aerospace Eng., Ankara, Turkey [4] METU/ODTÜ, Dept. of Electrical and Electronics Eng., Ankara, Turkey COST 724 MCM, Antalya, TURKEY, March 2006

2 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Content Introduction, Objectives & Experimental Sites, Data Analysis, Preliminary Results Future Study COST 724 MCM, Antalya, TURKEY, March 2006

3 Introduction- II SR occur in the Earth – Ionosphere Cavity
λ ≈ km Main source for variations: SR amplitudes: global lightning activity SR frequency: variations of thunderstorm (Nickolaenko and Rabinowicz, 1995; Nickolaenko et al., 1998). Fig. 1. Sources and Formation of Schumann Resonances Reference: COST 724 MCM, Antalya, TURKEY, March 2006

4 7.8; 14; 20; 26; 33; 39 and 45 Hz Introduction- I
Observed Frequencies: 7.8; 14; 20; 26; 33; 39 and 45 Hz COST 724 MCM, Antalya, TURKEY, March 2006

5 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Objectives - I SR Spectral characteristics: Resonant mode amplitude, A (mV^2) Center frequency, f (Hz), Q – Factor, f/width (unitless) COST 724 MCM, Antalya, TURKEY, March 2006

6 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Objectives - II Diurnal variations of SR Characteristics : Two measurement sites; GÖNEN (40o 06’ N 27o 38’ E) ŞARKÖY (40o 50’ N 27o 08’ E) COST 724 MCM, Antalya, TURKEY, March 2006

7 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Measurement Sites COST 724 MCM, Antalya, TURKEY, March 2006

8 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Measurement Sites Şarköy Gönen COST 724 MCM, Antalya, TURKEY, March 2006

9 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Data Analysis - I Raw data in time domain BP filtered October, 2004 Data FFT Analysis ... Sample Data: Şarköy Oct , 00:00 COST 724 MCM, Antalya, TURKEY, March 2006

10 Data Analysis - II 6 Lorenzian functions of the form;
Lorentz Curve Fit (Price et al. 2004) COST 724 MCM, Antalya, TURKEY, March 2006

11 Results – I (Diurnal var. of each 4 Mode Power)
COST 724 MCM, Antalya, TURKEY, March 2006

12 Results – II (Diurnal var. of each Mode Peak Freq.s)
COST 724 MCM, Antalya, TURKEY, March 2006

13 Results – III (Diurnal var. of each 3 Mode Q-Fac.)
COST 724 MCM, Antalya, TURKEY, March 2006

14 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Conclusions - I Presented the SR Parameters observed in Turkey, One month period (October 2004). The three parameters of the SR spectra amplitude, frequency and damping obtained fitting the data with 6 Lorenzian curves. COST 724 MCM, Antalya, TURKEY, March 2006

15 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Conclusions - II The power (amplitude2) variations during the day maximum at 1400 LT, frequency power The frequency variations; complex charact., in agreement with (Price et al and SHatori 1996) Q-Factor variations; complex characteristics, in agreement with (Price et al and SHatori 1996) COST 724 MCM, Antalya, TURKEY, March 2006

16 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Future Work Turkish SR Results will be: Input METU NN Neural Network Forecasting of Future SR Parameters COST 724 MCM, Antalya, TURKEY, March 2006

17 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
Acknowledgement Thanks to COST 724 TUBITAK MAM TUBITAK ÇAYDAG COST 724 MCM, Antalya, TURKEY, March 2006

18 COST 724 MCM, Antalya, TURKEY, 27-30 March 2006
References [1] Price C., Melnikov A., Diurnal, seasonal and inter-annual variations in the Schumann resonance parameters, Journal of Atmospheric and Solar- Terrestrial Physics, Vol 66, pp. 1179– 1185, 2004 [2] Resonances in Earth-Ionosphere Cavity, Nickolaenko A.P., Hayakawa M., Kluver Academin Publishers, Dordrecht/Boston/London, 2002. [3] SHatori, G., Monitoring Schumann resonances—II. Daily and seasonal frequency variations. Journal of Atmospheric and Terrestrial Physics 5, 1483–1488., 1996 [4] Sentman, D.D., Fraser, B.J., Simultaneous observations of Schumann resonances in California and Australia: evidence for intensity modulation by the local height of D region. Journal of Geophysical Research 96, 15973–15984., 1991. [5] COST 724 MCM, Antalya, TURKEY, March 2006


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