yurdanur tulunay tolga yapıcı
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Effects of IMF B z reversals on the Ionospheric Critical Frequencies (f 0 F2) between 1975 and 1986. Yurdanur Tulunay Tolga Yapıcı Department of Aerospace Engineering, Middle East Technical University. Content. Introduction Objectives Datasets Criteria for “ Superposed Epoch” Results - PowerPoint PPT PresentationTRANSCRIPT
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COST 724 MCM, Antalya, TURKEY, 27-30/03/2006
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Effects of IMF Bz reversals on the Ionospheric Critical Frequencies (f0F2)
between 1975 and 1986
Yurdanur TulunayTolga Yapıcı
Department of Aerospace Engineering, Middle East Technical University
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COST 724 MCM, Antalya, TURKEY, 27-30/03/2006
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Content
Introduction Objectives Datasets Criteria for “Superposed Epoch” Results Conclusion Future Work
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COST 724 MCM, Antalya, TURKEY, 27-30/03/2006
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Introduction
IMF Bz component
Most of the features of the Earth’s magnetosphere and high latitude ionosphere
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COST 724 MCM, Antalya, TURKEY, 27-30/03/2006
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Objectives
Investigate the probable effects of IMF Bz on f0F2,
Search the role of geomagnetic conjugacy,
To validate the previously published results.
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COST 724 MCM, Antalya, TURKEY, 27-30/03/2006
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Datasets
Ionospheric Critical Frequencies:
AZ163 - KG24R,AZ163 - KG24R,
SO166SO166
Geomagnetic Index:
KpKp
Interplanetary Magnetic Field
Name CodeGeom. Lat.
Geom. Long.
Arkangelsk AZ163 60.38 N 117.54 E
Kerguelen Islands
KG24R 58.47 S 121.83 E
Sodankyla SO166 63.74 N 107.68 E
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Criteria for “SuperPosed Epoch”“SuperPosed Epoch”
The Geomagnetically quiet times:3 Hour Planetary Kp Index3 Hour Planetary Kp Index
1. Kp≤2+
Event Definition:IMF BIMF Bzz
1. Southward polarity change,2. | ΔIMF Bz | > 11 nT,3. Polarity should be same for 3 hours before the event4. Polarity should be same for 3 hours after the event
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Results – I
[Davis et al., 1997]
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Results – II
[Davis et al., 1997]
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Results – III (Control Curves)
[Tulunay et al., 2001]
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Results – IV (f0F2 distributions AZ163)
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Results – V (f0F2 distributions KG24R)
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Results –VI (f0F2 distributions SO166)
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Results – IV (AZ163)
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Results – V (SO166)
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Conclusion
ff00F2 variabilityF2 variability due to IMF BIMF Bzz reversals reversals have been studied.
Due to events, tendency of ~1 MHz~1 MHz decrease in δ(f0F2).
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Discussion – I
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Discussion – II
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Future Work
Develop a modelmodel of the ionospheric variabilityvariability under the IMF BIMF Byy and IMF B and IMF Bzz
dynamicsdynamics.
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Acknowledgement
Thanks to;
– TÜBİTAK ÇAYDAG– COST 724– Matthew Wild at the World Data Center
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References
Tulunay, Y., “Interplanetary magnetic field and its possible effects on the mid-latitude ionosphere II”, Annali di Geofisica, 37/2, (1994)
Tulunay, Y., “Interplanetary magnetic field and its possible effects on the mid-latitude ionosphere III”, Annali di Geofisica, 39/4 (1996)
Davis, J. D., Wild, M. N., Lockwood, M., Tulunay, Y., “Ionospheric and geomagnetic responses to changes in IMF Bz: a superposed epoch study”, Annales Geophysicae, 15, 217-230 (1997)
O. A. Troshichev, “Plasma pressure and the field aligned currents in the magnetosphere”, Advances in Space Sciences, 33, 729-736 (2005)
Nelson C. Maynard, “Coupling The Solar-Wind/IMF To The Ionosphere Through The High Latitude Cusps”, Surveys in Geophysics, 26: 255–280 (2005)
J. Merka, J. Safrankova, Z. Nemecek and J. Sımunek, “Magion-4 High-Altitude Cusp Study”, Surveys in Geophysics, 26: 57–69 (2005)
For Data:– http://spidr.ngdc.noaa.gov/spidr/index.jsp– World Data Centre at Rutherford– Matthew Wild
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Thanks for listening...