Slide 1

THE AURORAL EMISSIONS AND THE ELECTRON PRECIPITATION UNDER DIFFERENT GEOMAGNETIC CONDITIONS DURING RECURRENT SOLAR WIND STREAM Guineva V. 1, Despirak I. 2, Werner R., Trondsen E. 3, Honary F. 4, Marple S. 4, Dahle K. 5, Stauning P. 6 1)Solar-Terrestrial Influences Laboratory, Bulgarian Academy of Sciences, Stara Zagora Department, 6000 Stara Zagora, P.O.Box 73, Bulgaria 2)Polar Geophysical Institute, Apatity, Russia 3)University of Oslo, Department of Physics, Norway 4)Lancaster University, Department of Communications Systems, UK 5)Andya Rocket Range, Andenes, Norway 6)Danish Meteorological Institute, Copenhagen, Denmark Slide 2 Observation instruments All-Sky Imager (ASI): ARR, Andenes, Norway (69.3N, 16.03E); 5577 and 6300 emissions; 10 s time resolution; 180 field of view in a 512x512 matrix; All-Sky Imager (ASI): Auroral Observatory, Longyearbyen, Svalbard (78.20N, 15.83E); Andenes Imaging Riometer for Ionospheric Studies (AIRIS): absorption of cosmic noise at 38.2 MHz by 49 beams (7x7 area) every second (electrons with energies 10x100keV and deposition heights centered at about 90 km); Imaging Riometer for Ionospheric Studies (IRIS): Kilpisjrvi, Finland (69.05N, 20.79E); 64-beam Imaging Riometer and magnetometer at Longyearbyen, 38.2 MHz absorption; Andenes Magnetometer: registers the magnetic field components every second. Simultaneous observations from several instruments are used: Slide 3 Projected fields of view of ASI and IRIS Instruments projected fields of view: Longyearbyen All-Sky Imager 6300 (emission altitude 250 km) 5577 (emission altitude 120 km) Andenes All-Sky Imager 6300 (emission altitude 250 km) 5577 (emission altitude 120 km) Andenes Imaging Riometer (AIRIS) (90 km reference altitude) Imaging Riometer at Kilpisjrvi (IRIS) (90 km altitude) Imaging Riometer at Longyearbyen (90 km altitude) Slide 4 Examined periods during 2005/2006 season 3-4.11.2005 the most disturbed days in November (D1 and D2); 7-8.11.2005 quiet period; 26.1.2006 most disturbed day in the month (D1), all instruments had functioned Slide 5 IMF, solar wind parameters Slide 6 Temporal development ASI keograms along the 103.8E geomagnetic meridian IRIS keograms along the 103.8E geomagnetic meridian, 65.2-66.8MLAT IRIS absorption beam 25 at 38.2 MHz Total magnetic field and its H, Z and D components at Andenes 6300 65-74.2 MLAT 5577 68.8-72 MLAT 3-4.11.2005 15:50-5:40 UT 7-8.11.2005 15:30-5:50 UT Slide 7 Spatial distributions of the emissions and particles 3.11.2005 18-19 UT 3.11.2005 22-23 UT 7.11.2005 22-23 UT 1 min. interval images 5577 6300 Kilpisjrvi IRIS absorption images Andya all-sky images Slide 8 UTCorrelation between:Zone IZone IIZone III 18:00 21:00 3.11.2005 I 5577 -I 6300 Central point0.8190.7070.913 Mean value0.9670.8460.979 I 5577 - Absorption0.6780.3060.301 I 6300 - Absorption0.6440.2510.270 21:00 24:00 3.11.2005 I 5577 -I 6300 Central point-0.450.7530.936 Mean value-0.470.8960.984 I 5577 - Absorption0.8120.580.815 I 6300 - Absorption0.5050.420.665 IIIIII I II III IIIIII III Slide 9 UTMean ratios:Zone IZone IIZone III 18:00 21:00 3.11.2005 I 6300 /I 5577 Central point0.4070.1980.176 Mean value0.3650.2260.208 Absorption/I 5577 0.211.850.845 Absorption/I 6300 0.0710.6160.317 21:00 24:00 3.11.2005 I 6300 /I 5577 Central point0.40.260.33 Mean value0.440.240.35 Absorption/I 5577 -0.1361.5564.357 Absorption/I 6300 -0.0120.5840.858 I I II III Slide 10 UTCorrelation between I 5577 - I 6300 : 18:00 21:00 7.11.2005 Central point0.8 Mean value0.888 21:00 24:00 7.11.2005 Central point0.749 Mean value0.752 Slide 11 UTMean ratios: 18:00 21:00 7.11.2005 I 6300 /I 5577 Central point0.508 Mean value0.56 Absorption/I 5577 0.147 Absorption/I 6300 0.023 21:00 24:00 7.11.2005 I 6300 /I 5577 Central point0.365 Mean value0.41 Absorption/I 5577 0.343 Absorption/I 6300 0.063 Slide 12 Summary The behaviour of the 5577 and 6300 intensities and the absorption at 38.2 MHz in some cases under different conditions during substorms and under quiet conditions, during the passage of recurrent high energy solar wind stream is examined; During substorms, the energy spectrum of the precipitating particles is enhanced in the part of the higher energies; I 6300 /I 5577 becomes 1.5-2 times smaller during substorms (~0.2) than in quiet conditions (~0.4-0.5); I 6300 and I 5577 correlate very well regardless of the conditions. Slide 13 Acknowledgments: The work was supported by the European Unions 6th Framework Program within the ALOMAR eARI (22_VeGi and 40_VeGi) Projects. We are thankful for the data originated from the Imaging Riometer for ionospheric Studies (IRIS), operated by the Department of Communications Systems at Lancaster University (UK) in collaboration with the Sodankyl Geophysical Observatory, and funded by the Particle Physics and Astronomy Research Council (PPARC). The authors are grateful to Truls Lynne Hansen of the Troms Geophysical Observatory, University of Troms, Norway, for providing magnetometer data. We thank to Kjell Henriksen Observatory and Danish Meteorological Institute for giving us the data from the 64-beam imaging riometer and the magnetometer at Longyearbyen. Slide 14 Thanks for the attention!