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The Space Weather Week Monique Pick LESIA, Observatoire de Paris 13-17 November 2006
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Interest of radio observations for CMEs –More particularly forcast those reaching the Earth –Proxies (Halo) –Future plans Web site ( http://secchirh.obspm.fr) –More particularly forcast those reaching the Earth –iesFuture plans
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Radio emissions from the corona and inner heliosphere JLB / 2002.04.24 / ST-21 / EGS-Nice - 3 -
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Coronal Mass Ejections Fast and narrow CMES associated with short duration emissions (electron beams, typeIII). Fast and large CMEs associated with complex radio emissions at meter wavelengths lasting >> 10 minutes. Also associated with flares Radio detects these events above the solar limb and on-disk
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Radio complex events over a large frequency range Similarity 1MHz and 1-3 GHz Reiner et al. (2001,02) Long duration >20 min Origin in low corona Flare/CME events
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CME and Complex radio events 26 complex radio events 20 events associated with shocks ( type II-like features) 26 associated with CMEs (also Cane, 2002); 17 halo CMEs; 7 Width> 100°. (reach Earth) *Emitting radio sources (NRH meter λ) complex and spread over a large volume; onset of new sources * Coronal processes, involving multiple B system participate in the eruption. Maia and Pick, ApJ, 609, 1082 2004 Pick et al, AdSR 35 1976 2005
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Halo CME May 02 1998: Disk observations Pohjolainen et al., 2001
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October 28 2003 Halo CME CME RH Nançay C2 LASCO Radio imaging at 164 Mhz traces the early CME development and the regions of B interaction The coronal wave and the CME encompasses most of the solar disk (10 min)
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October 28 2003 Halpha Moreton wave
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Moreton waves
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Fast progression in latitude Full extend: < 10 min Successive loop interactions Super-alfvenic disturbance CME proxies Angular extend Speed (3000km/s) On-disk and limb CMEs E W N S Duration (lateral spread) Indication on V
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A new web site for radio monitoring A. Bouteille, R. Romagnan M. Pick, M. Maksimovic, J. L. Bougeret, A. Lecacheux, (LESIA) C. Alissandrakis, X. Moussas, A. Hillaris (Greece) A. Vourlidas, R. Howard (NRL) CMEs (V, W, PA) Goal: one radio spectrum in combining data from different spectrographs (large freq. Range) - Nançay Radioheliograph (metric λ) - SECCHI CME summary (in near future) -Real time -NRH imaging link with the SWB, Royal ObservatoryNRH imaging link with the SWB, Royal Observatory http://secchirh.obspm.fr/
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+ + Pair of long duration radio emissions Post eruptive emissions of long duration dm-dam λ (NRH site) km bandwidth 300kHz drifting, Widely ≠ frequency range. Similar temporal, spectral profiles Slow drifting BW 300KHz PFFS extrapolation
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Pairs of two continua not connected If first harmonic emission, velocity of expansion 485 km/s and mean altitude of 5Rs near onset; CME has reached altitude of 6Rs (fp×r = 20kHz 1AU);13 UT 15 Rs If plasma emission, kilometric source lower density than the source of metric continuum Suggestion: Destabilization of loop system (Km) created by B interaction between expanding CME and neighbouring loops Electrons radiating low freq continuum originates in region of interaction (sporadic m activity) + Low frequency continuum
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Concluding remarks Proxies –improve the characteristics : V, lateral expansion (statistical study) –Investigation on polarization Futur work –S-Waves (STEREO) –Link with other sites –Survey SOHO 1997-to-day, in progress –Spectograph page > 16 hours –Includes spectral frequency range toward microwave
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End
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Limb events Angular development < 10 min
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Electrons trace the expansion of the arch system(~2500 km/sec) Coronal wave develops along flank of CME In lateral expansion 164 MHz
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in IP space f ≈ R -1 f p = 9 √ N e kHz cm -3 Radio emissions from the inner heliosphere JLB / 2002.04.24 / ST-21 / EGS-Nice - 23 -
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