Forthcoming SIDC Seminars

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Meeting Time : Normally Thursdays from 2pm to 3pm, see table otherwise
Room : Normally TV-Room, see table otherwise
Date & TimeLocationSpeakerAffiliationTitleRemarksAbstract
2010-09-10 at 14:00:00 Meridian Room TBC Dipankar Banerjee Indian Institute of Astrophysics, Bangalore, India Propagating Waves in the Polar Coronal Holes Note the unusual day and time! Display the abstractWith modern imaging and spectral instruments observing in the visible, EUV, X-ray and radio wavelengths, the detection of oscillations in the solar outer atmosphere has become a routine event. These oscillations are considered to be the signatures of a wave phenomenon and are generally interpreted in terms of magnetohydrodynamic (MHD) waves. I will present some new observational report on the detection of accelerating waves in the polar regions of the Sun. These observations are taken from Hinode and SoHO. I will discuss if these waves can be important for the acceleration of the solar wind. Interpretation in terms of flows versus waves will be also discussed. Finally I will briefly discuss on the Aditya project. Recently Inidan Space Research Organisation (ISRO) have approved a coronagrapgh payload to be flown on Aditya mission.
2010-09-14 at 14:30:00 TV Room Leif Svalgaard Calibration of Sunspot Numbers Display the abstractWaldmeier [1971] found a very tight relationship between the F10.7 solar radio flux and the sunspot number and suggested using the flux for an objective calibration of the sunspot number. He suggested that if this relationship changed later on, the sunspot number should be re-calibrated, assuming that the calibration must have drifted with time. I repeat his analysis using data up to the present and it is, indeed, clear that the relationship has changed significantly. This could be due to a drift of the calibration or to a secular change in the visibility of sunspots, or both.
If you want to give a seminar, or if you want more info, please send an e-mail to Andreï Zhukov