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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260912T075345Z
UID:https://www.mps.mpg.de/events/18257/7840830
DTSTART:20190411T090000Z
DTEND:20190411T100000Z
CLASS:PUBLIC
CREATED:20190405T094526Z
DESCRIPTION:The Astronomical Observatory of the Coimbra University has a co
 llection of solar observations on a daily basis\, since 1926. We obtain re
 gular observations of the full solar disk using a classical spectroheliogr
 aph\, in the spectral lines of Ca II and Halpha (this one only after 1989)
 . Until 2007 the acquisition was based on photographic plates and films. T
 his data is digitized and public. Since then\, a 12-bit CCD camera is oper
 ational. Nowadays\, the local weather conditions allows observations in mo
 re than 300 days/year. This data is\, particularly\, suitable for solar cy
 cle studies. In this talk\, we briefly present a history of these observat
 ions\; we discuss recent results using the data\; and we present some pers
 pectives for the near future. The ubiquitous presence of small magnetic el
 ements in the Quiet Sun represents a prominent coupling between the photos
 phere and the upper layers of the Sun’s atmosphere. Small magnetic eleme
 nt tracking has been widely used to study the transport and diffusion of t
 he magnetic field on the solar photosphere. From the analysis of the displ
 acement spectrum of these tracers\, it has been recently agreed that a reg
 ime of super-diffusivity dominates the solar surface. In this talk we will
  focus on the analysis of the bipolar magnetic pairs in the solar photosph
 ere and their diffusion properties\, using a 25-h dataset from the HINODE 
 satellite. Interestingly\, the displacement spectrum for bipolar couples b
 ehaves similarly to the case where all magnetic pairs are considered. We a
 lso measure\, from the same dataset\, the magnetic emergence rate of the b
 ipolar magnetic pairs and we interpret them as the magnetic footpoints of 
 emerging magnetic loops. The measured magnetic emergence rate is used to c
 onstrain a simplified model that mimics the advection on the solar surface
  and evolves the position of a great number of loops\, taking into account
  emergence\, reconnection and cancellation events. In particular we comput
 e the energy released by the reconnection between different magnetic loops
  in the nano-flares energy range. Our model gives a quantitative estimate 
 of the energy released by the reconfiguration of the magnetic loops in a q
 uiet Sun area as a function of height in the solar atmosphere\, from hundr
 eds of Km above the photosphere up to the corona\, suggesting that an effi
 ciency of ~10% in the energy deposition might sustain the million degree c
 orona.\nVortragende(r): João Fernandes 
LAST-MODIFIED:20260220T073337Z
LOCATION:University of Coimbra\, Portugal (broadcasted at MPS)\, Raum: Audi
 torium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The Sun from Coimbra: history\, recent r
 esults and perspectives (João Fernandes)
URL;VALUE=URI:https://www.mps.mpg.de/events/18257/7840830
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