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VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260309T054201Z
UID:https://www.mps.mpg.de/events/13642/4914875
DTSTART:20180419T090000Z
DTEND:20180419T100000Z
CLASS:PUBLIC
CREATED:20180411T082054Z
DESCRIPTION: A giant solar filament was visible on the solar surface betwee
 n 8-23 November 2011. The filament stretched over more than half a solar d
 iameter. Multi-wavelength data from the SDO instrument AIA (171\, 193\, 30
 4\, and 211 Å) were used to examine counter-streaming flows within the sp
 ine of the filament. H-alpha images from the Kanzelhöhe Solar Observatory
  provided context information. We applied local correlation tracking (LCT)
  to a two-hour AIA time series from 16 November 2011 to derive horizontal 
 flow velocities of the filament. To enhance the contrast of the AIA images
 \, we employed noise adaptive fuzzy equalization (NAFE)\, allowing us to i
 dentify and quantify counter-streaming flows in the filament. We detected 
 counter-streaming flows in the filament\, visible in the time-lapse movies
  of all the examined AIA wavelength bands. Using time-lapse movies we foun
 d that these persistent flows lasted for at least two hours. Furthermore\,
  by applying LCT to the images we clearly determined counter-streaming flo
 ws in time series of 171 Å and 193 Å images. In the 304 Å wavelength ba
 nd we found only minor indications for counter-streaming flows with LCT\, 
 while in the 211 Å wavelength band the counter-streaming flows are not de
 tectable. The average horizontal flows reach mean flow speeds of 0.5 km/s.
  The highest horizontal flow speeds are identified in the 171 Å band with
  flow speeds of up to 2.5 km/s. The results are averaged over a time serie
 s of 90 min. Because the LCT sampling window has a finite width\, spatial 
 degradation cannot be avoided\, leading to lower estimates of the flow vel
 ocities as compared to feature tracking or Doppler measurements. The count
 er-streaming flows cover about 15-20% of the whole area of the EUV filamen
 t channel and are located in the central part of the spine. In conclusion\
 , we confirm counter-streaming flows are omnipresent also in giant quiet-S
 un filaments.\nSpeaker: Andrea Dierke
LAST-MODIFIED:20260220T073710Z
LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) broadcasted on MP
 S\, Room: Aquila\, Bootes\, Cygnus
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Counter-streaming Flows of a Giant Solar
  Filament as Observed in the Extreme Ultraviolet (A. Dierke)
URL;VALUE=URI:https://www.mps.mpg.de/events/13642/4914875
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