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SUMMARY:Quantifying Poynting Flux in the Quiet Sun Photosphere Using Obser
 vations and Simulations
DTSTART;VALUE=DATE-TIME:20230510T071500Z
DTEND;VALUE=DATE-TIME:20230510T073000Z
DTSTAMP;VALUE=DATE-TIME:20240704T115654Z
UID:indico-contribution-317@meetings.aip.de
DESCRIPTION:Speakers: Denis Tilipman (University of Colorado\, Boulder\; N
 ational Solar Observatory (NSO))\nThe solar chromosphere and corona are he
 ated by the dissipation of magnetic energy that emerges from the photosphe
 re. The outward flux of magnetic energy\, or Poynting flux\, is therefore 
 important to understand in both qualitative and quantitative terms. It can
  be computed by taking a cross product of electric and magnetic fields\, a
 nd in ideal MHD conditions it can be expressed in terms of magnetic field 
 and plasma velocity. There are existing estimates of Poynting flux in acti
 ve regions and plages\, but the quiet Sun (QS) remains a challenging targe
 t due to resolution effects and polarimetric noise. However\, with upcomin
 g DKIST capabilities\, these estimates will become more feasible than ever
  before.\n\nHere we present our findings from studying QS Poynting flux in
  Sunrise/IMaX observations and MURaM simulations. Since this problem has n
 ot been comprehensively approached before\, and due to the aforementioned 
 challenges of QS observations\, we explore and evaluate multiple methods f
 or computing Poynting flux. For transverse velocities\, we try two inversi
 on methods – a classic correlation tracking approach FLCT and a neural n
 etwork based method DeepVel – and show DeepVel to be the more suitable m
 ethod in the context of small-scale QS flows. Further\, we investigate the
  effect of magnetic field azimuthal ambiguity on Poynting flux estimates\,
  and we describe a new method for azimuth disambiguation. Finally\, we use
  two methods for obtaining the electric field. The first method relies on 
 idealized Ohm's law\, whereas the second is a state-of-the-art inductive e
 lectric field inversion method PDFI\\_SS.\n\nWe compare the resulting Poyn
 ting flux values with theoretical estimates for chromospheric and coronal 
 energy losses and find that some\, but not all\, of Poynting flux estimate
 s are sufficient to match the energy losses. Using MURaM simulations\, we 
 show that photospheric Poynting fluxes vary with optical depth\, and that 
 there is an observational bias that results in underestimated Poynting flu
 xes due to unaccounted shear term contribution.\n\nhttps://meetings.aip.de
 /event/24/contributions/317/
LOCATION:Haus H\, Telegrafenberg
URL:https://meetings.aip.de/event/24/contributions/317/
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