STUDY TITLE: SOLAR MICROFLARES AND NETWORK DYNAMICS - RELEVANCE FOR CORONAL HEATING
STUDY TEAM : J. Rybak (choc@astro.sk), P. Gomory, A. Veronig, M. Temmer, S. Stoiser

Science Case:

This proposal merges together attempts to observe two kinds of solar structures -
solar microflares and supergranular network - which are planned to be investigated 
to address common open questions on their relevance for the heating and 
dynamics of the solar corona.

Due to their small sizes and fast dynamics microflares need analysis demanding 
high spatial resolution observations combined with good temporal cadence. 
Our objective is to analyse the dynamics and plasma evolution during microflares 
by studying the chromospheric response to electron beam and/or conductive heating 
together with the transition region and coronal response combined with X-ray 
spectral analysis. The comparison of these observational data with theoretical 
predictions in the frame of electron-beam-driven and conductively driven 
chromospheric evaporation for individual microflares can help us to better 
understand: a) whether non-thermal electrons are present in microflares which 
hints at magnetic reconnection as the underlying physical process, b) how much 
plasma is brought into the corona by microflares, c) which process dominates 
the mass transport, d) how much energy which is available for the heating of the 
corona is deposited during microflares.  

Supergranular network is clearly related to the heating of the corona
as well. On the other hand its close relation to the underlying layers is 
obvious today. Photospheric and chromospheric layers are planned to be investigated 
to identify the most probable physical mechanisms responsible for the energy 
transfer and dynamics of the solar corona above the chromospheric network. Our 
previous results indicate presence of downward propagating waves in/above the 
chromospheric network. These results led to the assumption that reconnection of 
the magnetic field lines should be the dominant mechanism to heat the solar corona 
above the particular chromospheric network. In contrast, findings of other authors 
show evidence of propagating intensity oscillations spreading out from the 
photosphere to the corona and therefore prefer alternative heating mechanism of 
the corona. To clarify these findings new measurements are necessary for better 
identification of the heating mechanism. We expect that time series of the 
speckle-reconstructed DOT filtergrams taken simultaneously with the Hinode/EIS 
spectra and the supporting Hinode/SOT and XRT data will provide an excellent 
material to study the properties of the mentioned targets. 

More details: campaign web page: http://www.astro.sk/~choc/open/07_dot/07_dot.html

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Predicted count rates: Active region/Quiet sun - 10s.

Note: we expect higher count rates than counts obtained for the quiet sun listed below 
when observing the network emission.

Wavelength      c/p     Ion               Total counts for exposure (per pixel)
                                active region / quiet sun   
192.82*		c	Ca XVII		  572 /    0
195.12*		c	Fe XII		 4240 /  138
256.32*		c	He II		  247 /   47

185.21	        p	Fe VIII         
275.35	        p	Si VII            117 /   12
184.54	        p	Fe X              235 /   13
196.54	        p	Fe XIII           336 /    4
284.16          p       Fe XV            1266 /    6
192.04          p       Fe XXIV           138 /   
202.04          p       Fe XIII           730 /   17
203.83          p       Fe XIII           458 /    8

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