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@Article{SilvaSantBuchAlve:2018:NoHeFl,
               author = "Silva, Suzana de Souza e Almeida and Santos, J. C. and Buchner, J. 
                         and Alves, Maria Virginia",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Tecnol{\'o}gica Federal do Parana (UTFPR)} and {Max 
                         Planck Institut f{\"u}r Sonnensystemforschung (MPS)} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Nonlocal heat flux effects on temperature evolution of the solar 
                         atmosphere",
              journal = "Astronomy and Astrophysics",
                 year = "2018",
               volume = "615",
                pages = "A32",
                month = "July",
             keywords = "Sun: corona, Sun: atmosphere, magnetohydrodynamics (MHD).",
             abstract = "Context. Heat flux is one of the main energy transport mechanisms 
                         in the weakly collisional plasma of the solar corona. There, rare 
                         binary collisions let hot electrons travel over long distances and 
                         influence other regions along magnetic field lines. Thus, the 
                         fully collisional heat flux models might not describe transport 
                         well enough since they consider only the local contribution of 
                         electrons. The heat flux in weakly collisional plasmas at high 
                         temperatures with large mean free paths has to consider the 
                         nonlocality of the energy transport in the frame of nonlocal 
                         models in order to treat energy balance in the solar atmosphere 
                         properly. Aims. We investigate the impact of nonlocal heat flux on 
                         the thermal evolution and dynamics of the solar atmosphere by 
                         implementing a nonlocal heat flux model in a 3D 
                         magnetohydrodynamic simulation of the solar corona. Methods. We 
                         simulate the evolution of solar coronal plasma and magnetic fields 
                         considering both a local collision dominated and a nonlocal heat 
                         flux model. The initial magnetic field is obtained by a potential 
                         extrapolation of the observed line-of-sight magnetic field of 
                         AR11226. The system is perturbed by moving the plasma at the 
                         photosphere. We compared the simulated evolution of the solar 
                         atmosphere in its dependence on the heat flux model. Results. The 
                         main differences for the average temperature profiles were found 
                         in the upper chromosphere/transition region. In the nonlocal heat 
                         transport model case, thermal energy is transported more 
                         efficiently to the upper chromosphere and lower transition region 
                         and leads to an earlier heating of the lower atmosphere. As a 
                         consequence, the structure of the solar atmosphere is affected 
                         with the nonlocal simulations producing on average a smoother 
                         temperature profile and the transition region placed about 500 km 
                         higher. Using a nonlocal heat flux also leads to two times higher 
                         temperatures in some of the regions in the lower corona. 
                         Conclusions. The results of our 3D MHD simulations considering 
                         nonlocal heat transport supports the previous results of simpler 
                         1D two-fluid simulations. They demonstrated that it is important 
                         to consider a nonlocal formulation for the heat flux when there is 
                         a strong energy deposit, like the one observed during flares, in 
                         the solar corona.",
                  doi = "10.1051/0004-6361/201730580",
                  url = "http://dx.doi.org/10.1051/0004-6361/201730580",
                 issn = "0004-6361 and 1432-0746",
             language = "en",
           targetfile = "silva_nonlocal.pdf",
        urlaccessdate = "01 dez. 2020"
}


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