@Article{DasOphEvaLoeGom:2011:EvPiCo,
               author = "Das, Indrajit and Opher, Merav and Evans, Rebekah and Loesch, 
                         Cristiane and Gombosi, Tamas I.",
          affiliation = "George Mason Univ, Fairfax, VA 22030 USA and Boston Univ, Dept 
                         Astron, Boston, MA 02215 USA and George Mason Univ, Fairfax, VA 
                         22030 USA and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and Univ Michigan, Ann Arbor, MI 48109 USA",
                title = "Evolution of piled-up compressions in modeled coronal mass 
                         ejection sheaths and the resulting sheath structures",
              journal = "Astrophysical Journal",
                 year = "2011",
               volume = "729",
               number = "2",
                pages = "AR 112",
                month = "Mar.",
             keywords = "IN-SITU SIGNATURES, MAGNETIC CLOUDS, SOLAR-WIND, 
                         MAGNETOHYDRODYNAMIC MODEL, SHOCKS DRIVEN, 1 AU, EXPANSION, 
                         ACCELERATION, SIMULATIONS, HELIOSPHERE. magnetohydrodynamics 
                         (MHD), Sun: corona, Sun: coronal mass ejections (CMEs).",
             abstract = "We study coronal mass ejection (CME)-driven shocks and the 
                         resulting post-shock structures in the lower corona (2-7 R(circle 
                         dot)). Two CMEs are erupted by modified Titov-Demoulin (TD) and 
                         Gibson-Low (GL) type flux ropes (FRs) with the Space Weather 
                         Modeling Framework. We observe a substantial pile-up of density 
                         compression and a narrow region of plasma depletion layer (PDL) in 
                         the simulations. As the CME/FR moves and expands in the solar wind 
                         medium, it pushes the magnetized material lying ahead of it. 
                         Hence, the magnetic field lines draping around the CME front are 
                         compressed in the sheath just ahead of the CME. These compressed 
                         field lines squeeze out the plasma sideways, forming PDL in the 
                         region. Solar plasma being pushed and displaced from behind forms 
                         a strong piled-up compression (PUC) of density downstream of the 
                         PDL. Both CMEs have comparable propagation speeds, while GL has 
                         larger expansion speed than TD due to its higher initial magnetic 
                         pressure. We argue that high CME expansion speed along with high 
                         solar wind density in the region is responsible for the large PUC 
                         found in the lower corona. In case of GL, the PUC is much wider, 
                         although the density compression ratio for both the cases is 
                         comparable. Although these simulations artificially initiate 
                         out-of-equilibrium CMEs and drive them in an artificial solar wind 
                         solution, we predict that PUCs, in general, will be large in the 
                         lower corona. This should affect the ion profiles of the 
                         accelerated solar energetic particles.",
                  doi = "10.1088/0004-637X/729/2/112",
                  url = "http://dx.doi.org/10.1088/0004-637X/729/2/112",
                 issn = "0004-637X and 1538-4357",
             language = "en",
           targetfile = "0004-637X_729_2_112.pdf",
        urlaccessdate = "03 maio 2024"
}