@Article{HajraTsurEcheGonz:2014:SoCyPh,
               author = "Hajra, Rajkumar and Tsurutani, Bruce T. and Echer, Ezequiel and 
                         Gonzalez, Walter Demetrio",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Jet 
                         Propulsion Laboratory (JPL) - California Institute of Technology} 
                         and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Relativistic electron acceleration during high-intensity, 
                         long-duration, continuous AE activity (HILDCAA) events: solar 
                         cycle phase dependences",
              journal = "Geophysical Research Letters",
                 year = "2014",
               volume = "41",
               number = "6",
                pages = "1876–1881",
                month = "Mar.",
             keywords = "HILDCAAs, magnetospheric relativistic electrons, chorus waves, 
                         high-speed streams, Alfv{\'e}n waves, solar cycle phases.",
             abstract = "High-intensity, long-duration, continuous AE activity (HILDCAA) 
                         intervals during solar cycle 23 (19952008) have been studied by a 
                         superposed epoch analysis. It was found that HILDCAA intervals 
                         order the solar wind velocity, temperature and density 
                         (characteristic of high-speed solar wind intervals), the polar cap 
                         potential, and various other geomagnetic indices well. The 
                         interplanetary magnetic field Bz is generally negative, and the 
                         Newell solar wind coupling function is high during HILDCAA events. 
                         The HILDCAA intervals are well correlated with an enhancement of 
                         magnetospheric relativistic (E\ >\ 2\ MeV) 
                         electron fluxes observed at geosynchronous orbit with a delay of 
                         ~1.5\ days from the onset of the HILDCAAs. The response of 
                         the energetic electrons to HILDCAAs is found to vary with solar 
                         cycle phase. The initial electron fluxes are lower for events 
                         occurring during the ascending and solar maximum (AMAX) phases 
                         than for events occurring during the descending and solar minimum 
                         (DMIN) phases. The flux increases for the DMIN phase events are 
                         >50% larger than for the AMAX phase events. Although the solar 
                         wind speeds during the DMIN phases were slightly higher and lasted 
                         longer than during the AMAX phases, no other significant solar 
                         wind differences were noted. It is concluded that electrons are 
                         accelerated to relativistic energies most often and most 
                         efficiently during the DMIN phases of the solar cycle. We propose 
                         two possible solar UV mechanisms to explain this solar cycle 
                         effect.",
                  doi = "10.1002/2014GL059383",
                  url = "http://dx.doi.org/10.1002/2014GL059383",
                 issn = "0094-8276",
                label = "self-archiving-INPE-MCTI-GOV-BR",
             language = "en",
           targetfile = "RevisedManuscript.pdf",
        urlaccessdate = "30 abr. 2024"
}