@Article{RemyaTsuRedLakHaj:2015:EMWaCo,
               author = "Remya, B. and Tsurutani, Bruce T. and Reddy, V. A. and Lakhina, G. 
                         S. and Hajra, Rajkumar",
          affiliation = "{Indian Institute of Geomagnetism} and {California Institute of 
                         Technology} and {Indian Institute of Geomagnetism} and {Indian 
                         Institute of Geomagnetism} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Electromagnetic cyclotron waves in the dayside subsolar outer 
                         magnetosphere generated by enhanced solar wind pressure: EMIC wave 
                         coherency",
              journal = "Journal of Geophysical Research: Space Physics",
                 year = "2015",
               volume = "120",
               number = "9",
                pages = "7536--7551",
                month = "Sept.",
             keywords = "cyclotron waves, EMIC, pitch angle scattering, wave coherency.",
             abstract = "Electromagnetic ion (proton) cyclotron (EMIC) waves and whistler 
                         mode chorus are simultaneously detected in the Earth's dayside 
                         subsolar outer magnetosphere. The observations were made near the 
                         magnetic equator 3.1-1.5 magnetic latitude at 1300 magnetic local 
                         time from L = 9.9 to 7.0. It is hypothesized that the solar wind 
                         external pressure caused preexisting energetic 10-100 keV protons 
                         and electrons to be energized in the T\⊥ component by 
                         betatron acceleration and the resultant temperature anisotropy 
                         (T\⊥>TĄ) formed led to the simultaneous generation of both 
                         EMIC (ion) and chorus (electron) waves. The EMIC waves had maximum 
                         wave amplitudes of 6 nT in a 60 nT ambient field B0. The observed 
                         EMIC wave amplitudes were about 10 times higher than the usually 
                         observed chorus amplitudes (0.1-0.5 nT). The EMIC waves are found 
                         to be coherent to quasi-coherent in nature. Calculations of 
                         relativistic 1-2 MeV electron pitch angle transport are made using 
                         the measured wave amplitudes and wave packet lengths. Wave 
                         coherency was assumed. Calculations show that in a 25-50 ms 
                         interaction with an EMIC wave packet, relativistic electron can be 
                         transported 27 in pitch. Assuming dipole magnetic field lines for 
                         a L = 9 case, the cyclotron resonant interaction is terminated ±20 
                         away from the magnetic equator due to lack of resonance at higher 
                         latitudes. It is concluded that relativistic electron anomalous 
                         cyclotron resonant interactions with coherent EMIC waves near the 
                         equatorial plane is an excellent loss mechanism for these 
                         particles. It is also shown that E > 1 MeV electrons cyclotron 
                         resonating with coherent chorus is an unlikely mechanism for 
                         relativistic microbursts. Temporal structures of 30 keV 
                         precipitating protons will be 2-3 s which will be measurable at 
                         the top of the ionosphere.",
                  doi = "10.1002/2015JA021327",
                  url = "http://dx.doi.org/10.1002/2015JA021327",
                 issn = "2169-9402",
             language = "en",
        urlaccessdate = "27 abr. 2024"
}