author = "Santos, Angela Machado dos and Abdu, Mangalathayil Ali and Souza, 
                         Jonas Rodrigues de and Sobral, Jos{\'e} Humberto Andrade and 
                         Batista, Inez Staciarini",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais 
                title = "Disturbance zonal and vertical plasma drifts in the Peruvian 
                         sector during solar minimum phases",
              journal = "Journal of Geophysical Research A: Space Physics",
                 year = "2016",
               volume = "121",
               number = "3",
                pages = "2503--2521",
                month = "Mar.",
             keywords = "electric field, ionospheric drifts, magnetic storms.",
             abstract = "In the present work, we investigate the behavior of the equatorial 
                         F region zonal plasma drifts over the Peruvian region under 
                         magnetically disturbed conditions during two solar minimum epochs, 
                         one of them being the recent prolonged solar activity minimum. The 
                         study utilizes the vertical and zonal components of the plasma 
                         drifts measured by the Jicamarca (11.95S; 76.87W) incoherent 
                         scatter radar during two events that occurred on 10 April 1997 and 
                         24 June 2008 and model calculation of the zonal drift in a 
                         realistic ionosphere simulated by the Sheffield University 
                         Plasmasphere-Ionosphere Model-INPE. Two main points are focused: 
                         (1) the connection between electric fields and plasma drifts under 
                         prompt penetration electric field during a disturbed periods and 
                         (2) anomalous behavior of daytime zonal drift in the absence of 
                         any magnetic storm. A perfect anticorrelation between vertical and 
                         zonal drifts was observed during the night and in the initial and 
                         growth phases of the magnetic storm. For the first time, based on 
                         a realistic low-latitude ionosphere, we will show, on a detailed 
                         quantitative basis, that this anticorrelation is driven mainly by 
                         a vertical Hall electric field induced by the primary zonal 
                         electric field in the presence of an enhanced nighttime E region 
                         ionization. It is shown that an increase in the field 
                         line-integrated Hall-to-Pedersen conductivity ratio 
                         \∑H\∑P, which can arise from precipitation of 
                         energetic particles in the region of the South American Magnetic 
                         Anomaly, is capable of explaining the observed anticorrelation 
                         between the vertical and zonal plasma drifts. Evidence for the 
                         particle ionization is provided from the occurrence of anomalous 
                         sporadic E layers over the low-latitude station, Cachoeira 
                         Paulista (22.67S; 44.9W)-Brazil. It will also be shown that the 
                         zonal plasma drift reversal to eastward in the afternoon two hours 
                         earlier than its reference quiet time pattern is possibly caused 
                         by weakening of the zonal wind system during the prolonged solar 
                         minimum period.",
                  doi = "10.1002/2015JA022146",
                  url = "http://dx.doi.org/10.1002/2015JA022146",
                 issn = "2169-9402",
             language = "en",
           targetfile = "santos_disturbance.pdf",
        urlaccessdate = "29 nov. 2020"