author = "Paula, Eurico Rodrigues de and Oliveira, Cesar B. A. de and Caton, 
                         Ronald G. and Negreti, Patr{\'{\i}}cia Mara de Siqueira and 
                         Batista, Inez Staciarini and Martinon, Andr{\'e} Ricardo Fazanaro 
                         and Cunha Neto, Ac{\'a}cio and Abdu, Mangalathayil Ali and 
                         Monico, Jo{\~a}o F. G. and Jonas, Sousasantos and Moraes, Alison 
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {Air Force 
                         Research Laboratory} 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 (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Estadual 
                         Paulista (UNESP)} and {Instituto Tecnol{\'o}gico de 
                         Aeron{\'a}utica (ITA)} and {Instituto de Aeron{\'a}utica e 
                         Espa{\c{c}}o (IAE)}",
                title = "Ionospheric irregularity behavior during the September 6-10, 2017 
                         magnetic storm over Brazilian equatorial-low latitudes",
              journal = "Earth Planets and Space",
                 year = "2019",
               volume = "71",
                pages = "42",
                month = "Apr.",
             keywords = "Ionospheric irregularity, Ionospheric scintillation, Magnetic 
                         storm, Magnetospheric electric field penetration, 
                         Counter-electrojet, Plasma irregularity zonal velocity.",
             abstract = "The September 6-10, 2017 two-step magnetic storm was caused by an 
                         X9 solar flare followed by a CME. The SSC that occurred at 23:43 
                         UT on day 06 when Sym-H reached about 50 nT, was due to a sudden 
                         increase in solar wind. The first step of the storm was caused by 
                         a B-z southward incursion on day 07. The magnetic index K-p 
                         reached 08, and the Sym-H magnetic index reached a minimum value 
                         of -146 nT on day 08 at 01:08 UT, ending the main phase. On day 
                         07, the solar wind intensified once again and the auroral index AE 
                         reached 2500 nT. During the recovery phase of this first storm, 
                         there was another B-z southward incursion on day 08 at 13:56 UT 
                         when Sym-H reached -115 nT, and K-p reached a value of 08.33, 
                         marking the second step of the storm. In this work, the 
                         ionospheric irregularity over SAo Luis (02.5 degrees S, 44.3 
                         degrees W, dip lat -04.67 degrees) was studied using data from the 
                         VHF, Digisonde and GPS receivers. Electron density data from the 
                         satellite SWARM-A were also analyzed for those orbits close to SAo 
                         Luis, and they presented large fluctuations during the storm night 
                         of 07/08. To analyze the latitudinal effects of the storm on the 
                         plasma irregularities, GPS data from 6 Novatel receivers were 
                         used. The vertical plasma drifts during daytime hours were 
                         determined using magnetometer data and during the evening using 
                         ionogram data. Compared to the 'quiet' days of September 2017, the 
                         VHF and GPS S4 amplitude scintillation indices increased 
                         substantially during the night of 07/08 when there was a strong 
                         intensification in the vertical plasma drift due to a prompt 
                         penetration under shielding magnetospheric electric field of 
                         eastward polarity. On the other hand, on the night of 08/09 the 
                         ionospheric scintillation was completely inhibited due to the 
                         disturbance dynamo electric field of westward polarity associated 
                         with the first and second storms. The irregularity zonal drifts 
                         measured by a VHF receiver around 24 UT (21 LT) were eastward on 
                         the nights of 05/06 and 06/07; however, during the night of 07/08, 
                         it reversed to westward.",
                  doi = "10.1186/s40623-019-1020-z",
                  url = "http://dx.doi.org/10.1186/s40623-019-1020-z",
                 issn = "1880-5981",
             language = "en",
           targetfile = "paula_ionospheric.pdf",
        urlaccessdate = "17 abr. 2021"