@Article{CandidoSBBCAMBCWL:2019:CaSt,
               author = "Candido, Cl{\'a}udia Maria Nicoli and Shi, Jiankui and Batista, 
                         Inez Staciarini and Becker Guedes, F{\'a}bio and Correia, 
                         Em{\'{\i}}lia and Abdu, Mangalathayil Ali and Makela, Jonathan 
                         and Balan, Nanan and Chapagain, Narayan and Wang, Chi and Liu, 
                         Zhengkuan",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Chinese 
                         Academy of Sciences} 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 {University 
                         of Illinois at Urbana–Champaign} and {Chinese Academy of Sciences} 
                         and {Tribhuvan University} and {Chinese Academy of Sciences} and 
                         {Chinese Academy of Sciences}",
                title = "Postmidnight equatorial plasma irregularities on the June solstice 
                         during low solar activity - a case study",
              journal = "Annales Geophysicae",
                 year = "2019",
               volume = "37",
               number = "4",
                pages = "657--672",
                month = "July",
             abstract = "We present a case study of unusual spread-F structures observed by 
                         ionosondes at two equatorial and low-latitude Brazilian stations - 
                         Sao Luis (SL: 44.2 degrees W, 2.33 degrees S; dip angle: -6.9 
                         degrees) and Fortaleza (FZ: 38.45 degrees W, 3.9 degrees S; dip 
                         angle: -16 degrees). The irregularity structures observed from 
                         midnight to postmidnight hours of moderate solar activity (F10.7 < 
                         97 sfu, where 1 sfu = 10(-22) W m(-2) s(-1)) have characteristics 
                         different from typical post-sunset equatorial spread F. The 
                         spread-F traces first appeared at or above the F-layer peak and 
                         gradually became well-formed mixed spread F. They also appeared as 
                         plasma depletions in the 630.0 nm airglow emissions made by a 
                         wide-angle imager located at the nearby low-latitude station 
                         Cajazeiras (CZ: 38.56 degrees W, 6.87 degrees S; dip angle: -21.4 
                         degrees). The irregularities appeared first over FZ and later over 
                         SL, giving evidence of an unusual westward propagation or a 
                         horizontal plasma advection. The drift-mode operation available in 
                         one of the ionosondes (a digital portable sounder, DPS-4) has 
                         enabled us to analyze the horizontal drift velocities and 
                         directions of the irregularity movement. We also analyzed the 
                         neutral wind velocity measured by a Fabry-Perot interferometer 
                         (FPI) installed at CZ and discuss its possible role in the 
                         development of the irregularities.",
                  doi = "10.5194/angeo-37-657-2019",
                  url = "http://dx.doi.org/10.5194/angeo-37-657-2019",
                 issn = "0992-7689",
             language = "en",
           targetfile = "candido_postmi.pdf",
        urlaccessdate = "27 abr. 2024"
}