author = "Rodrigues, Fabiano da Silveira and Zhan, Weijia and Milla, Marco 
                         A. and Fejer, Bela G. and Paula, Eurico Rodrigues de and Cunha 
                         Neto, Ac{\'a}cio and Santos, Angela Machado dos and Batista, Inez 
          affiliation = "{The University of Texas at Dallas} and {The University of Texas 
                         at Dallas} and {Instituto Geofisicio del Peru} and {Utah State 
                         University} 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)}",
                title = "MELISSA: System description and spectral features of pre- and 
                         post-midnight F-region echoes",
              journal = "Journal of Geophysical Research: Space Physics",
                 year = "2019",
               volume = "2019",
             keywords = "equatorial, irregularities, ionosphere, radar, spread F.",
             abstract = "Most of the low-latitude ionospheric radar observations in South 
                         America come from the Jicamarca Radio Observatory, located in the 
                         western longitude sector (similar to 75 degrees W). The deployment 
                         of the 30 MHz FAPESP-Clemson-INPE (FCI) coherent backscatter radar 
                         in the magnetic equatorial site of Sao Luis, Brazil, in 2001 
                         allowed observations to be made in the eastern sector (similar to 
                         45 degrees W). However, despite being operational for several 
                         years (2001-2012), FCI only made observations during daytime and 
                         pre-midnight hours, with a few exceptions. Here, we describe an 
                         upgraded system that replaced the FCI radar and present results of 
                         full-night F-region observations. This radar is referred to as 
                         Measurements of Equatorial and Low-latitude Ionospheric 
                         irregularities over Sao Luis, South America (MELISSA), and made 
                         observations between March 2014 and December 2018. We present 
                         results of our analyses of pre- and post-midnight F-region echoes 
                         with focus on the spectral features of post-midnight echoes and 
                         how they compare to spectra of echoes observed in the post-sunset 
                         sector. The radar observations indicate that post-midnight 
                         F-region irregularities were generated locally and were not a 
                         result of {"}fossil{"} structures generated much earlier in time 
                         (in other longitude sectors) and that drifted into the radar 
                         field-of-view. This also includes cases where the echoes are weak 
                         and that would be associated with decaying equatorial spread F 
                         (ESF) structures. Collocated digisonde observations show modest 
                         but noticeable F-region apparent uplifts prior to post-midnight 
                         ESF events. We associate the equatorial uplifts with disturbed 
                         dynamo effects and with destabilizing F-region conditions leading 
                         to ESF development.",
                  doi = "10.1029/2019JA027445",
                  url = "http://dx.doi.org/10.1029/2019JA027445",
                 issn = "2169-9402",
             language = "en",
           targetfile = "rodrigues_melissa.pdf",
        urlaccessdate = "17 abr. 2021"