@Article{BatistaAbduMacDSouz:2002:LoTeTr,
               author = "Batista, Inez Staciarini and Abdu, Mangalathayil Ali and 
                         MacDougall, J. and Souza, Jonas Rodrigues de",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and University of Western 
                         Ontario, Canada and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)}",
                title = "Long term trends in the frequency of occurrence of the F3 layer 
                         over Fortaleza, Brazil",
              journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
                 year = "2002",
               volume = "64",
               number = "12-14",
                pages = "1409--1412",
                month = "Aug.-Sep.",
             keywords = "ionosfericas, atividade solar, regi{\~a}o F, camadas, 
                         ionospherics, solar ativity, F region, layers, magnetic equator.",
             abstract = "Recent studies using model calculation and ionospheric 
                         observations have revealed the existence of an additional layer in 
                         the topside equatorial ionosphere, the F3 layer. The observations 
                         using bottomside ionograms from locations close to the magnetic 
                         equator in Brazilian region have shown that the occurrence of the 
                         layer is very high from December to February (local summer)and 
                         from June to August (local winter). In fact, for the year 1995 the 
                         occurrence of the F3 layer is >75 percent during the months of 
                         January, February and December, and it is >65 percent for the 
                         period of June, July and August (Geofisica Int. 39 (2000)57). In 
                         this work, we use 25 years of data for the months of January and 
                         August to investigate how the layer occurrence varies with the 
                         magnetic dip angle and solar activity.",
                 issn = "1364-6826",
                label = "9881",
             language = "en",
           targetfile = "1-s2.0-S1364682602001049-main.pdf",
        urlaccessdate = "13 maio 2024"
}