@Article{RodriguesHysePaul:2008:LaWaBo,
               author = "Rodrigues, F. S. and Hysell, D. L. and Paula, Eurico Rodrigues 
                         de",
          affiliation = "Cornell University, Earth and Atmospheric Sciences and Cornell 
                         University, Earth and Atmospheric Sciences and {Instituto Nacional 
                         de Pesquisas Espaciais (INPE)}",
                title = "Coherent backscatter radar imaging in Brazil: large-scale waves in 
                         the bottomside F-region at the onset of equatorial spread F",
              journal = "Annales Geophysicae",
                 year = "2008",
               volume = "26",
               number = "11",
                pages = "3355--3364",
             abstract = "The 30 MHz coherent backscatter radar located at the equatorial 
                         observatory in S{\~a}o Lu{\'{\i}}s, Brazil (2.59° S, 44.21° W, 
                         \−2.35° dip lat) has been upgraded to perform coherent 
                         backscatter radar imaging. The wide field-of-view of this radar 
                         makes it well suited for radar imaging studies of ionospheric 
                         irregularities. Radar imaging observations were made in support to 
                         the spread F Experiment (SpreadFEx) campaign. This paper describes 
                         the system and imaging technique and presents results from a 
                         bottom-type layer that preceded fully-developed radar plumes on 25 
                         October 2005. The radar imaging technique was able to resolve 
                         decakilometric structures within the bottom-type layer. These 
                         structures indicate the presence of large-scale waves (~35 km) in 
                         the bottomside F-region with phases that are alternately stable 
                         and unstable to wind-driven gradient drift instabilities. The 
                         observations suggest that these waves can also cause the initial 
                         perturbation necessary to initiate the Generalized Rayleigh-Taylor 
                         instability leading to spread F. The electrodynamic conditions and 
                         the scale length of the bottom-type layer structures suggest that 
                         the waves were generated by the collisional shear instability. 
                         These results indicate that monitoring bottom-type layers may 
                         provide helpful diagnostics for spread F forecasting.",
                 issn = "0992-7689",
             language = "en",
           targetfile = "coherent.pdf",
        urlaccessdate = "15 jun. 2024"
}