author = "Abdu, Mangalathayil Ali and Mediros, Rui Tertuliano and Sobral, 
                         Jos{\'e} Humberto Andrade and Bittencourt, Jos{\'e} Augusto",
                title = "Spread F plasma bubble vertical rise velocities determined from 
                         spaced ionosonde observations",
              journal = "Journal of Geophysical Research",
                 year = "1983",
               volume = "88",
               number = "A11",
                pages = "000",
                month = "Nov.",
             keywords = "AERONOMIA, ionosonda, sondas ionosf{\'e}ricas, bolhas de plasma, 
                         propaga{\c{c}}{\~a}o F, densidade dp plasma, ionosonds, plasma 
                         bubbles, spread F, plasma density.",
             abstract = "Systematic time differences in the onsets of spread F events in 
                         the ionograms are observed between the magnetic equatorial station 
                         Fortaleza (4 degree S, 38 degree W, dip latitude 1.8 degree S)and 
                         the low-latitude station Cachoeira Paulista (23 degree S, 45 
                         degree W, dip latitude 14 degree S), two stations in Brazil, 
                         located at close-by magnetic meridional planes (actually some 12 
                         degree of magnetic longitude apart). On the assumption, justified 
                         from different experimental observations, that the spread F 
                         irregularities occur in strongly field-aligned plasma bubbles that 
                         extend several degrees on either side of the magnetic equator, and 
                         rise up in vertically elongated columns over the magnetic equator, 
                         we have related the observed time differences in the onsets of 
                         spread F events at the two stations to the plasma bubble vertical 
                         rise velocities over the magnetic equator. The vertical rise 
                         velocities of the plasma bubble so determined are found to be well 
                         within the values measured by VHF radar and satellite techniques, 
                         and further show, at times, good correlations with the amplitude 
                         of the prereversal peak in the vertical drift velocities and the 
                         heights of the evening equatorial F layer. Possible implications 
                         of these results are discussed.",
                 issn = "0148-0227 and 2156-2202",
                label = "2258",
           targetfile = "INPE-2416.pdf",
        urlaccessdate = "24 jan. 2021"