@Article{AbduMedeBittBati:1983:VeIoDr,
author = "Abdu, Mangalathyil Ali and Medeiros, Rui Tertuliano and
Bittencourt, Jos{\'e} Augusto and Batista, Inez Staciarini",
title = "Vertical ionization drift velocities and range type spread f in
the evening equatorial ionosphere",
journal = "Journal of Geophysical Research",
year = "1983",
volume = "88",
number = "A1",
pages = "399--402",
month = "Jan..",
keywords = "AERONOMIA, propaga{\c{c}}{\~a}o F, ionogramas, equador
magn{\'e}tico, spreed F, ionograms, magnetic equator.",
abstract = "Range type spread F indices in the post sunset hours, determined
from ionograms, are compared with F layer vertical velocities,
also deduced from ionograms, for a period of one year, over the
magnetic equatorial station Fortaleza (geographic coordinates: 4
degree S, 38 degree W; dip latitude: 1.8 degree S), Brazil.
Besides good correlation between the two parameters, the results
suggest the presence of a certain threshold value for the vertical
ionization velocity and a corresponding threshold height for the
base of the evening F layer,- as one of the necessary conditions
for the occurrence of spread F irregularities valid for southern
solstice (summer)and equinoctial months. The nature of the
possible variabilities in the amplitude of the initial
perturbation in the ionization (seeding mechanism), which is
another prerequisite for the generation of irregularities, is
discussed briefly.",
issn = "0148-0227 and 2156-2202",
label = "9453",
targetfile = "8429.pdf",
urlaccessdate = "28 abr. 2024"
}