[2] The morphology of quiet time
F2 -layer disturbances
( Q disturbances) at middle latitudes along with general
discussion of the problem has been described by
Mikhailov et al. [2004]
(hereinafter referred to as MDL).
The revealed morphological picture turned out to be pretty
complicated indicating that various processes (depending
on geophysical conditions) contribute to those variations.
The formation mechanism of the equatorial
F2 layer is
different from the midlatitude one; therefore different
morphological pattern of quiet time disturbances is
expected. The
F2 layer at geomagnetic equator is mainly
controlled by vertical
EB
plasma drift due to zonal
electric field. The latter is known to be very variable
[Fejer et al., 1991;
Hari and Krishna Murthy, 1995;
Namboothiri et al., 1989;
Ramesh and Sastri, 1995;
Scherliess and Fejer, 1999;
Woodman, 1970],
even under quiet
conditions; therefore one may expect strong quiet time
perturbations in the equatorial
F2 region. Vertical plasma
drifts demonstrate longitudinal variations; therefore the
morphology will be considered for two equatorial stations,
Huancayo (American sector) and Kodaikanal (Indian
sector) separated practically by half a globe and located in
the southern and northern hemispheres, respectively. This
lucky situation allows one to analyze longitudinal and
hemispheric differences. This paper is devoted to a
morphological study of the equatorial
Q disturbances
along with a qualitative discussion of their possible
mechanisms.
Citation: 2005), Quiet time F2-layer disturbances at geomagnetic equator, Int. J. Geomagn. Aeron., 5, GI3001, doi:10.1029/2004GI000071.
Copyright 2005 by the American Geophysical Union (