@Article{LiNiLiAbWaHu:2015:ShZoDr,
author = "Li, G. and Ning, B. and Liu, L. and Abdu, Mangalathayil Ali and
Wan, W. and Hu, L.",
affiliation = "{Chinese Academy of Sciences} and {Chinese Academy of Sciences}
and {Chinese Academy of Sciences} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {} and {Chinese Academy of
Sciences}",
title = "Shear in the zonal drifts of 3m irregularities inside spread F
plumes observed over Sanya",
journal = "Journal of Geophysical Research: Space Physics",
year = "2015",
volume = "120",
number = "9",
pages = "8146--8154",
month = "Sept.",
keywords = "A vertical shear in zonal drifts of ESF 3 m irregularities is
detected at low latitude, Better knowledge of plasma zonal drift
shear at low latitude are needed, The shear centers at an apex
altitude of 650 km over dip equator.",
abstract = "Incoherent scatter radars near magnetic equator regularly measured
a vertical shear in zonal drifts of the evening background plasma,
with westward drifts below the equatorial F region peak and
eastward drifts above. We report here observations of a clear
shear structure in the zonal drifts of 3m irregularities inside
spread F (SF) backscatter plumes measured with a 47.5MHz coherent
scatter radar operated at a low-latitude site Sanya (18.4N,
109.6E; dip latitude 12.8N). The radar interferometry analysis on
the zonal drifts of the 3m irregularities yields results
consistent with that estimated from the irregularity echo Doppler
velocity measurements with multiple beams. It is shown that the SF
3m irregularities move westward at the lowest altitudes, while at
higher altitudes in the same SF plume structure, the 3m
irregularities drift eastward. One interesting point is that the
vertical shear of zonal drifts was centered at ~300km altitude
over Sanya, which maps to an apex altitude of ~650km at magnetic
equator and is thus apparently higher than the apex altitudes
250-450km where the zonal velocity shear has usually been
observed. Analysis of the observations suggests that while the
possibility of local generation of the shear flow of the
irregularities can exist, the possibility of a plasma vortex
appearing at relative high altitudes causing the zonal drift shear
of F region 3m irregularities measured over Sanya cannot be
totally ruled out.",
doi = "10.1002/2015JA021497",
url = "http://dx.doi.org/10.1002/2015JA021497",
issn = "2169-9402",
language = "en",
urlaccessdate = "27 abr. 2024"
}