@InProceedings{GoncharenkoZhLiTsBaRe:2017:LoDiLo,
author = "Goncharenko, Larisa P. and Zhang, Shunrong and Liu, Huixin and
Tsugawa, Takuya and Batista, Inez Staciarini and Reinisch, Bodo
W.",
affiliation = "{MIT Haystack Observatory} and {MIT Haystack Observatory} and
{Kyushu University} and NICT and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Lowell Digisonde International}",
title = "Longitudinal differences in the low-latitude ionosphere and in the
ionospheric variability",
booktitle = "Proceedings...",
year = "2017",
organization = "AGU Fall Meeting",
abstract = "Analysis of longitudinal differences in ionospheric parameters can
illuminate variety of mechanisms responsible for ionospheric
variability. In this study, we aim to 1) quantitatively describe
major features of longitudinal differences in peak electron
density in the low-latitude ionosphere; 2) examine differences in
ionospheric variability at different longitude sectors, and 3)
illustrate longitudinal differences in ionospheric response to a
large disturbance event, sudden stratospheric warming of 2016. We
examine NmF2 observations by a network of ionosondes in the
American (30-80W) and Asian (110-170E) longitudinal sectors.
Selected instruments are located in the vicinity of EIA troughs
(Jicamarca, Sao Luis, Guam, Kwajalein), northern and southern
crests of EIA (Boa Vista, Tucuman, Cachoeira Paulista, Okinawa),
and beyond EIA crests (Ramey, Yamagawa, Kokubunji). To examine
main ionospheric features at each location, we use long-term
datasets collected at each site to construct empirical models that
describe variations in NmF2 as a function of local time, season,
solar flux, and geomagnetic activity. This set of empirical models
can be used to accurately describe background ionospheric behavior
and serve as a set of observational benchmarks for global
circulation models. It reveals, for example, higher NmF2 in the
EIA trough in the Asian sector as compared to the American sector.
Further, we quantitatively describe variability in NmF2 as a
difference between local observations and local empirical model,
and find that American sectors EIA trough has overall higher
variability that maximizes for all local times during wintertime,
while Asian sector trough variability does not change
significantly with season. Additionally, local empirical models
are used to isolate ionospheric features resulting from dynamical
disturbances of different origin (e.g. geomagnetic storms,
convective activity, sudden stratospheric warming events, etc.).
We illustrate this approach with the case of sudden stratospheric
warming of 2016.",
conference-location = "New Orleans",
conference-year = "11-15 Dec.",
language = "en",
targetfile = "goncharenko_longitudinal.pdf",
urlaccessdate = "19 mar. 2024"
}