@Article{HajraCTDEBGS:2016:EmMoIo,
author = "Hajra, Rakjumar and Chakraborty, Shyamal Kumar and Tsurutani,
Bruce T. and DasGupta, Ashish and Echer, Ezequiel and Brum,
Christiano G. M. and Gonzalez Alarcon, Walter Dem{\'e}trio and
Sobral, Jos{\'e} Humberto Andrade",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Raja Peary
Mohan College} and {Jet Propulsion Laboratory} and {University of
Calcutta} and {Instituto Nacional de Pesquisas Espaciais (INPE)}
and {Arecibo Observatory/SRI International} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)}",
title = "An empirical model of ionospheric total electron content (TEC)
near the crest of the equatorial ionization anomaly (EIA)",
journal = "Journal of Space Weather and Space Climate",
year = "2016",
volume = "6",
pages = "A29",
month = "July",
keywords = "Ionosphere (equatorial), Solar activity, Solar cycle, Total
electron content, Forecasting.",
abstract = "We present a geomagnetic quiet time (Dst > -50 nT) empirical model
of ionospheric total electron content (TEC) for the northern
equatorial ionization anomaly (EIA) crest over Calcutta, India.
The model is based on the 1980-1990 TEC measurements from the
geostationary Engineering Test Satellite-2 (ETS-2) at the
Haringhata (University of Calcutta, India: 22.58 degrees N, 88.38
degrees E geographic; 12.09 degrees N, 160.46 degrees E
geomagnetic) ionospheric field station using the technique of
Faraday rotation of plane polarized VHF (136.11 MHz) signals. The
ground station is situated virtually underneath the northern EIA
crest. The monthly mean TEC increases linearly with F-10.7 solar
ionizing flux, with a significantly high correlation coefficient
(r - 0.89-0.99) between the two. For the same solar flux level,
the TEC values are found to be significantly different between the
descending and ascending phases of the solar cycle. This
ionospheric hysteresis effect depends on the local time as well as
on the solar flux level. On an annual scale, TEC exhibits
semiannual variations with maximum TEC values occurring during the
two equinoxes and minimum at summer solstice. The semiannual
variation is strongest during local noon with a summer-to-equinox
variability of similar to 50-100 TEC units. The diurnal pattern of
TEC is characterized by a pre-sunrise (0400-0500 LT) minimum and
near-noon (1300-1400 LT) maximum. Equatorial electrodynamics is
dominated by the equatorial electrojet which in turn controls the
daytime TEC variation and its maximum. We combine these long-term
analyses to develop an empirical model of monthly mean TEC. The
model is validated using both ETS-2 measurements and recent GNSS
measurements. It is found that the present model efficiently
estimates the TEC values within a 1-sigma range from the observed
mean values.",
doi = "10.1051/swsc/2016023",
url = "http://dx.doi.org/10.1051/swsc/2016023",
issn = "2115-7251",
language = "en",
targetfile = "hajra_an empirical.pdf",
urlaccessdate = "28 abr. 2024"
}