@Article{SantosAbdSouBatSob:2017:UnBeQu,
author = "Santos, {\^A}ngela Machado dos and Abdu, Mangalathayil Ali and
Souza, Jonas Rodrigues de and Batista, Inez Staciarini and Sobral,
Jos{\'e} Humberto Andrade",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)}",
title = "Unusual behavior of quiet-time zonal and vertical plasma drift
velocities over Jicamarca during the recent extended solar minimum
of 2008",
journal = "Annales Geophysicae",
year = "2017",
volume = "35",
pages = "1219--1229",
keywords = "Ionosphere (equatorial ionosphere).",
abstract = "The influence of the recent deep and prolonged solar minimum on
the daytime zonal and vertical plasma drift velocities during
quiet time is investigated in this work. Analyzing the data
obtained from incoherent scatter radar from Jicamarca
(11.95\◦ S, 76.87\◦ W) we observe an anomalous
behavior of the zonal plasma drift during June 2008 characterized
by lower than usual daytime westward drift and its early afternoon
reversal to eastward. As a case study the zonal drift observed on
24 June 2008 is modeled using a realistic low-latitude ionosphere
simulated by the Sheffield University Plasmasphere-Ionosphere
Model-INPE (SUPIMINPE). The results show that an anomalously low
zonal wind was mainly responsible for the observed anomalous
behavior in the zonal drift. A comparative study of the vertical
plasma drifts obtained from magnetometer data for some periods of
maximum (20002002) and minimum solar activity (1998, 2008, 2010)
phases reveal a considerable decrease on the E-region conductivity
and the dynamo electric field during 2008. However, we believe
that the contribution of these characteristics to the unusual
behavior of the zonal plasma drift is significantly smaller than
that arising from the anomalously low zonal wind. The SUPIM-INPE
result of the critical frequency of the F layer (foF2) over
Jicamarca suggested a lower radiation flux than that predicted by
solar irradiance model (SOLAR2000) for June 2008.",
doi = "10.5194/angeo-35-1219-2017",
url = "http://dx.doi.org/10.5194/angeo-35-1219-2017",
issn = "0992-7689",
language = "en",
targetfile = "santos_unusual.pdf",
urlaccessdate = "05 maio 2024"
}