Zobrazeno 1 - 10
of 420
pro vyhledávání: '"M. A. Abdu"'
Autor:
A. M. Santos, G. Yang, A. A. Pimenta, C. G. M. Brum, I. S. Batista, J. H. A. Sobral, V. F. Andrioli, P. P. Batista, M. A. Abdu, J. R. Souza, P. K. Manoharan, C. Wang, H. Li, Z. Liu
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 11 (2024)
This work presents the contribution of solar atmospheric tides (diurnal, semidiurnal, and terdiurnal modes) to the variability of the parameters critical frequency (foF2) and peak height of the F2-layer (hmF2) in the American sector during the transi
Externí odkaz:
https://doaj.org/article/143648537da249ea93bef0491ebdc1ef
Publikováno v:
Earth and Space Science, Vol 10, Iss 11, Pp n/a-n/a (2023)
Abstract The 14‐panel Advanced Modular Incoherent Scatter Radar (AMISR‐14) system deployed at Jicamarca observed equatorial spread F plumes on two consecutive nights under unfavorable seasonal and solar flux conditions during a period that can be
Externí odkaz:
https://doaj.org/article/da156924d50c4f4bad4a6e12cd2170e4
Publikováno v:
Annales Geophysicae, Vol 40, Pp 259-269 (2022)
This work presents the daytime behavior of the intermediate layer (ILs) parameters (the virtual height – h'IL, and the top frequency – ftIL) over the low-latitude region of Cachoeria Paulista (CP, 22.42∘ S; 45∘ W, I: −34.59∘) during the 2
Externí odkaz:
https://doaj.org/article/f1efff73a7684e198428166871050279
Autor:
H. Takahashi, P. Essien, C. A. O. B. Figueiredo, C. M. Wrasse, D. Barros, M. A. Abdu, Y. Otsuka, K. Shiokawa, GuoZhu Li
Publikováno v:
Earth and Planetary Physics, Vol 5, Iss 5, Pp 368-377 (2021)
Large Scale Wave Structures (LSWS) in the equatorial ionospheric F-region were observed by measuring spatial and temporal variations within detrended total electron content (dTEC) data obtained by ground-based GNSS receivers over the South American c
Externí odkaz:
https://doaj.org/article/bdd709c0f3d5421195c82edc0f7110d8
Publikováno v:
Annales Geophysicae, Vol 37, Pp 1005-1024 (2019)
In this work, we have performed a study for the first time on the climatology of the intermediate descending layers (ILs) over Brazilian equatorial and low-latitude regions during the extreme solar minimum period of 2009. The result of this study sho
Externí odkaz:
https://doaj.org/article/4610e81a4765416ba3e5b9f4724dc16d
Autor:
C. M. N. Candido, J. Shi, I. S. Batista, F. Becker-Guedes, E. Correia, M. A. Abdu, J. Makela, N. Balan, N. Chapagain, C. Wang, Z. Liu
Publikováno v:
Annales Geophysicae, Vol 37, Pp 657-672 (2019)
We present a case study of unusual spread-F structures observed by ionosondes at two equatorial and low-latitude Brazilian stations – São Luís (SL: 44.2∘ W, 2.33∘ S; dip angle: −6.9∘) and Fortaleza (FZ: 38.45∘ W, 3.9∘ S; dip a
Externí odkaz:
https://doaj.org/article/7c00fdb2be144cc6aabca9d5f604efde
Publikováno v:
Annales Geophysicae, Vol 36, Pp 609-620 (2018)
Equatorial plasma bubble/spread F irregularity occurrence can present large variability depending upon the intensity of the evening prereversal enhancement in the zonal electric field (PRE), that is, the F region vertical plasma drift, which basic
Externí odkaz:
https://doaj.org/article/d304c676822c4e63aadd63c6e3007276
Autor:
Guozhu Li, Baiqi Ning, M. A. Abdu, Chi Wang, Yuichi Otsuka, Weixing Wan, Jiuhou Lei, Michi Nishioka, Takuya Tsugawa, Lianhuan Hu, Guotao Yang, Chunxiao Yan
Publikováno v:
Progress in Earth and Planetary Science, Vol 5, Iss 1, Pp 1-9 (2018)
Abstract Unexpected daytime F-region irregularities following the appearance of an ionospheric hole have been observed over low latitude. The irregularities developed initially above the F-region peak height (~ 360 km) with a thickness of about 30 km
Externí odkaz:
https://doaj.org/article/cc617f1b55ea4b228af097462788f1d1
Autor:
P. A. B. Nogueira, M. A. Abdu, J. R. Souza, C. M. Denardini, P. F. Barbosa Neto, J. P. Serra de Souza da Costa, A. P. M. Silva
Publikováno v:
Annales Geophysicae, Vol 36, Pp 139-147 (2018)
We have analyzed low-latitude ionospheric current responses to two intense (X-class) solar flares that occurred on 13 May 2013 and 11 March 2015. Sudden intensifications, in response to solar flare radiation impulses, in the Sq and equatorial elec
Externí odkaz:
https://doaj.org/article/d1bcc831e7814e6a815b11ea4a2cc0f2
Publikováno v:
Annales Geophysicae, Vol 35, Pp 1219-1229 (2017)
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
Externí odkaz:
https://doaj.org/article/83fb738c4eb6444a91e245aaf3628b2e