Zobrazeno 1 - 10
of 220
pro vyhledávání: '"J. M. Ruohoniemi"'
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 11 (2024)
The phenomenon known as strong thermal emission velocity enhancement (STEVE) is a narrow optical structure that may extend longitudinally for thousands of kilometers. Initially observed by amateur photographers, it has recently garnered researchers
Externí odkaz:
https://doaj.org/article/8122643a6cd24f6189dc84c8fd787bc6
Autor:
D. D. Billett, K. A. McWilliams, R. B. Kerr, J. J. Makela, A. T. Chartier, J. M. Ruohoniemi, S. Kapali, M. A. Migliozzi, J. Riccobono
Publikováno v:
Annales Geophysicae, Vol 40, Pp 571-583 (2022)
We investigate the response of the mid-latitude thermospheric neutral winds to a sub-auroral polarization stream (SAPS) event. Using red line (F region) airglow data from two Fabry–Pérot interferometers (FPIs), and F-region ionospheric flow veloci
Externí odkaz:
https://doaj.org/article/a5930d0ec91e43488663f207636172a7
Autor:
Y. Zou, B. M. Walsh, Y. Nishimura, V. Angelopoulos, J. M. Ruohoniemi, K. A. McWilliams, N. Nishitani
Publikováno v:
Annales Geophysicae, Vol 37, Pp 215-234 (2019)
Magnetic reconnection can vary considerably in spatial extent. At the Earth's magnetopause, the extent generally corresponds to the extent in local time. The extent has been probed by multiple spacecraft crossing the magnetopause, but the estimates h
Externí odkaz:
https://doaj.org/article/498cff0822d7439394db200aff28eadf
Autor:
J. J. Zhang, W. Wang, C. Wang, A. L. Lan, J. Y. Yan, D. Xiang, Q. H. Zhang, J. M. Ruohoniemi, B. S. R. Kunduri, N. Nishitani, X. Shi, H. B. Qiu
Publikováno v:
Earth and Space Science, Vol 7, Iss 1, Pp n/a-n/a (2020)
Abstract The Super Dual Auroral Radar Network (SuperDARN) is an international low‐power high‐frequency (HF) radar network, which provides continuous observations of the motion of plasma in the ionosphere. Over the past 15 years, the network has e
Externí odkaz:
https://doaj.org/article/16dd8f017f2e4156bb7fa52840fa7665
Autor:
H. Y. Fu, W. A. Scales, P. A. Bernhardt, S. J. Briczinski, M. J. Kosch, A. Senior, M. T. Rietveld, T. K. Yeoman, J. M. Ruohoniemi
Publikováno v:
Annales Geophysicae, Vol 33, Pp 983-990 (2015)
Observations of secondary radiation, stimulated electromagnetic emission (SEE), produced during ionospheric modification experiments using ground-based, high-power, high-frequency (HF) radio waves are considered. The High Frequency Active Auroral
Externí odkaz:
https://doaj.org/article/03925c4b7737457ba8f7716ca3a248bc
Autor:
P. Prikryl, R. Ghoddousi-Fard, L. Spogli, C. N. Mitchell, G. Li, B. Ning, P. J. Cilliers, V. Sreeja, M. Aquino, M. Terkildsen, P. T. Jayachandran, Y. Jiao, Y. T. Morton, J. M. Ruohoniemi, E. G. Thomas, Y. Zhang, A. T. Weatherwax, L. Alfonsi, G. De Franceschi, V. Romano
Publikováno v:
Annales Geophysicae, Vol 33, Pp 657-670 (2015)
During the ascending phase of solar cycle 24, a series of interplanetary coronal mass ejections (ICMEs) in the period 7–17 March 2012 caused geomagnetic storms that strongly affected high-latitude ionosphere in the Northern and Southern Hemisphe
Externí odkaz:
https://doaj.org/article/aa47805529644e56bd3e17eeb28f6244
Autor:
P. Prikryl, R. Ghoddousi-Fard, E. G. Thomas, J. M. Ruohoniemi, S. G. Shepherd, P. T. Jayachandran, D. W. Danskin, E. Spanswick, Y. Zhang, Y. Jiao, Y. T. Morton
Publikováno v:
Annales Geophysicae, Vol 33, Pp 637-656 (2015)
The interval of geomagnetic storms of 7–17 March 2012 was selected at the Climate and Weather of the Sun-Earth System (CAWSES) II Workshop for group study of space weather effects during the ascending phase of solar cycle 24 (Tsurutani et al., 2
Externí odkaz:
https://doaj.org/article/9fd1534d40774de5ac2d670d06e53f42
Publikováno v:
Annales Geophysicae, Vol 29, Pp 1985-1996 (2011)
Meteor wind data from the first year of operation of the Falkland Islands SuperDARN radar (52° S, 59° W) are used to characterize the atmospheric tides and background winds in the upper mesosphere above the South Atlantic. Strong (>40 m s−1) s
Externí odkaz:
https://doaj.org/article/d0a494d6d99d43e384b5e6240bc3c56c
Autor:
H. Korth, B. J. Anderson, J. M. Ruohoniemi, H. U. Frey, C. L. Waters, T. J. Immel, D. L. Green
Publikováno v:
Annales Geophysicae, Vol 26, Pp 1415-1430 (2008)
The response of the polar ionosphere–thermosphere (I-T) system to electromagnetic (EM) energy input is fundamentally different to that from particle precipitation. To understand the I-T response to polar energy input one must know the intensitie
Externí odkaz:
https://doaj.org/article/08e60958047e49009a2e1fcc94ef15af
Autor:
S. B. Malinga, J. M. Ruohoniemi
Publikováno v:
Annales Geophysicae, Vol 25, Pp 1767-1778 (2007)
Data from the Super Dual Radar Network (SuperDARN) radars for 2002 were used to study the behaviour of the quasi-two-day wave (QTDW) in the Northern Hemisphere auroral zone. The period of the QTDW is observed to vary in the range of ~42–56 h, wi
Externí odkaz:
https://doaj.org/article/162916a038fc4ea09f7438e2183e3bfe