Results 111 to 120 of about 4,774 (237)

A localised co-rotating auroral absorption event observed near noon using imaging riometer and EISCAT [PDF]

, 1996
International audienceAn isolated region of energetic electron precipitation observed near local noon in the auroral zone has been investigated using imaging riometer (IRIS) and incoherent-scatter radar (EISCAT) techniques.
P. N. Collis, G. P. White, White, G. P., Collis, P. N., White, G.P., Hargreaves, J.K., Hargreaves, J. K., J. K. Hargreaves, Collis, P.N.   +8 more
core   +1 more source

How the Relative Contribution of DP‐1 and DP‐2 Currents Reshapes the Global Current System During Substorms

Geophysical Research Letters, Volume 53, Issue 11, 16 June 2026.
Abstract Geomagnetic disturbances in polar regions can be decomposed into two main patterns: the Disturbance Polar (DP) 1 and 2. How their relative contribution reshapes global current system remains unclear. In this study, we classified substorms from 2010 to 2022 into weak and strong DP‐2 events based on the ratio of the eastward to westward auroral ...
Jiarong Ma, Chao Yue, Haobo Fu, Shan Wang, Qiugang Zong, Xuzhi Zhou   +5 more
wiley   +1 more source

Simulation study of near-Earth space disturbances: 2. Auroral substorms

Progress in Earth and Planetary Science, 2019
A substorm is a transient phenomenon that lasts for only 1–2 h. One significant manifestation of the substorm is a sudden brightening of the aurora on the nightside.
Yusuke Ebihara
doaj   +1 more source

Vertical evolution of auroral acceleration at substorm onset [PDF]

, 2009
This study describes the onset process of auroral substorms in connection with the vertical evolution of auroral particle acceleration, on the basis of auroral kilometric radiation (AKR) dynamics.
Morioka, A., A. Morioka, R. R. Anderson, Misawa, H., Anderson, R.R., J. D. Menietti, Honary, F., F. Tsuchiya, Tsuchiya, F., Miyoshi, Y., Parks, G.K., Menietti, J.D., H. Misawa, G. K. Parks, Y. Miyoshi, Yumoto, K., F. Honary, K. Yumoto   +17 more
core   +1 more source

Temperature enhancements and vertical winds in the lower thermosphere associated with auroral heating during the DELTA campaign [PDF]

, 2009
A coordinated observation of the atmospheric response to auroral energy input in the polar lower thermosphere was conducted during the Dynamics and Energetics of the Lower Thermosphere in Aurora (DELTA) campaign.
Kurihara, J., Abe, T., Y. Ogawa, Oyama, K.-I., S. Oyama, S. Nozawa, T. T. Tsuda, T. Abe, Nozawa, S., Griffin, E., N. Iwagami, H. Miyaoka, E. Griffin, R. Fujii, Tsuda, T. T., K.-I. Oyama, Kauristie, K., Kosch, Mike J., Aruliah, A., Iwagami, N., J. Kurihara, A. Aruliah, Oyama, S., Miyaoka, H., Ogawa, Y., Fujii, R., M. J. Kosch, K. Kauristie   +27 more
core   +1 more source

Mesoscale observations of Joule heating near an auroral arc and ion-neutral collision frequency in the polar cap E region [PDF]

, 2011
We report on the first mesoscale combined ionospheric and thermospheric observations, partly in the vicinity of an auroral arc, from Svalbard in the polar cap on 2 February 2010. The EISCAT Svalbard radar employed a novel scanning mode in order to obtain
Wild, J.A., Yiu, I., Kosch, M.J., Anderson, C., I. Yiu, Y. Ogawa, Aruliah, A., Tsuda, T., I. W. McCrea, L. J. Baddeley, S. Nozawa, Howells, V., A. Aruliah, J. A. Wild, McCrea, I.W., V. Howells, Ogawa, Y., Nozawa, S., M. J. Kosch, C. Anderson, Baddeley, L.J., T. Tsuda   +21 more
core   +1 more source

Effects of D-region RF heating studied with the Sodankyla ion chemistry model [PDF]

, 2005
International audienceThe upper mesosphere and lower thermosphere, or ionospheric D region, is an atmospheric layer which is difficult to access experimentally.
A. Seppälä, A. Senior, Turunen, T., Ulich, T., Seppälä, A., C.-F. Enell, Enell, C.-F., Honary, F., P. T. Verronen, Marple, S., S. Marple, A. Kero, E. Turunen, Senior, A., Ulich, Th., Turunen, E., Th. Ulich, F. Honary, Verronen, P. T., Kero, A.   +19 more
core   +1 more source

Excitation of twin-vortex flow in the nightside high-latitude ionosphere during an isolated substorm [PDF]

, 2002
We present SuperDARN radar observations of the ionospheric flow during a well-observed high-latitude substorm which occurred during steady northward IMF conditions on 2 December 1999.
Tim K. Yeoman (7583066), S. W. H. Cowley, J. B. Sigwarth, Watermann, J.F., Sigwarth, J.B., Cowley, S.W.H., Grocott, A., S.W.H. Cowley (7591226), Adrian Grocott (7590026), Watermann, J. F., T. K. Yeoman, Cowley, S. W. H., J. F. Watermann, A. Grocott, Sigwarth, J. B., Yeoman, T. K., Yeoman, T.K., J.B. Sigwarth (7591229), J.F. Watermann (7591232)   +18 more
core   +1 more source

Dependence of the open-closed field line boundary in Saturn's ionosphere on both the IMF and solar wind dynamic pressure : comparison with the UV auroral oval observed by the HST [PDF]

, 2008
We model the open magnetic field region in Saturn's southern polar ionosphere during two compression regions observed by the Cassini spacecraft upstream of Saturn in January 2004, and compare these with the auroral ovals observed simultaneously in ...
Badman, S. V., Kalegaev, V.v., V. V. Kalegaev (7590551), Cowley, S. W. H., S. W. H. Cowley (7590302), Belenkaya, E. S., M. S. Blokhina (7614182), E. S. Belenkaya (7590545), S. V. Badman (7590704), Blokhina, M. S.   +9 more
core  

Synthesizing auroral substorm processes based on magnetosphere-ionosphere electric currents

Frontiers in Astronomy and Space Sciences
A synthesis of various processes associated with auroral substorms is attempted by considering medium intensity substorms. In this paper, we consider that the magnetosphere-ionosphere system is an electric current system.
Syun-Ichi Akasofu, A. T. Y. Lui, Lou-Chuang Lee   +2 more
doaj   +1 more source