Zobrazeno 1 - 10
of 151
pro vyhledávání: '"T. K. Yeoman"'
Publikováno v:
Annales Geophysicae, Vol 38, Pp 575-590 (2020)
Polar holes were observed in the high-latitude ionosphere during a series of multi-instrument case studies close to the Northern Hemisphere winter solstice in 2014 and 2015. These holes were observed during geomagnetically quiet conditions and under
Externí odkaz:
https://doaj.org/article/c50b98a472da484ebdb888164689e705
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
Publikováno v:
Annales Geophysicae, Vol 28, Pp 1723-1735 (2010)
A combination of an HF Doppler sounder, a network of ground magnetometers, upstream solar wind monitors and a numerical model is used to examine the temporal evolution of an Ultra Low Frequency (ULF) wave. The event occurred on 16 April 1998 and f
Externí odkaz:
https://doaj.org/article/26ecd692c7d147dd8af6701012e5b93f
Publikováno v:
Annales Geophysicae, Vol 28, Pp 1499-1509 (2010)
A case study of SuperDARN observations of Pc5 Alfvén ULF wave activity generated in the immediate aftermath of a modest-intensity substorm expansion phase onset is presented. Observations from the Hankasalmi radar reveal that the wave had a perio
Externí odkaz:
https://doaj.org/article/bf8cc66b15a24b3d8176f85279cb5148
Publikováno v:
Annales Geophysicae, Vol 27, Pp 3591-3599 (2009)
Space Plasma Exploration by Active Radar (SPEAR) is a high-latitude ionospheric heating facility capable of exciting ULF waves on local magnetic field lines. We examine an interval from 1 February 2006 when SPEAR was transmitting a 1 Hz modulation
Externí odkaz:
https://doaj.org/article/285897e2374a480188ec47378beeb757
Autor:
L. B. N. Clausen, T. K. Yeoman
Publikováno v:
Annales Geophysicae, Vol 27, Pp 3237-3248 (2009)
In the first part of this study we present two case studies of pulsations that, with the help of ground-based data, are identified as field line resonances (FLRs). These pulsations occurred at frequencies which belong to a set of frequencies that
Externí odkaz:
https://doaj.org/article/61a31bbe0f95420fad294b6238b1bcb7
Autor:
D. M. Wright, R. S. Dhillon, T. K. Yeoman, T. R. Robinson, E. C. Thomas, L. J. Baddeley, S. Imber
Publikováno v:
Annales Geophysicae, Vol 27, Pp 2623-2631 (2009)
On 10 October 2006 the SPEAR high power radar facility was operated in a power-stepping mode where both CUTLASS radars were detecting backscatter from the SPEAR-induced field-aligned irregularities (FAIs). The effective radiated power of SPEAR was
Externí odkaz:
https://doaj.org/article/007cccec327e4db183b6a37064630ffa
Autor:
C. Forsyth, M. Lester, R. C. Fear, E. Lucek, I. Dandouras, A. N. Fazakerley, H. Singer, T. K. Yeoman
Publikováno v:
Annales Geophysicae, Vol 27, Pp 2457-2474 (2009)
Following a solar wind pressure pulse on 3 August 2001, GOES 8, GOES 10, Cluster and Polar observed dipolarizations of the magnetic field, accompanied by an eastward expansion of the aurora observed by IMAGE, indicating the occurrence of two subst
Externí odkaz:
https://doaj.org/article/18adf1ba4b604535ad4d39e9e1f570da
Publikováno v:
Annales Geophysicae, Vol 27, Pp 591-600 (2009)
Using data from the Super Dual Auroral Radar Network (SuperDARN) we investigate the ionospheric convection response to magnetospheric substorms. Substorms were identified using the Far Ultraviolet (FUV) instrument on board the Imager for Magnetopa
Externí odkaz:
https://doaj.org/article/0861b1b9fe6445e9a2ca9f5c00f140b2
Publikováno v:
Annales Geophysicae, Vol 27, Pp 65-81 (2009)
Previous studies of the aspect sensitivity of heater-enhanced incoherent radar backscatter in the high-latitude ionosphere have demonstrated the directional dependence of incoherent scatter signatures corresponding to artificially excited electros
Externí odkaz:
https://doaj.org/article/0392861dd81245f28e144900cb419d51