Results 41 to 50 of about 24,293 (260)

Tracking of polar cap ionospheric patches using data assimilation [PDF]

Journal of Geophysical Research: Space Physics, 2007
Ionospheric F‐region patches are 2–10 larger than background electron densities in the polar ionosphere. The EISCAT Svalbard incoherent radar (ESR) observed a sequence of patches between 2000–2200 UT on 12 December 2001. In this paper the source of these structures is investigated using several other data sets, together with a convection‐driven ...
G. S. Bust, G. Crowley
openaire   +1 more source

Multi-Instrument Observations of a Geomagnetic Storm and its Effects on the Arctic Ionosphere: A Case Study of the 19 February 2014 Storm:Observations of a Geomagnetic Storm [PDF]

, 2017
We present a multiinstrumented approach for the analysis of the Arctic ionosphere during the 19 February 2014 highly complex, multiphase geomagnetic storm, which had the largest impact on the disturbance storm-time index that year.
Alfonsi, Anderson, Anthony J. Mannucci, Attila Komjathy, Basu, Basu, Bhattacharyya, Blagoveshchenskii, Brekke, Buonsanto, Coker, Davies, Deng, Doherty, Durgonics, Emmert, Esayas B. Shume, Feldstein, Ghamry, Giraud, Gonzalez, Hans-Henrik Benzon, Hatch, Heelis, Hernandez-Pajares, Jacobsen, Jakowski, Kersley, Khazanov, Komjathy, Komjathy, Lastovicka, Le, Liemohn, Maini, Mannucci, Mannucci, Mark D. Butala, Matuura, Meier, Mendillo, Mendillo, Olga Verkhoglyadova, Paxton, Per Høeg, Pi, Prikryl, Prölls, Prölls, Richard B. Langley, Richmond, Rodger, Schunk, Sibson, Thomas, Tibor Durgonics, Tsurutani, Vennerstrøm, Vergados, Verkhoglyadova, Vickrey, Wei, Yau, Yau, Zhang   +64 more
core   +2 more sources

Localized structure in the cusp and high-latitude ionosphere: a modelling study [PDF]

Annales Geophysicae, 1999
The ionospheric signature of a flux transfer event (FTE) seen in EISCAT radar data has been used as the basis for a modelling study using a new numerical model of the high-latitude ionosphere developed at the University of Sheffield, UK. The evolution
H. F. Balmforth, R. J. Moffett, A. S. Rodger   +2 more
doaj   +1 more source

Positive storm effects in the dayside polar ionospheric F-region observed by EISCAT and ESR during the magnetic storm of 15 May 1997 [PDF]

Annales Geophysicae, 2002
EISCAT/ESR radar data and in situ FAST and POLAR satellite observations are coordinately analyzed to investigate positive ionospheric storm effects in the dayside upper F-region in both the polar cap and the auroral oval during the magnetic storm ...
S. Y. Ma, S. Y. Ma, H. T. Cai, H. X. Liu, K. Schlegel, G. Lu   +5 more
doaj   +1 more source

Statistical Characteristics of Polar Cap Patches Observed by RISR‐C [PDF]

Journal of Geophysical Research: Space Physics, 2018
AbstractPolar cap “patches” are ~100 to 1,000 km islands of high‐density plasma at polar latitudes, which can cause scintillation to communication and navigation signals. An automatic algorithm for patch identification has been developed and applied to the observations from the Resolute Bay Incoherent Scatter Radar‐Canada during January to March and ...
Jiaen Ren, Shasha Zou, Robert G. Gillies, Eric Donovan, Roger H. Varney   +4 more
openaire   +5 more sources

Multi-site observations of the association between aurora and plasma convection in the cusp/polar cap during a southeastward(B_y ~ |B_z|) IMF orientation [PDF]

Annales Geophysicae, 2003
In a case study we demonstrate the spatiotemporal structure of aurora and plasma convection in the cusp/polar cap when the interplanetary magnetic field (IMF) Bz < 0 and By ~ | Bz | (clock angle in GSM Y - Z plane: ~ 135°). This IMF orientation
P. E. Sandholt, J. Moen, C. J. Farrugia, S. W. H. Cowley, M. Lester, S. E. Milan, C. Valladares, W. F. Denig, S. Eriksson   +8 more
doaj   +1 more source

A broadband radio study of the average profile and giant pulses from PSR B1821-24A [PDF]

, 2015
We present the results of wide-band (720-2400 MHz) study of PSR B1821-24A (J1824-2452A, M28A), an energetic millisecond pulsar visible in radio, X-rays and gamma-rays. In radio, the pulsar has a complex average profile which spans >85% of the spin period
Bilous, A. V., Demorest, P., Pennucci, T. T., Ransom, S. M.   +3 more
core   +3 more sources

Two‐dimensional direct imaging of structuring of polar cap patches [PDF]

Journal of Geophysical Research: Space Physics, 2013
A highly sensitive all‐sky electron multiplier charge‐coupled device airglow imager has been operative in Longyearbyen, Norway (78.1°N, 15.5°E), since October 2011. The imager obtains the 630.0 nm all‐sky images with an exposure time of 4 s, which is about 10 times shorter than the conventional cooled CCD airglow imagers.
K. Hosokawa, S. Taguchi, Y. Ogawa, J. Sakai   +3 more
openaire   +1 more source

Observations of polar patches generated by solar wind Alfvén wave coupling to the dayside magnetosphere [PDF]

Annales Geophysicae, 1999
A long series of polar patches was observed by ionosondes and an all-sky imager during a disturbed period (Kp = 7- and IMF Bz < 0). The ionosondes measured electron densities of up to 9 × 1011 m-3 in the patch center, an increase above the density
P. Prikryl, J. W. MacDougall, I. F. Grant, I. F. Grant, D. P. Steele, G. J. Sofko, R. A. Greenwald   +6 more
doaj   +1 more source

Global imaging of polar cap patches with dual airglow imagers [PDF]

Geophysical Research Letters, 2014
During a 2 h interval from 2240 to 2440 UT on 12 November 2012, regions of increased 630.0 nm airglow emissions were simultaneously detected by dual all‐sky imagers in the polar cap, one at Longyearbyen, Norway (78.1°N, 15.5°E) and the other at Resolute Bay, Canada (74.7°N, 265.1°E). The Resolute Bay incoherent scatter radar observed clear enhancements
K. Hosokawa, S. Taguchi, K. Shiokawa, Y. Otsuka, Y. Ogawa, M. Nicolls   +5 more
openaire   +1 more source