Zobrazeno 1 - 10
of 50
pro vyhledávání: '"E. F. Donovan"'
Publikováno v:
Earth and Planetary Physics, Vol 8, Iss 1, Pp 258-274 (2024)
The recently deployed Transition Region Explorer (TREx)-RGB (red-green-blue) all-sky imager (ASI) is designed to capture “true color” images of the aurora and airglow. Because the 557.7 nm green line is usually the brightest emission line in visi
Externí odkaz:
https://doaj.org/article/f60e30aeba8a42b28a0cbdd4bb451956
Publikováno v:
Earth, Planets and Space, Vol 72, Iss 1, Pp 1-10 (2020)
Abstract We examined how much large-scale and localized upward and downward currents contribute to the substorm current wedge (SCW), and how they evolve over time, using the THEMIS all-sky imagers (ASIs) and ground magnetometers. One type of events i
Externí odkaz:
https://doaj.org/article/3e8b47c77ce5491d951e199886019d27
Autor:
B. J. Jackel, C. Unick, F. Creutzberg, G. Baker, E. Davis, E. F. Donovan, M. Connors, C. Wilson, J. Little, M. Greffen, N. McGuffin
Publikováno v:
Geoscientific Instrumentation, Methods and Data Systems, Vol 5, Iss 2, Pp 493-512 (2016)
Observations of astronomical sources provide information that can significantly enhance the utility of auroral data for scientific studies. This report presents results obtained by using Jupiter for field cross calibration of four multispectral auror
Externí odkaz:
https://doaj.org/article/3fbb812055254de1859d564d7ac483d5
Publikováno v:
Annales Geophysicae, Vol 30, Pp 467-488 (2012)
In this study we perform a statistical survey of the extremely-low-frequency wave activities associated with fast earthward flows in the mid-tail central plasma sheet (CPS) based upon THEMIS measurements. We reveal clear trends of increasing wave
Externí odkaz:
https://doaj.org/article/b670234eca4b46bb8d454332759d6c8b
Publikováno v:
Annales Geophysicae, Vol 27, Pp 2191-2204 (2009)
In this paper we present two substorm events with coordinated ground-based and in-situ THEMIS observations, and focus our interest on the wave activities in Pi1 and Pi2 bands from minutes before the substorm expansion phase (EP) onset to minutes a
Externí odkaz:
https://doaj.org/article/3a9f7d0071bb4ff3b92907f8a174b2ff
Publikováno v:
Annales Geophysicae, Vol 25, Pp 1199-1214 (2007)
We present simultaneous riometer observations of cosmic noise absorption in the nightside and dawn-noon sectors during sawtooth particle injections during 18 April 2002. Energetic electron precipitation (>30 keV) is a feature of magnetospheric sub
Externí odkaz:
https://doaj.org/article/e5ca1acc65804ab9a57b0da1c2780daf
Publikováno v:
Annales Geophysicae, Vol 23, Pp 3599-3613 (2005)
Multi-instrument observations of a small substorm event on 9 October 2000 provide, with high time resolution, two-dimensional information about substorm dynamics. A sequence of three optical intensifications, each associated with a Pi2 burst, were
Externí odkaz:
https://doaj.org/article/17f02293377747279ed6c2b3df23453b
Autor:
O. Amm, E. F. Donovan, H. Frey, M. Lester, R. Nakamura, J. A. Wild, A. Aikio, M. Dunlop, K. Kauristie, A. Marchaudon, I. W. McCrea, H.-J. Opgenoorth, A. Strømme
Publikováno v:
Annales Geophysicae, Vol 23, Pp 2129-2170 (2005)
A little more than four years after its launch, the first magnetospheric, multi-satellite mission Cluster has already tremendously contributed to our understanding about the coupled solar wind - magnetosphere - ionosphere system. This is mostly du
Externí odkaz:
https://doaj.org/article/b56a132ebcb4402096e02d861729c223
Autor:
M. T. Syrjäsuo, E. F. Donovan
Publikováno v:
Annales Geophysicae, Vol 22, Pp 1103-1113 (2004)
Modern ground-based digital auroral All-Sky Imager (ASI) networks capture millions of images annually. Machine vision techniques are widely utilised in the retrieval of images from large data bases. Clearly, they can play an important scientific r
Externí odkaz:
https://doaj.org/article/1ba191b6331045b88d8d47f451e8b04e
Autor:
P. T. Jayachandran, E. F. Donovan, J. W. MacDougall, D. R. Moorcroft, J.-P. St. Maurice, P. Prikryl
Publikováno v:
Annales Geophysicae, Vol 20, Pp 1899-1904 (2002)
We compare the locations of the equatorward boundaries of SuperDARN E-region backscatter and Hb emissions, focusing on the dusk-midnight sector of the auroral oval where the proton aurora is statistically located equatorward of the discrete el
Externí odkaz:
https://doaj.org/article/d1f5cf7391604a3da7ede83a5e25cedc