Zobrazeno 1 - 10
of 29
pro vyhledávání: '"Th. Ulich"'
Publikováno v:
Annales Geophysicae, Vol 28, Pp 1409-1418 (2010)
The standard method of calculating the spectrum of a digital signal is based on the Fourier transform, which gives the amplitude and phase spectra at a set of equidistant frequencies from signal samples taken at equal intervals. In this paper a di
Externí odkaz:
https://doaj.org/article/9f206839dfc4403bacf99e5d64ddeeb1
Publikováno v:
Annales Geophysicae, Vol 25, Pp 407-415 (2007)
In this paper we study the effect of artificial HF heating on cosmic radio noise absorption in the D-region ionosphere. The effect has earlier been studied theoretically in idealised cases and without experimental verification. Here we present
Externí odkaz:
https://doaj.org/article/f1b3fd5750b4467198ab3c9b38d6d606
Publikováno v:
Annales Geophysicae, Vol 24, Pp 2025-2041 (2006)
High altitude nuclear explosions (HANEs) and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten
Externí odkaz:
https://doaj.org/article/412db7389c62429fb068c531d0099d67
Publikováno v:
Annales Geophysicae, Vol 24, Pp 187-202 (2006)
The solar proton event of October 1989 and especially the sunset of 23 October is examined in this study of negative ion chemistry, which combines measurements of nitric oxide, electron density, and cosmic radio noise absorption with ion and neutr
Externí odkaz:
https://doaj.org/article/e141a540ceb04f639e32abe60c935b87
Autor:
C.-F. Enell, A. Kero, E. Turunen, Th. Ulich, P. T. Verronen, A. Seppälä, S. Marple, F. Honary, A. Senior
Publikováno v:
Annales Geophysicae, Vol 23, Pp 1575-1583 (2005)
The upper mesosphere and lower thermosphere, or ionospheric D region, is an atmospheric layer which is difficult to access experimentally. A useful method that also has a large potential for further studies is artificial heating of electrons by
Externí odkaz:
https://doaj.org/article/4d96442833784a00887664d42dbe43fc
Publikováno v:
Annales Geophysicae, Vol 20, Pp 1967-1976 (2002)
Solar proton events and electron precipitation affect the concentrations of middle atmospheric constituents. Ionization caused by precipitating particles enhances the production of important minor neutral constituents, such as nitric oxide, t
Externí odkaz:
https://doaj.org/article/df1f68626be9422b89c01899dc669ff6
Publikováno v:
Annales Geophysicae, Vol 20, Pp 1137-1142 (2002)
Global geomagnetic activity has been suggested to be enhanced during weekends above the weekly average after 1930. Before the 1930s, weekends and weekdays were found to be equally active. This so-called "weekend effect" was suggested to be du
Externí odkaz:
https://doaj.org/article/d796e5b00ea4451385e45cb18486af0c
Publikováno v:
Annales Geophysicae, Vol 24, Iss 1, Pp 187-202 (2006)
Annales Geophysicae, Vol 24, Pp 187-202 (2006)
ResearcherID
Annales Geophysicae, Vol 24, Pp 187-202 (2006)
ResearcherID
The solar proton event of October 1989 and especially the sunset of 23October is examined in this study of negative ion chemistry, which combines measurements of nitric oxide, electron density, and cosmic radio noise absorption with ion and neutral c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5a023931b76cc78829b711c97fb12acd
https://www.ann-geophys.net/24/187/2006/
https://www.ann-geophys.net/24/187/2006/
Publikováno v:
Annales Geophysicae, Vol 20, Iss 8, Pp 1137-1142 (0000)
Annales Geophysicae, Vol 20, Pp 1137-1142 (2002)
ResearcherID
Annales Geophysicae, Vol 20, Pp 1137-1142 (2002)
ResearcherID
Global geomagnetic activity has been suggested to be enhanced during weekends above the weekly average after 1930. Before the 1930s, weekends and weekdays were found to be equally active. This so-called "weekend effect" was suggested to be due to pow
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fe8bfd3ba1eff3129c672826f86a93ec
https://www.ann-geophys.net/20/1137/2002/
https://www.ann-geophys.net/20/1137/2002/
Publikováno v:
Annales Geophysicae, Vol 20, Pp 1967-1976 (2002)
ResearcherID
Annales Geophysicae, Vol 20, Iss 12, Pp 1967-1976 (0000)
ResearcherID
Annales Geophysicae, Vol 20, Iss 12, Pp 1967-1976 (0000)
Solar proton events and electron precipitation affect the concentrations of middle atmospheric constituents. Ionization caused by precipitating particles enhances the production of important minor neutral constituents, such as nitric oxide, through r
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::09450355043d83002ff63c4ea32b5791
https://www.ann-geophys.net/20/1967/2002/
https://www.ann-geophys.net/20/1967/2002/