On the disappearance of the imf sector structure effect in the lower atmosphere in 1974–1977

1981 ◽  
Vol 25 (2) ◽  
pp. 208-210 ◽  
Author(s):  
Jan Laštovička ◽  
L. Křivský
1989 ◽  
Vol 33 (2) ◽  
pp. 198-205 ◽  
Author(s):  
Jürgen Bremer ◽  
Jan Laštovička ◽  
L. Křivský

1994 ◽  
Vol 37 (2) ◽  
Author(s):  
Y. Tulunay

Using criticaI frequencies, f0F2 from the Uppsala, Lannion and Dourbes ionosonde stations, the possible effects of the orientation of the IMF on mid-latitude ionosphere are further investigated. For this purpose, the regular diurnal, seasonal and solar cycle variations in the f0F2 data were removed by subtracting the mean of f0F2 for the same UT on all the magnetically quiet days (Ap< 6) within 15 days around the IMF Bz turnings. This yields the deviation from the average quiet-time value ?f0F2. The data are sorted according to the polarity of the IMF Bz and the effects of the southward turnings are discussed. Hapgood et al. (1991), Tulunay et al. (1991), Tulunay and Rahman (1992) investigated the possible effects of the IMF on mid-latitude ionosphere by employing the Slough and Argentine Islands f0F2 data. In order to facilitate a comparison the same method of analysis is being adopted again. However, in the present work the southward polarity changes in IMF Bz with no consideration of the IMF sector structure were considered only.


2021 ◽  
Vol 39 (2) ◽  
pp. 369-377
Author(s):  
Peter Stauning

Abstract. The only published description of the solar wind sector (SS) term used for the reference level in the post-event and real-time derivation of the Polar Cap (PC) indices, PCN (Polar Cap North) and PCS (Polar Cap South), in the version endorsed by the International Association for Geomagnetism and Aeronomy (IAGA) is found in the commented publication, Janzhura and Troshichev: Identification of the IMF sector structure in near-real time by ground magnetic data, Annales Geophysicae, 29, 1491–1500, 2011. Actually, the publication has served as a basis for the index endorsement by IAGA in 2013. However, neither the illustrations nor the results presented there have been derived by the specified near real-time method. Figures 1, 6, 7, and 8 display values derived by post-event calculations based on daily medians smoothed over 7 d centred on the day of interest. Figures 2, 3, and 4 display observed values smoothed over 7 d, while the remaining Fig. 5 displays averages over 4 months. In summary, there are strong disagreements between indications in the title, abstract, and statements in the text compared to the actual results and their illustrations.


1986 ◽  
Vol 30 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Jan Laštovička ◽  
F. Pechala
Keyword(s):  

2013 ◽  
Vol 31 (7) ◽  
pp. 1221-1225 ◽  
Author(s):  
P. Stauning

Abstract. The description presented in the paper of the relations of the solar wind sector structure to the derivation of the quiet daily variation (QDC) in polar magnetic recordings used for calculation of polar cap (PC) indices is found to be unclear and not properly justified. The presented example on inclusion of a solar sector term in an actual QDC series is found to be questionable even on the authors' premises.


2017 ◽  
Vol 13 (S335) ◽  
pp. 208-210
Author(s):  
Mikhail V. Vokhmyanin ◽  
Nadezhda V. Zolotova ◽  
Dmitry I. Ponyavin

AbstractThe interplanetary magnetic field (IMF) controls magnetospheric currents which cause variations of the ground-based magnetic field. Regular magnetic observations made in the 19th century allow us to infer daily IMF polarities back to 1844. The results coincide with satellite data in about 79% days. Moreover, for the most part of the 19th and 20th centuries, proxies obtained from various geomagnetic data (Helsinki, Saint-Petersburg, Potsdam, and Ekaterinburg) show the same patterns. This suggests that the reliability of the proxies is sufficient to study the IMF in the past. The large-scale organization of the IMF polarities, the so-called sector structure, reveals semi-centennial north-south displacements of the heliospheric current sheet (HCS).


2020 ◽  
Author(s):  
Peter Stauning

Abstract. The only published description of the solar wind sector (SS) term used for the reference level in the post-event and real-time derivation of the Polar Cap (PC) indices, PCN (North) and PCS (South), in the version endorsed by the International Association for Geomagnetism and Aeronomy (IAGA) is found in the commented publication, Janzhura and Troshichev (2011): Identification of the IMF sector structure in near-real time by ground magnetic data, Annales Geophysicae, 29, 1491–1500. Actually, the publication has served as basis for the index endorsement by IAGA in 2013. However, neither the illustrations nor the results presented there have been derived by the specified near-real time method. Figs. 1, 6, 7, and 8 display values derived by post-event calculations based on daily medians smoothed over 7 days centred on the day of interest. Figs. 2, 3, and 4 display observed values smoothed over 7 days, while the remaining Fig. 5 displays averages over 4 months. In summary, there are strong disagreements between indications in the title, abstract, and statements in the text compared to the actual results and their illustrations.


2008 ◽  
Vol 113 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. M. Du ◽  
W. Y. Xu ◽  
X. S. Feng

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