Articles | Volume 33, issue 5
https://doi.org/10.5194/angeo-33-573-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-33-573-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Regular paper
| 
28 May 2015
Regular paper |
| 28 May 2015
Latitude dependence of long-term geomagnetic activity and its solar wind drivers
M. Myllys
CORRESPONDING AUTHOR
Department of Physics, University of Helsinki, Helsinki, P.O. Box 64, Finland
N. Partamies
Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
Department of Arctic Geophysics, The University Centre in Svalbard, Longyearbyen, Norway
L. Juusola
Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
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Noora Partamies, James M. Weygand, and Liisa Juusola
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Large-scale undulations of the diffuse aurora boundary, auroral omega bands, have been studied based on 438 omega-like structures identified over Fennoscandian Lapland from 1996 to 2007. The omegas mainly occurred in the post-magnetic midnight sector, in the region between oppositely directed ionospheric field-aligned currents, and during substorm recovery phases. The omega bands were observed during substorms, which were more intense than the average substorm in the same region.
Fred Sigernes, Pål Gunnar Ellingsen, Noora Partamies, Mikko Syrjäsuo, Pål Brekke, Silje Eriksen Holmen, Arne Danielsen, Bernt Olsen, Xiangcai Chen, Margit Dyrland, Lisa Baddeley, Dag Arne Lorentzen, Marcus Aleksander Krogtoft, Torstein Dragland, Hans Mortensson, Lisbeth Smistad, Craig J. Heinselman, and Shadia Habbal
Geosci. Instrum. Method. Data Syst., 6, 9–14, https://doi.org/10.5194/gi-6-9-2017, https://doi.org/10.5194/gi-6-9-2017, 2017
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Yann Pfau-Kempf, Heli Hietala, Steve E. Milan, Liisa Juusola, Sanni Hoilijoki, Urs Ganse, Sebastian von Alfthan, and Minna Palmroth
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We have simulated the interaction of the solar wind – the charged particles and magnetic fields emitted by the Sun into space – with the magnetic field of the Earth. The solar wind flows supersonically and creates a shock when it encounters the obstacle formed by the geomagnetic field. We have identified a new chain of events which causes phenomena in the downstream region to eventually cause perturbations at the shock and even upstream. This is confirmed by ground and satellite observations.
Tuomas Savolainen, Daniel Keith Whiter, and Noora Partamies
Geosci. Instrum. Method. Data Syst., 5, 305–314, https://doi.org/10.5194/gi-5-305-2016, https://doi.org/10.5194/gi-5-305-2016, 2016
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In this paper we describe a new method for recognition of digits in seven-segment displays. The method is used for adding date and time information to a dataset consisting of about 7 million auroral all-sky images taken during the time period of 1973–1997 at camera stations centred around Sodankylä observatory in Northern Finland. In each image there is a clock display for the date and time together with the reflection of the whole night sky through a spherical mirror.
Johannes Norberg, Lassi Roininen, Antti Kero, Tero Raita, Thomas Ulich, Markku Markkanen, Liisa Juusola, and Kirsti Kauristie
Geosci. Instrum. Method. Data Syst., 5, 263–270, https://doi.org/10.5194/gi-5-263-2016, https://doi.org/10.5194/gi-5-263-2016, 2016
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The Sodankylä Geophysical Observatory has been producing ionospheric tomography data since 2003. Based on these data, one solar cycle of ionospheric vertical total electron content (VTEC) estimates is constructed. The measurements are compared against the IRI-2012 model, F10.7 solar flux index and sunspot number data. Qualitatively the tomographic VTEC estimate corresponds to reference data very well, but the IRI-2012 model are on average 40 % higher of that of the tomographic results.
Kirsti Kauristie, Minna Myllys, Noora Partamies, Ari Viljanen, Pyry Peitso, Liisa Juusola, Shabana Ahmadzai, Vikramjit Singh, Ralf Keil, Unai Martinez, Alexej Luginin, Alexi Glover, Vicente Navarro, and Tero Raita
Geosci. Instrum. Method. Data Syst., 5, 253–262, https://doi.org/10.5194/gi-5-253-2016, https://doi.org/10.5194/gi-5-253-2016, 2016
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M. Myllys, E. Kilpua, and T. Pulkkinen
Ann. Geophys., 33, 845–855, https://doi.org/10.5194/angeo-33-845-2015, https://doi.org/10.5194/angeo-33-845-2015, 2015
K. Andréeová, L. Juusola, E. K. J. Kilpua, and H. E. J. Koskinen
Ann. Geophys., 32, 1293–1302, https://doi.org/10.5194/angeo-32-1293-2014, https://doi.org/10.5194/angeo-32-1293-2014, 2014
B. J. Jackel, C. Unick, M. T. Syrjäsuo, N. Partamies, J. A. Wild, E. E. Woodfield, I. McWhirter, E. Kendall, and E. Spanswick
Geosci. Instrum. Method. Data Syst., 3, 71–94, https://doi.org/10.5194/gi-3-71-2014, https://doi.org/10.5194/gi-3-71-2014, 2014
D. K. Whiter, B. Gustavsson, N. Partamies, and L. Sangalli
Geosci. Instrum. Method. Data Syst., 2, 131–144, https://doi.org/10.5194/gi-2-131-2013, https://doi.org/10.5194/gi-2-131-2013, 2013
N. Partamies, L. Juusola, E. Tanskanen, and K. Kauristie
Ann. Geophys., 31, 349–358, https://doi.org/10.5194/angeo-31-349-2013, https://doi.org/10.5194/angeo-31-349-2013, 2013
