Articles | Volume 33, issue 8
https://doi.org/10.5194/angeo-33-1059-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/angeo-33-1059-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Regular paper
| 
31 Aug 2015
Regular paper |
| 31 Aug 2015
Energy–latitude dispersion patterns near the isotropy boundaries of energetic protons
St. Petersburg State University, Ulyanovskaya 1, 198504 St. Petersburg, Russia
S. A. Chernyaeva
St. Petersburg State University, Ulyanovskaya 1, 198504 St. Petersburg, Russia
S. V. Apatenkov
St. Petersburg State University, Ulyanovskaya 1, 198504 St. Petersburg, Russia
N. Y. Ganushkina
Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI, USA
Earth Observation, Finnish Meteorological Institute, Helsinki, Finland
S. V. Dubyagin
Earth Observation, Finnish Meteorological Institute, Helsinki, Finland
Related authors
V. A. Sergeev, I. A. Chernyaev, V. Angelopoulos, and N. Y. Ganushkina
Ann. Geophys., 33, 1485–1493, https://doi.org/10.5194/angeo-33-1485-2015, https://doi.org/10.5194/angeo-33-1485-2015, 2015
Short summary
Short summary
Adaptive magnetospheric models based on THEMIS magnetic observations made at 6-9Re in the nightside magnetosphere are used to map the magnetically conjugate 30 and 80keV proton isotropy boundaries (IBs) to investigate the value of Kib=Rc/rc (magnetic curvature radius to particle gyroradius) in the neutral sheet at the IB generation place. For the most accurate mapping, the group Kib spread spans from 4 to 32; its median value is ~13, slightly larger than Kib8 expected for current sheet scatter.
A. V. Nikolaev, V. A. Sergeev, N. A. Tsyganenko, M. V. Kubyshkina, H. Opgenoorth, H. Singer, and V. Angelopoulos
Ann. Geophys., 33, 505–517, https://doi.org/10.5194/angeo-33-505-2015, https://doi.org/10.5194/angeo-33-505-2015, 2015
Short summary
Short summary
In this study we use two-loop model SCW (SCW2L) to quantitatively investigate distortion of the ionospheric footpoint pattern in response to changes of different SCW2L parameters. Calculation results show that SCW-related footprint shifts result in formation of auroral bulge and westward travelling surge and may contribute to rotation of auroral streamers, and that SCW2L combined with the AM03 model nicely describes the azimuthal progression and the observed magnitude of the auroral expansion.
Emilia Kilpua, Liisa Juusola, Maxime Grandin, Antti Kero, Stepan Dubyagin, Noora Partamies, Adnane Osmane, Harriet George, Milla Kalliokoski, Tero Raita, Timo Asikainen, and Minna Palmroth
Ann. Geophys., 38, 557–574, https://doi.org/10.5194/angeo-38-557-2020, https://doi.org/10.5194/angeo-38-557-2020, 2020
Short summary
Short summary
Coronal mass ejection sheaths and ejecta are key drivers of significant space weather storms, and they cause dramatic changes in radiation belt electron fluxes. Differences in precipitation of high-energy electrons from the belts to the upper atmosphere are thus expected. We investigate here differences in sheath- and ejecta-induced precipitation using the Finnish riometer (relative ionospheric opacity meter) chain.
K. Kauristie, M. V. Uspensky, N. G. Kleimenova, O. V. Kozyreva, M. M. J. L. Van De Kamp, S. V. Dubyagin, and S. Massetti
Ann. Geophys., 34, 379–392, https://doi.org/10.5194/angeo-34-379-2016, https://doi.org/10.5194/angeo-34-379-2016, 2016
Short summary
Short summary
This study presents some example events in which sudden changes in the auroral activity at midnight sector seem to have an impact on the intensity of morning-sector magnetic pulsations. Mechanisms which could link these two separate regions are discussed in the paper. Sudden changes in the solar wind properties and fast westward-propagating electrons are suggested to explain the coupling between midnight-sector and morning-sector phenomena.
V. A. Sergeev, I. A. Chernyaev, V. Angelopoulos, and N. Y. Ganushkina
Ann. Geophys., 33, 1485–1493, https://doi.org/10.5194/angeo-33-1485-2015, https://doi.org/10.5194/angeo-33-1485-2015, 2015
Short summary
Short summary
Adaptive magnetospheric models based on THEMIS magnetic observations made at 6-9Re in the nightside magnetosphere are used to map the magnetically conjugate 30 and 80keV proton isotropy boundaries (IBs) to investigate the value of Kib=Rc/rc (magnetic curvature radius to particle gyroradius) in the neutral sheet at the IB generation place. For the most accurate mapping, the group Kib spread spans from 4 to 32; its median value is ~13, slightly larger than Kib8 expected for current sheet scatter.
N. Y. Ganushkina, M. W. Liemohn, S. Dubyagin, I. A. Daglis, I. Dandouras, D. L. De Zeeuw, Y. Ebihara, R. Ilie, R. Katus, M. Kubyshkina, S. E. Milan, S. Ohtani, N. Ostgaard, J. P. Reistad, P. Tenfjord, F. Toffoletto, S. Zaharia, and O. Amariutei
Ann. Geophys., 33, 1369–1402, https://doi.org/10.5194/angeo-33-1369-2015, https://doi.org/10.5194/angeo-33-1369-2015, 2015
Short summary
Short summary
A number of current systems exist in the Earth's magnetosphere. It is very difficult to identify local measurements as belonging to a specific current system. Therefore, there are different definitions of supposedly the same current, leading to unnecessary controversy. This study presents a robust collection of these definitions of current systems in geospace, particularly in the near-Earth nightside magnetosphere, as viewed from a variety of observational and computational analysis techniques.
A. V. Nikolaev, V. A. Sergeev, N. A. Tsyganenko, M. V. Kubyshkina, H. Opgenoorth, H. Singer, and V. Angelopoulos
Ann. Geophys., 33, 505–517, https://doi.org/10.5194/angeo-33-505-2015, https://doi.org/10.5194/angeo-33-505-2015, 2015
Short summary
Short summary
In this study we use two-loop model SCW (SCW2L) to quantitatively investigate distortion of the ionospheric footpoint pattern in response to changes of different SCW2L parameters. Calculation results show that SCW-related footprint shifts result in formation of auroral bulge and westward travelling surge and may contribute to rotation of auroral streamers, and that SCW2L combined with the AM03 model nicely describes the azimuthal progression and the observed magnitude of the auroral expansion.
S. Dubyagin, N. Ganushkina, S. Apatenkov, M. Kubyshkina, H. Singer, and M. Liemohn
Ann. Geophys., 31, 395–408, https://doi.org/10.5194/angeo-31-395-2013, https://doi.org/10.5194/angeo-31-395-2013, 2013
Short summary
We investigate the precipitated-to-trapped flux ratio patterns near the proton isotropy boundary (IB) using NOAA-POES observations. For 30 and 80keV proton energies, we found only 31% of events showing the dispersion pattern predicted by the non-adiabatic scattering in the tail current sheet. Most frequent pattern had no measureable IB energy dispersion (63%); structured IBs with a few Jprec/Jtrap dropouts were also usual (60%). Roles of current sheet and wave-induced scattering are discussed.
We investigate the precipitated-to-trapped flux ratio patterns near the proton isotropy boundary...
Special issue