Regular paper 29 Nov 2018
Regular paper | 29 Nov 2018
The asymmetric geospace as displayed during the geomagnetic storm on 17 August 2001
Nikolai Østgaard et al.
Related authors
Alejandro Luque, Francisco José Gordillo-Vázquez, Dongshuai Li, Alejandro Malagón-Romero, Francisco Javier Pérez-Invernón, Anthony Schmalzried, Sergio Soler, Olivier Chanrion, Matthias Heumesser, Torsten Neubert, Víctor Reglero, and Nikolai Østgaard
Geosci. Model Dev., 13, 5549–5566, https://doi.org/10.5194/gmd-13-5549-2020, https://doi.org/10.5194/gmd-13-5549-2020, 2020
Short summary
Short summary
Lightning flashes are often recorded from space-based platforms. Besides being valuable inputs for weather forecasting, these observations also enable research into fundamental questions regarding lightning physics. To exploit them, it is essential to understand how light propagates from a lightning flash to a space-based observation instrument. Here, we present an open-source software tool to model this process that extends on previous work and overcomes some of the existing limitations.
David Sarria, Casper Rutjes, Gabriel Diniz, Alejandro Luque, Kevin M. A. Ihaddadene, Joseph R. Dwyer, Nikolai Østgaard, Alexander B. Skeltved, Ivan S. Ferreira, and Ute Ebert
Geosci. Model Dev., 11, 4515–4535, https://doi.org/10.5194/gmd-11-4515-2018, https://doi.org/10.5194/gmd-11-4515-2018, 2018
Short summary
Short summary
We evaluate three models (Geant4, REAM, GRRR) used in the field of high-energy atmospheric physics that are able to simulate relativistic runaway electron avalanches. Several models have been used by the community, but there was, up until now, no study evaluating their consistency in this context. We conclude that there are no major differences to report, and we discuss minor ones. We also provide advice on how to properly set up the general purpose code (Geant4) in this context.
Casper Rutjes, David Sarria, Alexander Broberg Skeltved, Alejandro Luque, Gabriel Diniz, Nikolai Østgaard, and Ute Ebert
Geosci. Model Dev., 9, 3961–3974, https://doi.org/10.5194/gmd-9-3961-2016, https://doi.org/10.5194/gmd-9-3961-2016, 2016
Short summary
Short summary
High energy atmospheric physics includes terrestrial gamma-ray flashes, electron–positron beams and gamma-ray glows from thunderstorms. It requires appropriate models for the interaction of energetic particles with the atmosphere. We benchmark general purpose and custom-made codes against each other. We focus on basic tests, namely on the evolution of particles through air in the absence of electric and magnetic fields, providing a first benchmark for present and future custom-made codes.
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.
Alejandro Luque, Francisco José Gordillo-Vázquez, Dongshuai Li, Alejandro Malagón-Romero, Francisco Javier Pérez-Invernón, Anthony Schmalzried, Sergio Soler, Olivier Chanrion, Matthias Heumesser, Torsten Neubert, Víctor Reglero, and Nikolai Østgaard
Geosci. Model Dev., 13, 5549–5566, https://doi.org/10.5194/gmd-13-5549-2020, https://doi.org/10.5194/gmd-13-5549-2020, 2020
Short summary
Short summary
Lightning flashes are often recorded from space-based platforms. Besides being valuable inputs for weather forecasting, these observations also enable research into fundamental questions regarding lightning physics. To exploit them, it is essential to understand how light propagates from a lightning flash to a space-based observation instrument. Here, we present an open-source software tool to model this process that extends on previous work and overcomes some of the existing limitations.
Thomas B. Leyser, Björn Gustavsson, Theresa Rexer, and Michael T. Rietveld
Ann. Geophys., 38, 297–307, https://doi.org/10.5194/angeo-38-297-2020, https://doi.org/10.5194/angeo-38-297-2020, 2020
Short summary
Short summary
Powerful radio waves transmitted into the ionosphere give the strongest turbulence effects in geomagnetic zenith, antiparallel to the magnetic field in the Northern Hemisphere. Our results obtained with the EISCAT (European Incoherent SCATter association) Heating facility in Norway and the EISCAT UHF incoherent scatter radar together with modelling suggest that the pump wave propagates in the L mode, rather than in the O mode that is usually assumed to be involved in such experiments.
David Sarria, Casper Rutjes, Gabriel Diniz, Alejandro Luque, Kevin M. A. Ihaddadene, Joseph R. Dwyer, Nikolai Østgaard, Alexander B. Skeltved, Ivan S. Ferreira, and Ute Ebert
Geosci. Model Dev., 11, 4515–4535, https://doi.org/10.5194/gmd-11-4515-2018, https://doi.org/10.5194/gmd-11-4515-2018, 2018
Short summary
Short summary
We evaluate three models (Geant4, REAM, GRRR) used in the field of high-energy atmospheric physics that are able to simulate relativistic runaway electron avalanches. Several models have been used by the community, but there was, up until now, no study evaluating their consistency in this context. We conclude that there are no major differences to report, and we discuss minor ones. We also provide advice on how to properly set up the general purpose code (Geant4) in this context.
Minna Palmroth, Sanni Hoilijoki, Liisa Juusola, Tuija I. Pulkkinen, Heli Hietala, Yann Pfau-Kempf, Urs Ganse, Sebastian von Alfthan, Rami Vainio, and Michael Hesse
Ann. Geophys., 35, 1269–1274, https://doi.org/10.5194/angeo-35-1269-2017, https://doi.org/10.5194/angeo-35-1269-2017, 2017
Short summary
Short summary
Much like solar flares, substorms occurring within the Earth's magnetic domain are explosive events that cause vivid auroral displays. A decades-long debate exists to explain the substorm onset. We devise a simulation encompassing the entire near-Earth space and demonstrate that detailed modelling of magnetic reconnection explains the central substorm observations. Our results help to understand the unpredictable substorm process, which will significantly improve space weather forecasts.
Casper Rutjes, David Sarria, Alexander Broberg Skeltved, Alejandro Luque, Gabriel Diniz, Nikolai Østgaard, and Ute Ebert
Geosci. Model Dev., 9, 3961–3974, https://doi.org/10.5194/gmd-9-3961-2016, https://doi.org/10.5194/gmd-9-3961-2016, 2016
Short summary
Short summary
High energy atmospheric physics includes terrestrial gamma-ray flashes, electron–positron beams and gamma-ray glows from thunderstorms. It requires appropriate models for the interaction of energetic particles with the atmosphere. We benchmark general purpose and custom-made codes against each other. We focus on basic tests, namely on the evolution of particles through air in the absence of electric and magnetic fields, providing a first benchmark for present and future custom-made codes.
Yann Pfau-Kempf, Heli Hietala, Steve E. Milan, Liisa Juusola, Sanni Hoilijoki, Urs Ganse, Sebastian von Alfthan, and Minna Palmroth
Ann. Geophys., 34, 943–959, https://doi.org/10.5194/angeo-34-943-2016, https://doi.org/10.5194/angeo-34-943-2016, 2016
Short summary
Short summary
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.
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.
M. Volwerk, N. André, C. S. Arridge, C. M. Jackman, X. Jia, S. E. Milan, A. Radioti, M. F. Vogt, A. P. Walsh, R. Nakamura, A. Masters, and C. Forsyth
Ann. Geophys., 31, 817–833, https://doi.org/10.5194/angeo-31-817-2013, https://doi.org/10.5194/angeo-31-817-2013, 2013
Related subject area
Subject: Magnetosphere & space plasma physics | Keywords: Solar wind–magnetosphere interactions
From the Sun to Earth: effects of the 25 August 2018 geomagnetic storm
GUMICS-4 analysis of interplanetary coronal mass ejection impact on Earth during low and typical Mach number solar winds
Local time extent of magnetopause reconnection using space–ground coordination
Transfer entropy and cumulant-based cost as measures of nonlinear causal relationships in space plasmas: applications to Dst
Mirko Piersanti, Paola De Michelis, Dario Del Moro, Roberta Tozzi, Michael Pezzopane, Giuseppe Consolini, Maria Federica Marcucci, Monica Laurenza, Simone Di Matteo, Alessio Pignalberi, Virgilio Quattrociocchi, and Piero Diego
Ann. Geophys., 38, 703–724, https://doi.org/10.5194/angeo-38-703-2020, https://doi.org/10.5194/angeo-38-703-2020, 2020
Short summary
Short summary
This paper presents a comprehensive analysis of the solar event that occurred on 25 August 2018. This kind of comprehensive analysis plays a key role in better understanding the complexity of the processes occurring in the Sun–Earth system determining the geoeffectiveness of manifestations of solar activity. The analysis presented here shows for the first time a direct link between characteristics of solar perturbation, the magnetosphere–ionosphere system response and space weather effects.
Antti Lakka, Tuija I. Pulkkinen, Andrew P. Dimmock, Emilia Kilpua, Matti Ala-Lahti, Ilja Honkonen, Minna Palmroth, and Osku Raukunen
Ann. Geophys., 37, 561–579, https://doi.org/10.5194/angeo-37-561-2019, https://doi.org/10.5194/angeo-37-561-2019, 2019
Short summary
Short summary
We study how the Earth's space environment responds to two different amplitude interplanetary coronal mass ejection (ICME) events that occurred in 2012 and 2014 by using the GUMICS-4 global MHD model. We examine local and large-scale dynamics of the Earth's space environment and compare simulation results to in situ data. It is shown that during moderate driving simulation agrees well with the measurements; however, GMHD results should be interpreted cautiously during strong driving.
Ying Zou, Brian M. Walsh, Yukitoshi Nishimura, Vassilis Angelopoulos, J. Michael Ruohoniemi, Kathryn A. McWilliams, and Nozomu Nishitani
Ann. Geophys., 37, 215–234, https://doi.org/10.5194/angeo-37-215-2019, https://doi.org/10.5194/angeo-37-215-2019, 2019
Short summary
Short summary
Magnetopause reconnection is a process whereby the Sun explosively transfers energy to the Earth. Whether the process is spatially patchy or spatially continuous and extended has been under long debate. We use space–ground coordination to overcome the limitations of previous studies and reliably interpret spatial extent. Our result strongly indicates that both patchy and extended reconnection is possible and, interestingly, that extended reconnection grows from a localized patch via spreading.
Jay R. Johnson, Simon Wing, and Enrico Camporeale
Ann. Geophys., 36, 945–952, https://doi.org/10.5194/angeo-36-945-2018, https://doi.org/10.5194/angeo-36-945-2018, 2018
Short summary
Short summary
The magnetospheric response to the solar wind is nonlinear. Information theoretical tools are able to characterize the nonlinearities in the system. We show that nonlinear significance of Dst peaks at lags of 3–12 hours which can be attributed to VBs, which also exhibits similar behavior. However, the nonlinear significance that peaks at lags of 25, 50, and 90 hours can be attributed to internal dynamics, which may be related to the relaxation of the ring current.
Cited articles
Amm, O.: Ionospheric elementary current systems in spherical coordinates and
their application, J. Geomag. Geoelectr., 947–955, 1997. a
Amm, O., Grocott, A., Lester, M., and Yeoman, T. K.: Local determination of
ionospheric plasma convection from coherent scatter radar data using the
SECS technique, J. Geophys. Res., 115, https://doi.org/10.1029/2009JA014832, 2010. a, b
Borg, A. L., Østgaard, N., Pedersen, A., Øieroset, M., Phan, T. D.,
Germany, G., Åsnes, A., Lewis, W., Stadsnes, J., Lucek, E. A., Rème,
H., and Moukis, C.: Simultaneous observations of magnetotail reconnection and
bright X-ray aurora on 2. October 2002, J. Geophys. Res., 112, A06215,
https://doi.org/10.1029/2006JA011913, 2007. a
Browett, S. D., Fear, R. C., Grocott, A., and Milan, S. E.: Timescales for
the
penetration of IMF By into the Earth's magnetotail, J. Geophys. Res.,
122, 579–593, https://doi.org/10.1002/2016JA023198, 2017. a
Caan, M. N., McPherron, R. L., and Russell, C. T.: Substorm and
interplanetary
magnetic field effects on the geomagnetic tail lobes, J. Geophys. Res., 80,
191–194, 1975. a
Chisham, G., Coleman, I. J., Freeman, M. P., and Pinnock, M.: Ionospheric
signatures of split reconnection X-lines during conditions of IMF Bz<0
and : Evidence for the antiparallel merging hypothesis, J.
Geophys. Res., 107, https://doi.org/10.1029/2001JA009124, 2002. a
Cowley, S. W. H.: Magnetospheric asymmetries associated with the
Y-component
of the IMF, Planet. Space Sci., 29, 79–96, 1981. a
Echer, E., Korth, A., Zong, Q. G., Fränz, Gonzalez, W. D., Guarnieri,
F. L., Fu, S. Y., and Rème, H.: Cluster observations of O+
escape in the magnetotail due to shock compression effects during the initial
phase of the magnetic storm on 17 August 2001, J. Geophys. Res., 113,
A05209,
https://doi.org/10.1029/2007JA012624, 2008. a
Frank, L. A. and Sigwarth, J. B.: Simultaneous images of the northern and
southern auroras from the Polar spacecraft: An auroral substorm, J.
Geophys. Res., 108, 8015, https://doi.org/10.1029/2002JA009356, 2003. a
Frank, L. A., Sigwarth, J. B., Craven, J. D., Cravens, J. P., Dolan, J. S.,
Dvorsky, M. R., Hardebeck, P. K., Harvey, J. D., and Muller, D. W.: The
visible imaging system (VIS) for the Polar spacecraft, Space Sci. Rev.,
71, 297–328, 1995. a
Frey, H. U., Mende, S. B., Immel, T. J., Lu, G., Bonnell, J., Fusilier,
S. A.,
Mende, S. B., , Hubert, B., Østgaard, N., and Le, G.: Properties of
localized, high latitude, dayside aurora, J. Geophys. Res., 108, 8008,
https://doi.org/10.1029/2002JA009356, 2003b. a, b, c
Frey, H. U., Østgaard, Immel, T. J., Korth, H., and Mende, S. B.: Seasonal
dependence of localized, high-latitude dayside aurora (HiLDA), J. Geophys.
Res., 109, A04303, https://doi.org/10.1029/2003JA010293, 2004. a, b, c
Gjerloev, J. W.: The SuperMAG data processing technique, J. Geophys. Res.,
117, A09213, https://doi.org/10.1029/2012JA017683, 2012. a
Gosling, J. T., McComas, D. J., Thomsen, M. F., Bame, S. J., and Russell,
C. T.: The warped neutral sheet and plasma sheet in the near-Earth
geomagnetic tail, J. Geophys. Res., 91, 7093–7099, 1986. a
Greenwald, R. A., Baker, K. B., Dudeney, J. R., Pinnock, M., Jones, T. B.,
Thomas, E. C., Villain, J. P., Cerisier, J. C., Senior, C., Hanuise, C.,
Hunsucker, R. D., Sofko, G., Koehler, J., Nielsen, E., Pellinen, R., Walker,
A. D. M., Sato, N., and Yamagish, H.: DARN/SuperDARN, Space Sci. Rev., 71,
761–796, https://doi.org/10.1007/BF00751350, 1995. a
Grocott, A., Milan, S. E., Yeoman, T. K., Sato, N., Yukimatu, A. S., and
Wild,
J. A.: Superposed epoch analysis of the ionospheric convection evolution
during substorms: IMF BY dependence, J. Geophys. Res., 115, A00106,
https://doi.org/10.1029/2010JA015728, 2010. a, b
Hau, L. N. and Erickson, G. M.: Penetration of the Interplanetary Magnetic
Field BY into Earth's Plasma Sheet, J. Geophys. Res., 100,
21745–21751, 1995. a
Heppner, J. and Maynard, N.: Empirical High-Latitude Electric Field Models,
J.
Geophys. Res., 101, 10,773–10,791, 1987. a
Huttunen, K. E. J., Slavin, J., Collier, M., Koskinen, H. E. J., Szabo, A.,
Tanskanen, E., Balogh, A., Lucek, E., and Rème, H.: Cluster observations
of sudden impulses in the magnetotail caused by interplanetary shocks and
pressure increases, Ann. Geophys., 23, 609–624,
https://doi.org/10.5194/angeo-23-609-2005, 2005. a
Juusola, L., Østgaard, N., Tanskanen, E., Partamies, N., and Snekvik, K.:
Earthward Plasma Sheet Flows During Substorm Phases, J. Geophys. Res., 116,
A10228,
https://doi.org/10.1029/2011JA016852, 2011. a
King, J. H. and Papitashvili, N. E.: Solar wind spatial scales in and
comparisons of hourly Wind and ACE plasma and magnetic field data, J.
Geophys. Res., 110, A02104, https://doi.org/10.1029/2004JA010649, 2005. a
Kozlovsky, A., Turunen, T., Koustov, A., and Parks, G.: IMF BY effects
in
the magnetospheric convection on closed magnetic field lines, Geophys. Res.
Lett., 30, 1–4, https://doi.org/10.1029/2003GL018457, 2003. a
Laundal, K. M. and Richmond, A. D.: Magnetic Coordinate Systems, Space
Sci.
Rev., 206, 27–59, https://doi.org/10.1007/s11214-016-0275-y, 2016. a
Laundal, K. M., Østgaard, N., Snekvik, K., and Frey, H. U.:
Inter-hemispheric observations of emerging polar cap asymmetries, J. Geophys.
Res., 115, A07230, https://doi.org/10.1029/2009JA015160, 2010. a
Laundal, K. M., Haaland, S. E., Lehtinen, N., Gjerloev, J. W., Østgaard,
N.,
Tenfjord, P., Reistad, J. P., Snekvik, K., Milan, S. E., Ohtani, S., and
Anderson, B. J.: Birkeland current effects on high-latitude ground magnetic
field perturbations, Geophys. Res. Lett., 42, 7248–7254,
https://doi.org/10.1002/2015GL065776, 2015. a
Laundal, K. M., Gjerloev, J. W., Østgaard, N., Reistad, J. P., Haaland,
S. E., Snekvik, K., Tenfjord, P., Ohtani, S., and Milan, S. E.: The impact of
sunlight on high-latitude equivalent currents, J. Geophys. Res., 121,
1–12,
https://doi.org/10.1002/2015JA022236, 2016. a
Liou, K. and Newell, P. T.: On the azimuthal location of auroral breakup:
Hemispheric asymmetry, Geophys. Res. Lett., 37, L23103, https://doi.org/10.1029/2010GL045537,
2010. a, b, c, d
Liou, K., Newell, P. T., and Meng, C. I.: Seasonal effects on auroral
particle
acceleration and precipitation, J. Geophys. Res., 106, 5531–5542,
2001a. a
Liou, K., Newell, P. T., Sibeck, D. G., Meng, C. I., Brittnacher, M., and
Parks, G.: Observation of IMF and seasonal effects in the location of
auroral substorm onset, J. Geophys. Res., 106, 5799–5810,
2001b. a
Longley, W., Reiff, P., Daou, A. G., and Hairston, M.: Conjugate Aurora
Location During a Strong IMF BY Storm, in: Dawn-Dusk Asymmetries
in Planetary Plasma Environments, Geophysical Monograph 230, edited by:
Haaland, S., Runov, A., and Forsyth, C., AGU, Washington, DC, 283–292, 2017a. a
Longley, W., Reiff, P., Reistad, J. P., and Østgaard, N.: Magnetospheric
Model Performance during Conjugate Aurora, in:
Magnetosphere-Ionosphere Coupling in the Solar System, Geophysical Monograph
222, edited by: Chappell, C. R., Schunk, R. W., Banks, P. M., Burch, J. L.,
and Thorne, R. M., AGU, Washington, DC, 227–233, 2017b. a
Lühr, H., Warnecke, J. F., and Rother, M. K. A.: An algorithm for
estimating field-aligned currents from single spacecraft magnetic field
measurements: A diagnostic tool applied to Freja satellite data, IEEE
T. Geosci. Remote Sens., 34, 1369–1376, 1996. a
Lyon, J. G., Fedder, J. A., and Mobarry, C. M.: The Lyon-Fedder-Mobarry
(LFM) global MHD magnetospheric simulation code, J. Atmos. Sol.-Terr.
Phys., 66, 1333–1350, https://doi.org/10.1016/j.jastp.2004.03.020, 2005. a
Mende, S. B., Heetderks, H., Frey, H. U., Lampton, M., Geller, S. P.,
Habraken,
S., Renotte, E., Jamar, C., Rochus, P., Spann, J., Dougani, H., Fusilier,
S. A., Gerard, J. C., Galdstone, R., Murphree, S., and l. Cogger: Far
ultraviolet imaging from the IMAGE spacecraft. 1. System design, Space Sci.
Rev., 91, 243–270, 2000. a
Merkin, V. G. and Lyon, J. G.: Effects of the low-latitude ionospheric
boundary
condition on the global magnetosphere, J. Geophys. Res., 115, 1333–1350,
https://doi.org/10.1029/2010JA015461, 2010. a
Milan, S. E., Lester, M., Cowley, S. W. H., and Brittnacher, M.: Dayside
convection and auroral morphology during an interval of northward
interplanetary magnetic field, Ann. Geophys., 18, 436–444,
https://doi.org/10.1007/s00585-000-0436-9, 2000. a
Motoba, T., Hosokawa, K., Sato, N., Kadokura, A., and Bjornsson, G.: Varying
interplanetary magnetic field BY effects on interhemispheric conjugate
auroral features during a weak substorm, J. Geophys. Res., 115, A09210,
https://doi.org/10.1029/2010JA015369, 2010. a, b, c
Ohtani, S. and Yoshikawa, A.: The initiation of poleward boundary
intensification of airoral emission by fast polar cap flows: A new
interpretation based on ionospheric polarization, J. Geophys. Res., 121,
10910–10928, https://doi.org/10.1002/2016JA023143, 2016. a, b
Ohtani, S., Wing, S., Ueno, G., and Higuchi, T.: Dependence of premidnight
field-aligned currents and particle precipitation on solar illumination,
J. Geophys. Res.-Space, 114, A12205,
https://doi.org/10.1029/2009JA014115, 2009. a
Øieroset, M., Lin, R. P., Phan, T. D., Larson, D. E., and Bale, S. D.:
Evidence for electron acceleration up to ∼300 keV in the magnetotail
reconnection diffusion region of Earth's magnetotail, Phys. Rev. Lett., 89,
195001, https://doi.org/10.1103/PhysRevLett.89.195001, 2002. a
Østgaard, N., Mende, S. B., Frey, H. U., Immel, T. J., Frank, L. A.,
Sigwarth, J. B., and Stubbs, T. J.: Interplanetary magnetic field control of
the location of substorm onset and auroral features in the conjugate
hemispheres, J. Geophys. Res., 109, A07204, https://doi.org/10.1029/2003JA010370, 2004. a, b, c
Østgaard, N., Tsyganenko, N. A., Mende, S. B., Frey, H. U., Immel, T. J.,
Fillingim, M., Frank, L. A., and Sigwarth, J. B.: Observations and model
predictions of auroral substorm asymmetries in the conjugate hemispheres,
Geophys. Res. Lett., 32, L05111, https://doi.org/10.1029/2004GL022166, 2005. a, b
Østgaard, N., Snekvik, K., Borg, A. L., Åsnes, A., Pedersen, A.,
Øieroset, M., Phan, T., and Haaland, S. E.: Can magnetotail reconnection
produce the auroral intensities observed in the conjugate ionosphere, J.
Geophys. Res., 114, A06204, https://doi.org/10.1029/2009JA014185, 2009. a
Østgaard, N., Humberset, B. K., and Laundal, K. M.: Evolution of auroral
asymmetries in the conjugate hemispheres during two substorms, Geophys. Res.
Lett., 38, L03101, https://doi.org/10.1029/2010GL046057, 2011a. a, b
Østgaard, N., Laundal, K. M., Juusola, L., Åsnes, A., Håland,
S. E.,
and Weygand, J. M.: Interhemispherical asymmetry of substorm onset locations
and the interplanetary magnetic field, Geophys. Res. Lett., 38, L08104,
https://doi.org/10.1029/2011GL046767, 2011b. a
Østgaard, N., Reistad, J. P., Tenfjord, P., Laundal, K. M., Rexer, T.,
Haaland, S. E., Snekvik, K., Hesse, M., Milan, S. E., and Ohma, A.: Video:
The asymmetric geospace as displayed during
the geomagnetic storm on August 17, 2001,
https://doi.org/10.5281/zenodo.1488622, 2018. a
Petrukovich, A. A.: Origin of plasma sheet BY, J. Geophys. Res.,
116, A07217,
https://doi.org/10.1029/2010JA016386, 2011. a
Reigber, C., Lühr, H., and Schwintzer: CHAMP mission status, Adv. Space
Res., 30, https://doi.org/10.1016/S0273-1177(02)00276-4, 2002. a
Reistad, J. P., Østgaard, N., Laundal, K. M., Haaland, S., Tenfjord, P.,
Snekvik, K., Oksavik, K., and Milan, S. E.: Intensity asymmetries in the dusk sector
of the poleward auroral oval
due to IMF Bx, J. Geophys. Res., 119, 9497–9507,
https://doi.org/10.1002/2014JA020216, 2014. a
Reistad, J. P., Østgaard, N., Tenfjord, P., Laundal, K. M., Snekvik, K.,
Haaland, S., Milan, S. E., Oksavik, K., Frey, H. U., and Grocott, A.: Dynamic
effects of restoring footprint symmetry on closed magnetic field-lines, J.
Geophys. Res., 121, 1–15, https://doi.org/10.1002/2015JA022058, 2016. a, b, c
Rich, F. J. and Hairston, M.: Large scale convection patterns observed by
DMSP,
J. Geophys. Res., 99, 3827–3844, 1994. a
Ridley, A., Clauer, C., Lu, G., and Papitashvili, V.: A statistical study of
the ionospheric convection response to changing interplanetary magnetic field
conditions using the assimilative mapping of ionospheric electrodynamics
technique, J. Geophys. Res., 103, 4023–4039, https://doi.org/10.1029/97JA03328, 1998. a
Rong, Z. J., Lui, A. T. Y., Wan, W. X., Yang, Y. Y., Shen, C., Petrukovich,
A. A., Zhang, Y. C., Zhang, T., and Wei, Y.: Time delay of interplanetary
magnetic field penetration into Earth's magnetotail, J. Geophys. Res.,
120, 3406–3414,
https://doi.org/10.1002/2014JA020452, 2015. a, b
Snekvik, K., Østgaard, N., Tenfjord, P., Reistad, J. P., Laundal, K. M.,
Milan, S. E., and Haaland, S.: Dayside and magnetic field responses at 780 km
altitude to dayside reconnection, J. Geophys. Res., 122, 1670–1689,
https://doi.org/10.1002/2016JA023177, 2017.
a
Tenfjord, P., Østgaard, N., Reistad, J. P., Laundal, K. M., Haaland, S.,
Snekvik, K., and Milan, S. E.: How the IMF By induces a By component in the
closed magnetosphere and how it leads to asymmetric currents and convection
patterns in the two hemispheres, J. Geophys. Res., 120, 1–17,
https://doi.org/10.1002/2015JA021579, 2015. a, b, c, d, e, f, g, h
Tenfjord, P., Østgaard, N., Strangeway, R., Haaland, S., Snekvik, K.,
Laundal, K. M., Reistad, J. P., and Milan, S. E.: Magnetospheric response and
reconfiguration times following IMF By reversals, J. Geophys. Res.,
122, 1–15, https://doi.org/10.1002/2016JA023018, 2017. a, b
Tenfjord, P., Østgaard, N., Haaland, S., Snekvik, K., Laundal, K. M.,
Reistad, J. P., Strangeway, R., Milan, S. E., Hesse, M., and Ohma, A.: How
the IMF By Induces a Local By Component During Northward
IMF Bz and Characteristic Timescales, J. Geophys. Res., 123,
1–16,
https://doi.org/10.1002/2018JA025186, 2018. a, b
Tsyganenko, N. A.: A model of the near magnetosphere with a dawn-dusk
asymmetry
1. Mathematical structure, J. Geophys. Res., 107, 1179,
https://doi.org/10.1029/2001JA000219, 2002a. a
Tsyganenko, N. A.: A model of the near magnetosphere with a dawn-dusk
asymmetry
2. Parametrization and fitting to observations, J. Geophys. Res., 107, 1179,
https://doi.org/10.1029/2001JA000220, 2002b. a
Wang, H., Lühr, H., Ma, S. Y., and Frey, H. U.: Interhemispheric
comparison of average substorm onset locations: evidence for deviation from
conjugacy, Ann. Geophys., 25, 989–999,
https://doi.org/10.5194/angeo-25-989-2007, 2007. a
Wing, S., Newell, P. T., Sibeck, D. G., and Baker, K. B.: A large statistical
study of the entry of interplanetary magnetic field component into the
magnetosphere, Geophys. Res. Lett., 22, 2083–2086, 1995. a
Short summary
In this paper we take advantage of having two auroral imaging missions giving simultaneous data of both the southern and northern aurora. Combined with all available in situ measurements from space and global ground-based networks, we explore the asymmetric behavior of geospace. We find large auroral asymmetries and different reconnection geometry in the two hemispheres. During substorm expansion phase asymmetries are reduced.
In this paper we take advantage of having two auroral imaging missions giving simultaneous data...