Articles | Volume 39, issue 1
https://doi.org/10.5194/angeo-39-53-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-39-53-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
15 Jan 2021
Regular paper |
| 15 Jan 2021
| 15 Jan 2021
Ion acoustic waves near a comet nucleus: Rosetta observations at comet 67P/Churyumov–Gerasimenko
Herbert Gunell
CORRESPONDING AUTHOR
Department of Physics, Umeå University, 90187 Umeå, Sweden
Charlotte Goetz
Space Research and Technology Centre, European Space Agency,
Keplerlaan 1, 2201AZ Noordwijk, the Netherlands
Elias Odelstad
Department of Space and Plasma Physics, Royal Institute of
Technology, 10044 Stockholm, Sweden
Arnaud Beth
Department of Physics, Umeå University, 90187 Umeå, Sweden
Maria Hamrin
Department of Physics, Umeå University, 90187 Umeå, Sweden
Pierre Henri
LPC2E, CNRS, 45071 Orléans, France
Lagrange, OCA, CNRS, UCA, Nice, France
Fredrik L. Johansson
Swedish Institute of Space Physics, Box 537, 75121 Uppsala, Sweden
Hans Nilsson
Swedish Institute of Space Physics, Box 812, 98128 Kiruna, Sweden
Gabriella Stenberg Wieser
Swedish Institute of Space Physics, Box 812, 98128 Kiruna, Sweden
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Charlotte Goetz, Herbert Gunell, Fredrik Johansson, Kristie LLera, Hans Nilsson, Karl-Heinz Glassmeier, and Matthew G. G. T. Taylor
Ann. Geophys., 39, 379–396, https://doi.org/10.5194/angeo-39-379-2021, https://doi.org/10.5194/angeo-39-379-2021, 2021
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Boundaries in the plasma around comet 67P separate regions with different properties. Many have been identified, including a new boundary called an infant bow shock. Here, we investigate how the plasma and fields behave at this boundary and where it can be found. The main result is that the infant bow shock occurs at intermediate activity and intermediate distances to the comet. Most plasma parameters behave as expected; however, some inconsistencies indicate that the boundary is non-stationary.
Audrey Schillings, Herbert Gunell, Hans Nilsson, Alexandre De Spiegeleer, Yusuke Ebihara, Lars G. Westerberg, Masatoshi Yamauchi, and Rikard Slapak
Ann. Geophys., 38, 645–656, https://doi.org/10.5194/angeo-38-645-2020, https://doi.org/10.5194/angeo-38-645-2020, 2020
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The Earth's atmosphere is constantly losing molecules and charged particles, amongst them oxygen ions or O+. Quantifying this loss provides information about the evolution of the atmosphere on geological timescales. In this study, we investigate the final destination of O+ observed with Cluster satellites in a high-altitude magnetospheric region (plasma mantle) by tracing the particles forward in time using simulations. We find that approximately 98 % of O+ escapes the Earth's magnetosphere.
H. Gunell, L. Andersson, J. De Keyser, and I. Mann
Ann. Geophys., 33, 1331–1342, https://doi.org/10.5194/angeo-33-1331-2015, https://doi.org/10.5194/angeo-33-1331-2015, 2015
Short summary
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In a simulation study of the downward current region of the aurora, i.e. where electrons are accelerated upward, double layers are seen to form at low altitude and move upward until they are disrupted at altitudes of ten thousand kilometres or thereabouts. When one double layer is disrupted a new one forms below, and the process repeats itself. The repeated demise and reformation allows ions to flow upward without passing through the double layers that otherwise would have kept them down.
H. Gunell, L. Andersson, J. De Keyser, and I. Mann
Ann. Geophys., 33, 279–293, https://doi.org/10.5194/angeo-33-279-2015, https://doi.org/10.5194/angeo-33-279-2015, 2015
Short summary
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In this paper, we simulate the plasma on a magnetic field line above the aurora. Initially, about half of the acceleration voltage is concentrated in a thin double layer at a few thousand km altitude. When the voltage is lowered, electrons trapped between the double layer and the magnetic mirror are released. In the process we see formation of electron beams and phase space holes. A temporary reversal of the polarity of the double layer is also seen as well as hysteresis effects in its position.
H. Gunell, G. Stenberg Wieser, M. Mella, R. Maggiolo, H. Nilsson, F. Darrouzet, M. Hamrin, T. Karlsson, N. Brenning, J. De Keyser, M. André, and I. Dandouras
Ann. Geophys., 32, 991–1009, https://doi.org/10.5194/angeo-32-991-2014, https://doi.org/10.5194/angeo-32-991-2014, 2014
H. Gunell, J. De Keyser, E. Gamby, and I. Mann
Ann. Geophys., 31, 1227–1240, https://doi.org/10.5194/angeo-31-1227-2013, https://doi.org/10.5194/angeo-31-1227-2013, 2013
Ariel Tello Fallau, Charlotte Goetz, Cyril Simon Wedlund, Martin Volwerk, and Anja Moeslinger
Ann. Geophys., 41, 569–587, https://doi.org/10.5194/angeo-41-569-2023, https://doi.org/10.5194/angeo-41-569-2023, 2023
Short summary
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The plasma environment of comet 67P provides a unique laboratory to study plasma phenomena in the solar system. Previous studies have reported the existence of mirror modes at 67P but no further systematic investigation has so far been done. This study aims to learn more about these waves. We investigate the magnetic field measured by Rosetta and find 565 mirror mode signatures. The detected mirror modes are likely generated upstream of the observation and have been modified by the plasma.
Martin Volwerk, Cyril Simon Wedlund, David Mautner, Sebastián Rojas Mata, Gabriella Stenberg Wieser, Yoshifumi Futaana, Christian Mazelle, Diana Rojas-Castillo, César Bertucci, and Magda Delva
Ann. Geophys., 41, 389–408, https://doi.org/10.5194/angeo-41-389-2023, https://doi.org/10.5194/angeo-41-389-2023, 2023
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Freshly created ions in solar wind start gyrating around the interplanetary magnetic field. When they cross the bow shock, they get an extra kick, and this increases the plasma pressure against the magnetic pressure. This leads to the creation of so-called mirror modes, regions where the magnetic field decreases in strength and the plasma density increases. These structures help in exploring how energy is transferred from the ions to the magnetic field and where around Venus this is happening.
Cyril Simon Wedlund, Martin Volwerk, Christian Mazelle, Sebastián Rojas Mata, Gabriella Stenberg Wieser, Yoshifumi Futaana, Jasper Halekas, Diana Rojas-Castillo, César Bertucci, and Jared Espley
Ann. Geophys., 41, 225–251, https://doi.org/10.5194/angeo-41-225-2023, https://doi.org/10.5194/angeo-41-225-2023, 2023
Short summary
Short summary
Mirror modes are magnetic bottles found in the space plasma environment of planets contributing to the energy exchange with the solar wind. We use magnetic field measurements from the NASA Mars Atmosphere and Volatile EvolutioN mission to detect them around Mars and show how they evolve in time and space. The structures concentrate in two regions: one behind the bow shock and the other closer to the planet. They compete with other wave modes depending on the solar flux and heliocentric distance.
Tomas Karlsson, Henriette Trollvik, Savvas Raptis, Hans Nilsson, and Hadi Madanian
Ann. Geophys., 40, 687–699, https://doi.org/10.5194/angeo-40-687-2022, https://doi.org/10.5194/angeo-40-687-2022, 2022
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Magnetic holes are curious localized dropouts of magnetic field strength in the solar wind (the flow of ionized gas continuously streaming out from the sun). In this paper we show that these magnetic holes can cross the bow shock (where the solar wind brake down to subsonic velocity) and enter the region close to Earth’s magnetosphere. These structures may therefore represent a new type of non-uniform solar wind–magnetosphere interaction.
Katharina Ostaszewski, Karl-Heinz Glassmeier, Charlotte Goetz, Philip Heinisch, Pierre Henri, Sang A. Park, Hendrik Ranocha, Ingo Richter, Martin Rubin, and Bruce Tsurutani
Ann. Geophys., 39, 721–742, https://doi.org/10.5194/angeo-39-721-2021, https://doi.org/10.5194/angeo-39-721-2021, 2021
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Plasma waves are an integral part of cometary physics, as they facilitate the transfer of energy and momentum. From intermediate to strong activity, nonlinear asymmetric plasma and magnetic field enhancements dominate the inner coma of 67P/CG. We present a statistical survey of these structures from December 2014 to June 2016, facilitated by Rosetta's unprecedented long mission duration. Using a 1D MHD model, we show they can be described as a combination of nonlinear and dissipative effects.
Charlotte Goetz, Herbert Gunell, Fredrik Johansson, Kristie LLera, Hans Nilsson, Karl-Heinz Glassmeier, and Matthew G. G. T. Taylor
Ann. Geophys., 39, 379–396, https://doi.org/10.5194/angeo-39-379-2021, https://doi.org/10.5194/angeo-39-379-2021, 2021
Short summary
Short summary
Boundaries in the plasma around comet 67P separate regions with different properties. Many have been identified, including a new boundary called an infant bow shock. Here, we investigate how the plasma and fields behave at this boundary and where it can be found. The main result is that the infant bow shock occurs at intermediate activity and intermediate distances to the comet. Most plasma parameters behave as expected; however, some inconsistencies indicate that the boundary is non-stationary.
Martin Volwerk, David Mautner, Cyril Simon Wedlund, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Schmid, Diana Rojas-Castillo, Owen W. Roberts, and Ali Varsani
Ann. Geophys., 39, 239–253, https://doi.org/10.5194/angeo-39-239-2021, https://doi.org/10.5194/angeo-39-239-2021, 2021
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The magnetic field in the solar wind is not constant but varies in direction and strength. One of these variations shows a strong local reduction of the magnetic field strength and is called a magnetic hole. These holes are usually an indication that there is, or has been, a temperature difference in the plasma of the solar wind, with the temperature along the magnetic field lower than perpendicular. The MMS spacecraft data have been used to study the characteristics of these holes near Earth.
Audrey Schillings, Herbert Gunell, Hans Nilsson, Alexandre De Spiegeleer, Yusuke Ebihara, Lars G. Westerberg, Masatoshi Yamauchi, and Rikard Slapak
Ann. Geophys., 38, 645–656, https://doi.org/10.5194/angeo-38-645-2020, https://doi.org/10.5194/angeo-38-645-2020, 2020
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The Earth's atmosphere is constantly losing molecules and charged particles, amongst them oxygen ions or O+. Quantifying this loss provides information about the evolution of the atmosphere on geological timescales. In this study, we investigate the final destination of O+ observed with Cluster satellites in a high-altitude magnetospheric region (plasma mantle) by tracing the particles forward in time using simulations. We find that approximately 98 % of O+ escapes the Earth's magnetosphere.
Martin Volwerk, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Heyner, and Brian Anderson
Ann. Geophys., 38, 51–60, https://doi.org/10.5194/angeo-38-51-2020, https://doi.org/10.5194/angeo-38-51-2020, 2020
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The magnetic field that is carried by the solar wind slowly decreases in strength as it moves further from the Sun. However, there are sometimes localized decreases in the magnetic field strength, called magnetic holes. These are small structures where the magnetic field strength decreases to less than 50 % of the surroundings and the plasma density increases. This paper presents a statistical study of the behaviour of these holes between Mercury and Venus using MESSENGER data.
Audrey Schillings, Hans Nilsson, Rikard Slapak, Masatoshi Yamauchi, and Lars-Göran Westerberg
Ann. Geophys., 35, 1341–1352, https://doi.org/10.5194/angeo-35-1341-2017, https://doi.org/10.5194/angeo-35-1341-2017, 2017
Short summary
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The Earth's atmosphere is constantly losing ions and in particular oxygen ions. This phenomenon is important to understand the atmospheric evolution on a large timescale. In this study, the O+ outflow is estimated during six extreme geomagnetic storms using the European Cluster mission data. These estimations are compared with average magnetospheric conditions and show that during those six extreme storms, the O+ outflow is approximately 2 orders of magnitude higher.
Rikard Slapak, Maria Hamrin, Timo Pitkänen, Masatoshi Yamauchi, Hans Nilsson, Tomas Karlsson, and Audrey Schillings
Ann. Geophys., 35, 869–877, https://doi.org/10.5194/angeo-35-869-2017, https://doi.org/10.5194/angeo-35-869-2017, 2017
Short summary
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The ion total transports in the near-Earth plasma sheet have been investigated and quantified. Specifically, the net O+ transport is about 1024 s−1 in the earthward direction, which is 1 order of magnitude smaller than the typical O+ ionospheric outflows, strongly indicating that most outflow will eventually escape, leading to significant atmospheric loss. The study also shows that low-velocity flows (< 100 km s−1) dominate the mass transport in the near-Earth plasma sheet.
Rikard Slapak, Audrey Schillings, Hans Nilsson, Masatoshi Yamauchi, Lars-Göran Westerberg, and Iannis Dandouras
Ann. Geophys., 35, 721–731, https://doi.org/10.5194/angeo-35-721-2017, https://doi.org/10.5194/angeo-35-721-2017, 2017
Short summary
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In this study, we have used Cluster satellite data to quantify the ionospheric oxygen ion (O+) escape into the solar wind and its dependence on geomagnetic activity. During times of high activity, the escape may be 2 orders of magnitude higher than under quiet conditions, strongly suggesting that the escape rate was much higher when the Sun was young. The results are important for future studies regarding atmospheric loss over geological timescales.
Ingo Richter, Hans-Ulrich Auster, Gerhard Berghofer, Chris Carr, Emanuele Cupido, Karl-Heinz Fornaçon, Charlotte Goetz, Philip Heinisch, Christoph Koenders, Bernd Stoll, Bruce T. Tsurutani, Claire Vallat, Martin Volwerk, and Karl-Heinz Glassmeier
Ann. Geophys., 34, 609–622, https://doi.org/10.5194/angeo-34-609-2016, https://doi.org/10.5194/angeo-34-609-2016, 2016
Short summary
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We have analysed the magnetic field measurements performed on the ROSETTA orbiter and the lander PHILAE during PHILAE's descent to comet 67P/Churyumov-Gerasimenko on 12 November 2014. We observed a new type of low-frequency wave with amplitudes of ~ 3 nT, frequencies of 20–50 mHz, wavelengths of ~ 300 km, and propagation velocities of ~ 6 km s−1. The waves are generated in a ~ 100 km region around the comet a show a highly correlated behaviour, which could only be determined by two-point observations.
M. Volwerk, I. Richter, B. Tsurutani, C. Götz, K. Altwegg, T. Broiles, J. Burch, C. Carr, E. Cupido, M. Delva, M. Dósa, N. J. T. Edberg, A. Eriksson, P. Henri, C. Koenders, J.-P. Lebreton, K. E. Mandt, H. Nilsson, A. Opitz, M. Rubin, K. Schwingenschuh, G. Stenberg Wieser, K. Szegö, C. Vallat, X. Vallieres, and K.-H. Glassmeier
Ann. Geophys., 34, 1–15, https://doi.org/10.5194/angeo-34-1-2016, https://doi.org/10.5194/angeo-34-1-2016, 2016
Short summary
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The solar wind magnetic field drapes around the active nucleus of comet 67P/CG, creating a magnetosphere. The solar wind density increases and with that the pressure, which compresses the magnetosphere, increasing the magnetic field strength near Rosetta. The higher solar wind density also creates more ionization through collisions with the gas from the comet. The new ions are picked-up by the magnetic field and generate mirror-mode waves, creating low-field high-density "bottles" near 67P/CG.
H. Gunell, L. Andersson, J. De Keyser, and I. Mann
Ann. Geophys., 33, 1331–1342, https://doi.org/10.5194/angeo-33-1331-2015, https://doi.org/10.5194/angeo-33-1331-2015, 2015
Short summary
Short summary
In a simulation study of the downward current region of the aurora, i.e. where electrons are accelerated upward, double layers are seen to form at low altitude and move upward until they are disrupted at altitudes of ten thousand kilometres or thereabouts. When one double layer is disrupted a new one forms below, and the process repeats itself. The repeated demise and reformation allows ions to flow upward without passing through the double layers that otherwise would have kept them down.
I. Richter, C. Koenders, H.-U. Auster, D. Frühauff, C. Götz, P. Heinisch, C. Perschke, U. Motschmann, B. Stoll, K. Altwegg, J. Burch, C. Carr, E. Cupido, A. Eriksson, P. Henri, R. Goldstein, J.-P. Lebreton, P. Mokashi, Z. Nemeth, H. Nilsson, M. Rubin, K. Szegö, B. T. Tsurutani, C. Vallat, M. Volwerk, and K.-H. Glassmeier
Ann. Geophys., 33, 1031–1036, https://doi.org/10.5194/angeo-33-1031-2015, https://doi.org/10.5194/angeo-33-1031-2015, 2015
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We present a first report on magnetic field measurements made in the coma of comet 67P/C-G in its low-activity state. The plasma environment is dominated by quasi-coherent, large-amplitude, compressional magnetic field oscillations around 40mHz, differing from the observations at strongly active comets where waves at the cometary ion gyro-frequencies are the main feature. We propose a cross-field current instability associated with the newborn cometary ions as a possible source mechanism.
R. Slapak, H. Nilsson, L. G. Westerberg, and R. Larsson
Ann. Geophys., 33, 301–307, https://doi.org/10.5194/angeo-33-301-2015, https://doi.org/10.5194/angeo-33-301-2015, 2015
H. Gunell, L. Andersson, J. De Keyser, and I. Mann
Ann. Geophys., 33, 279–293, https://doi.org/10.5194/angeo-33-279-2015, https://doi.org/10.5194/angeo-33-279-2015, 2015
Short summary
Short summary
In this paper, we simulate the plasma on a magnetic field line above the aurora. Initially, about half of the acceleration voltage is concentrated in a thin double layer at a few thousand km altitude. When the voltage is lowered, electrons trapped between the double layer and the magnetic mirror are released. In the process we see formation of electron beams and phase space holes. A temporary reversal of the polarity of the double layer is also seen as well as hysteresis effects in its position.
T. Pitkänen, M. Hamrin, P. Norqvist, T. Karlsson, H. Nilsson, A. Kullen, S. M. Imber, and S. E. Milan
Ann. Geophys., 33, 245–255, https://doi.org/10.5194/angeo-33-245-2015, https://doi.org/10.5194/angeo-33-245-2015, 2015
Short summary
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An azimuthal velocity shear with a reversal within an earthward magnetotail fast flow is studied using Cluster observations. In addition, ionospheric SuperDARN data and different magnetospheric models (T96 and TF04) are utilized when interpreting the Cluster observations. Untwisting of twisted tail B field lines is a good candidate to explain the observations.
I. A. Barghouthi, H. Nilsson, and S. H. Ghithan
Ann. Geophys., 32, 1043–1057, https://doi.org/10.5194/angeo-32-1043-2014, https://doi.org/10.5194/angeo-32-1043-2014, 2014
H. Gunell, G. Stenberg Wieser, M. Mella, R. Maggiolo, H. Nilsson, F. Darrouzet, M. Hamrin, T. Karlsson, N. Brenning, J. De Keyser, M. André, and I. Dandouras
Ann. Geophys., 32, 991–1009, https://doi.org/10.5194/angeo-32-991-2014, https://doi.org/10.5194/angeo-32-991-2014, 2014
K. Axelsson, T. Sergienko, H. Nilsson, U. Brändström, K. Asamura, and T. Sakanoi
Ann. Geophys., 32, 499–506, https://doi.org/10.5194/angeo-32-499-2014, https://doi.org/10.5194/angeo-32-499-2014, 2014
H. Gunell, J. De Keyser, E. Gamby, and I. Mann
Ann. Geophys., 31, 1227–1240, https://doi.org/10.5194/angeo-31-1227-2013, https://doi.org/10.5194/angeo-31-1227-2013, 2013
R. Slapak, H. Nilsson, and L. G. Westerberg
Ann. Geophys., 31, 1005–1010, https://doi.org/10.5194/angeo-31-1005-2013, https://doi.org/10.5194/angeo-31-1005-2013, 2013
S. Kirkwood, E. Belova, P. Dalin, M. Mihalikova, D. Mikhaylova, D. Murtagh, H. Nilsson, K. Satheesan, J. Urban, and I. Wolf
Ann. Geophys., 31, 333–347, https://doi.org/10.5194/angeo-31-333-2013, https://doi.org/10.5194/angeo-31-333-2013, 2013
I. Mann and M. Hamrin
Ann. Geophys., 31, 39–44, https://doi.org/10.5194/angeo-31-39-2013, https://doi.org/10.5194/angeo-31-39-2013, 2013
K. Axelsson, T. Sergienko, H. Nilsson, U. Brändström, Y. Ebihara, K. Asamura, and M. Hirahara
Ann. Geophys., 30, 1693–1701, https://doi.org/10.5194/angeo-30-1693-2012, https://doi.org/10.5194/angeo-30-1693-2012, 2012
Cited articles
Acton, C. H.: Ancillary data services of NASA's Navigation and Ancillary
Information Facility, Planet. Space Sci., 44, 65–70,
https://doi.org/10.1016/0032-0633(95)00107-7, 1996. a
André, M., Odelstad, E., Graham, D. B., Eriksson, A. I., Karlsson, T.,
Stenberg Wieser, G., Vigren, E., Norgren, C., Johansson, F. L.,
Henri, P., Rubin, M., and Richter, I.: Lower hybrid waves at comet
67P/Churyumov-Gerasimenko, Mon. Not. R. Astron.
Soc., 469, 29–38, https://doi.org/10.1093/mnras/stx868, 2017. a
Berčič, L., Behar, E., Nilsson, H., Nicolaou, G., Stenberg Wieser,
G., Wieser, M., and Goetz, C.: Cometary ion dynamics observed in the close
vicinity of comet 67P/Churyumov-Gerasimenko during the intermediate
activity period, Astron. Astrophys., 613, A57,
https://doi.org/10.1051/0004-6361/201732082, 2018. a
Bergman, S., Stenberg Wieser, G., Wieser, M., Johansson, F. L., and Eriksson,
A.: The Influence of Spacecraft Charging on Low‐Energy Ion Measurements
Made by RPC-ICA on Rosetta, J. Geophys. Res.-Space, 125,
e2019JA027478, https://doi.org/10.1029/2019JA027478, 2020a. a
Bergman, S., Stenberg Wieser, G., Wieser, M., Johansson, F. L., and Eriksson,
A.: The Influence of Varying Spacecraft Potentials and Debye Lengths on In
Situ Low-Energy Ion Measurements, J. Geophys. Res.-Space, 125,
e2020JA027870, https://doi.org/10.1029/2020JA027870, 2020b. a
Biver, N., Bockelée-Morvan, D., Hofstadter, M., Lellouch, E., Choukroun,
M., Gulkis, S., Crovisier., J., Schloerb, F. P., Rezac, L., von Allmen, P.,
Lee, S., Leyrat, C., Ip, W. H., Hartogh, P., Encrenaz, P., Beaudin, G., and
the MIRO Team: Long-term monitoring of the outgassing and composition of
comet 67P/Churyumov-Gerasimenko with the Rosetta/MIRO instrument,
Astron. Astrophys., 630, A19, https://doi.org/10.1051/0004-6361/201834960, 2019. a, b
Breuillard, H., Henri, P., Bucciantini, L., Volwerk, M., Karlsson, T.,
Eriksson, A., Johansson, F., Odelstad, E., Richter, I., Goetz, C.,
Vallières, X., and Hajra, R.: The properties of the singing comet waves in
the 67P/Churyumov-Gerasimenko plasma environment as observed by the
Rosetta mission, Astron. Astrophys.,
https://doi.org/10.1051/0004-6361/201834876, 2019. a
Carr, C., Cupido, E., Lee, C. G. Y., Balogh, A., Beek, T., Burch,
J. L., Dunford, C. N., Eriksson, A. I., Gill, R., Glassmeier, K. H.,
Goldstein, R., Lagoutte, D., Lundin, R., Lundin, K., Lybekk, B.,
Michau, J. L., Musmann, G., Nilsson, H., Pollock, C., Richter, I.,
and Trotignon, J. G.: RPC: The Rosetta Plasma Consortium, Space
Sci. Rev., 128, 629–647, https://doi.org/10.1007/s11214-006-9136-4, 2007. a
Engelhardt, I. A. D., Eriksson, A. I., Vigren, E., Valliéres, X., Rubin,
M., Gilet, N., and Henri, P.: Cold electrons at comet
67P/Churyumov-Gerasimenko, Astron. Astrophys., 616, A51,
https://doi.org/10.1051/0004-6361/201833251, 2018. a
Eriksson, A. I., Boström, R., Gill, R., Åhlén, L., Jansson, S.-E.,
Wahlund, J.-E., André, M., Mälkki, A., Holtet, J. A., Lybekk, B.,
Pedersen, A., and Blomberg, L. G.: RPC-LAP: The Rosetta Langmuir Probe
Instrument, Space Sci. Rev., 128, 729–744,
https://doi.org/10.1007/s11214-006-9003-3, 2007. a
Eriksson, A. I., Engelhardt, I. A. D., André, M., Boström, R., Edberg,
N. J. T., Johansson, F. L., Odelstad, E., Vigren, E., Wahlund, J.-E., Henri,
P., Lebreton, J.-P., Miloch, W. J., Paulsson, J. J. P., Wedlund, C. S., Yang,
L., Karlsson, T., Broiles, T., Mandt, K., Carr, C. M., Galand, M., Nilsson,
H., and Norberg, C.: Cold and warm electrons at comet
67P/Churyumov-Gerasimenko, Astron. Astrophys., 605, A15,
https://doi.org/10.1051/0004-6361/201630159, 2017. a
European Space Agency: Planetary Science Archive, available at: https://archives.esac.esa.int/psa, last access: 21 December 2020. a
Gilet, N., Henri, P., Wattieaux, G., Cilibrasi, M., and Béghin, C.:
Electrostatic Potential Radiated by a Pulsating Charge in a Two-Electron
Temperature Plasma, Radio Sci., 52, 1432–1448,
https://doi.org/10.1002/2017RS006294, 2017. a
Glassmeier, K.-H., Boehnhardt, H., Koschny, D., Kührt, E., and Richter, I.:
The Rosetta Mission: Flying Towards the Origin of the Solar System, Space
Sci. Rev., 128, 1–21, https://doi.org/10.1007/s11214-006-9140-8,
2007a. a
Glassmeier, K.-H., Richter, I., Diedrich, A., Musmann, G., Auster, U.,
Motschmann, U., Balogh, A., Carr, C., Cupido, E., Coates, A.,
Rother, M., Schwingenschuh, K., Szegö, K., and Tsurutani, B.:
RPC-MAG The Fluxgate Magnetometer in the ROSETTA Plasma Consortium, Space
Sci. Rev., 128, 649–670, https://doi.org/10.1007/s11214-006-9114-x,
2007b. a
Goetz, C., Koenders, C., Hansen, K. C., Burch, J., Carr, C., Eriksson, A.,
Frühauff, D., Güttler, C., Henri, P., Nilsson, H., Richter, I.,
Rubin, M., Sierks, H., Tsurutani, B., Volwerk, M., and Glassmeier, K. H.:
Structure and evolution of the diamagnetic cavity at comet
67P/Churyumov-Gerasimenko, Mon. Not. R. Astron.
Soc., 462, S459, https://doi.org/10.1093/mnras/stw3148, 2016a. a, b, c, d
Goetz, C., Koenders, C., Richter, I., Altwegg, K., Burch, J., Carr, C.,
Cupido, E., Eriksson, A., Güttler, C., Henri, P., Mokashi, P.,
Nemeth, Z., Nilsson, H., Rubin, M., Sierks, H., Tsurutani, B.,
Vallat, C., Volwerk, M., and Glassmeier, K.-H.: First detection of a
diamagnetic cavity at comet 67P/Churyumov-Gerasimenko, Astron.
Astrophys., 588, A24, https://doi.org/10.1051/0004-6361/201527728,
2016b. a
Götz, C., Gunell, H., Volwerk, M., Beth, A., Eriksson, A.,
Galand, M., Henri, P., Nilsson, H., Wedlund, C. S., Alho, M.,
Andersson, L., Andre, N., De Keyser, J., Deca, J., Ge, Y.,
Glaßmeier, K.-H., Hajra, R., Karlsson, T., Kasahara, S.,
Kolmasova, I., Lera, K., Madanian, H., Mann, I., Mazelle, C.,
Odelstad, E., Plaschke, F., Rubin, M., Sanchez-Cano, B., Snodgrass,
C., and Vigren, E.: Cometary Plasma Science – A White Paper in response to
the Voyage 2050 Call by the European Space Agency,
arXiv [preprint], https://arxiv.org/pdf/1908.00377.pdf, 2019. a
Goetz, C., Plaschke, F., and Taylor, M. G. G. T.: Singing Comet Waves in a
Solar Wind Convective Electric Field Frame, Geophys. Res. Lett., 47,
e2020GL087418, https://doi.org/10.1029/2020GL087418, 2020. a
Gunell, H. and Skiff, F.: Weakly damped acoustic-like ion waves in plasmas with
non-Maxwellian ion distributions, Phys. Plasmas, 8, 3550–3557,
https://doi.org/10.1063/1.1386428, 2001. a, b
Gunell, H. and Skiff, F.: Electrostatic fluctuations in plasmas with
distribution functions described by simple pole expansions, Phys.
Plasmas, 9, 2585–2592, https://doi.org/10.1063/1.1476666, 2002. a, b, c
Gunell, H., Goetz, C., Eriksson, A., Nilsson, H., Simon Wedlund, C., Henri,
P., Maggiolo, R., Hamrin, M., De Keyser, J., Rubin, M., Stenberg Wieser,
G., Cessateur, G., Dhooghe, F., and Gibbons, A.: Plasma waves confined to the
diamagnetic cavity of comet 67P/Churyumov-Gerasimenko, Mon. Not.
R. Astron. Soc., 469, S84, https://doi.org/10.1093/mnras/stx1134,
2017a. a, b, c, d
Gunell, H., Nilsson, H., Hamrin, M., Eriksson, A., Odelstad, E., Maggiolo, R.,
Henri, P., Vallières, X., Altwegg, K., Tzou, C.-Y., Rubin, M.,
Glassmeier, K.-H., Stenberg Wieser, G., Simon Wedlund, C., De Keyser,
J., Dhooghe, F., Cessateur, G., and Gibbons, A.: Ion acoustic waves at comet
67P/Churyumov-Gerasimenko – Observations and computations, Astron. Astrophys., 600, A3, https://doi.org/10.1051/0004-6361/201629801,
2017b. a, b, c, d, e, f, g
Gunell, H., Goetz, C., Simon Wedlund, C., Lindkvist, J., Hamrin, M., Nilsson,
H., Lera, K., Eriksson, A., and Holmström, M.: The infant bow shock: a
new frontier at a weak activity comet, Astron. Astrophys., 619, L2,
https://doi.org/10.1051/0004-6361/201834225, 2018. a
Gunell, H., Lindkvist, J., Goetz, C., Nilsson, H., and Hamrin, M.: Polarisation
of a small-scale cometary plasma environment: Particle-in-cell modelling of
comet 67P/Churyumov-Gerasimenko, Astron. Astrophys., 631, A174,
https://doi.org/10.1051/0004-6361/201936004, 2019. a
Gunell, H., Goetz, C., Odelstad, E., Beth, A., Hamrin, M., Henri, P.,
Johansson, F. L., Nilsson, H., and Wieser, G. S.: Dataset for Waves during
Rosetta's close flyby of comet 67P, zenodo, https://doi.org/10.5281/zenodo.3973232, 2020. a
Johansson, F. L., Eriksson, A. I., Gilet, N., Henri, P., Wattieaux, G., Taylor,
M. G. G. T., Imhof, C., and Cipriani, F.: A charging model for the Rosetta
spacecraft, Astron. Astrophys., 642, A43,
https://doi.org/10.1051/0004-6361/202038592, 2020. a
Karlsson, T., Eriksson, A. I., Odelstad, E., André, M., Dickeli, G.,
Kullen, A., Lindqvist, P.-A., Nilsson, H., and Richter, I.: Rosetta
measurements of lower hybrid frequency range electric field oscillations in
the plasma environment of comet 67P, Geophys. Res. Lett., 44, 1641–1651,
https://doi.org/10.1002/2016GL072419, 2017. a
Kawai, Y., Hollenstein, C., and Guyot, M.: Ion acoustic turbulence in a
large-volume plasma, Phys. Fluids, 21, 970–974, https://doi.org/10.1063/1.862340,
1978. a, b
Koenders, C., Goetz, C., Richter, I., Motschmann, U., and Glassmeier, K.-H.:
Magnetic field pile-up and draping at intermediately active comets: results
from comet 67P/Churyumov-Gerasimenko at 2.0 AU, Mon. Not.
R. Astron. Soc., 462, 235–241, https://doi.org/10.1093/mnras/stw2480,
2016. a, b, c, d, e, f
Löfgren, T. and Gunell, H.: Flexible Simple-Pole Expansion of Distribution
Functions, Phys. Plasmas, 4, 3469–3476, https://doi.org/10.1063/1.872243, 1997. a, b
Madsen, B., Simon Wedlund, C., Eriksson, A., Goetz, C., Karlsson, T., Gunell,
H., Spicher, A., Henri, P., Vallières, X., and Miloch, W.: Extremely
low-frequency waves inside the diamagnetic cavity of comet
67P/Churyumov-Gerasimenko, Geophys. Res. Lett., 45, 3854–3864,
https://doi.org/10.1029/2017GL076415, 2018. a
Glassmeier, K.-H., and Motschmann, U.: Modified ion-Weibel instability as a possible source of wave activity at Comet 67P/Churyumov-Gerasimenko, Ann. Geophys., 34, 691–707, https://doi.org/10.5194/angeo-34-691-2016, 2016. a
Michelsen, P., Pecseli, H. L., Juul Rasmussen, J., and Schrittwieser, R.: The
current-driven, ion-acoustic instability in a collisionless plasma, Plasma
Phys., 21, 61–73, https://doi.org/10.1088/0032-1028/21/1/005, 1979. a
Mott-Smith, H. M. and Langmuir, I.: The Theory of Collectors in Gaseous
Discharges, Phys. Rev., 28, 727–763, https://doi.org/10.1103/PhysRev.28.727,
1926. a
Nilsson, H., Lundin, R., Lundin, K., Barabash, S., Borg, H., Norberg, O.,
Fedorov, A., Sauvaud, J.-A., Koskinen, H., Kallio, E., Riihelä, P., and
Burch, J. L.: RPC-ICA: The Ion Composition Analyzer of the Rosetta
Plasma Consortium, Space Sci. Rev., 128, 671–695,
https://doi.org/10.1007/s11214-006-9031-z, 2007. a
Odelstad, E., Eriksson, A. I., Johansson, F. L., Vigren, E., Henri, P.,
Gilet, N., Heritier, K. L., Vallières, X., Rubin, M., and
André, M.: Ion Velocity and Electron Temperature Inside and Around the
Diamagnetic Cavity of Comet 67P, J. Geophys. Res.-Space, 123,
5870–5893, https://doi.org/10.1029/2018JA025542, 2018. a, b, c, d
Oya, H., Morioka, A., Miyake, W., Smith, E. J., and Tsurutani, B. T.: Discovery
of cometary kilometric radiations and plasma waves at comet Halley, Nature,
321, 307–310, https://doi.org/10.1038/321307a0, 1986. a
Richter, I., Koenders, C., Auster, H.-U., Frühauff, D., Götz, C., Heinisch, P., Perschke, C., Motschmann, U., Stoll, B., Altwegg, K., Burch, J., Carr, C., Cupido, E., Eriksson, A., Henri, P., Goldstein, R., Lebreton, J.-P., Mokashi, P., Nemeth, Z., Nilsson, H., Rubin, M., Szegö, K., Tsurutani, B. T., Vallat, C., Volwerk, M., and Glassmeier, K.-H.: Observation of a new type of low-frequency waves at comet 67P/Churyumov-Gerasimenko, Ann. Geophys., 33, 1031–1036, https://doi.org/10.5194/angeo-33-1031-2015, 2015. a
Richter, I., Auster, H.-U., Berghofer, G., Carr, C., Cupido, E., Fornaçon, K.-H., Goetz, C., Heinisch, P., Koenders, C., Stoll, B., Tsurutani, B. T., Vallat, C., Volwerk, M., and Glassmeier, K.-H.: Two-point observations of low-frequency waves at 67P/Churyumov-Gerasimenko during the descent of PHILAE: comparison of RPCMAG and ROMAP, Ann. Geophys., 34, 609–622, https://doi.org/10.5194/angeo-34-609-2016, 2016. a
Sato, N., Popa, G., Märk, E., Mravlag, E., and Schrittwieser, R.:
Instability as a source for traveling ion waves, Phys. Fluids, 19,
70–73, https://doi.org/10.1063/1.861330, 1976. a
Scarf, F.: Plasma wave observations at Comets Giacobini-Zinner and
Halley, Geophysical Monograph
Series, 53, American Geophysical Union, Washington, DC, USA,
https://doi.org/10.1029/GM053p0031, 1989. a
Scarf, F. L., Coroniti, F. V., Kennel, C. F., Sanderson, T. R., Wenzel,
K. P., Hynds, R. J., Smith, E. J., Bame, S. J., and Zwickl, R. D.:
ICE plasma wave measurements in the ion pick-up region of comet Halley,
Geophys. Res. Lett., 13, 857–860, https://doi.org/10.1029/GL013i008p00857,
1986a. a
Scarf, F. L., Ferdinand, V., Coroniti, V., Kennel, C. F., Gurnett, D. A., Ip,
W.-H., and Smith, E. J.: Plasma wave observations at comet
Giacobini-Zinner, Science, 232, 377–381,
https://doi.org/10.1126/science.232.4748.377, 1986b. a
Scarf, F. L., Ferdinand, V., Coroniti, V., Kennel, C. F., Gurnett, D. A., Ip,
W.-H., and Smith, E. J.: Plasma wave observations at comet
Giacobini-Zinner, Science, 232, 377–381,
https://doi.org/10.1126/science.232.4748.377, 1986c. a
Stenberg Wieser, G., Odelstad, E., Nilsson, H., Wieser, M., Goetz, C.,
Karlsson, T., Kalla, L., André, M., Eriksson, A. I., Nicolaou, G., Simon
Wedlund, C., Richter, I., and Gunell, H.: Investigating short time-scale
variations in cometary ions around comet 67P, Mon. Not. R.
Astron. Soc., 469, 522–534, https://doi.org/10.1093/mnras/stx2133, 2017.
a
Stringer, T. E.: Electrostatic instabilities in current-carrying and
counterstreaming plasmas, J. Nucl. Energy, 6, 267–279,
https://doi.org/10.1088/0368-3281/6/3/305, 1964. a
Swift, J. D. and Schwar, M. J. R.: Electrical Probes for Plasma Diagnostics,
Iliffe Books, London, UK, 1970. a
Tjulin, A. and André, M.: The dielectric tensor of simple-pole distribution
functions in magnetized plasmas, Phys. Plasmas, 9, 1775–1784,
https://doi.org/10.1063/1.1463410, 2002. a, b
Tjulin, A., Eriksson, A. I., and André, M.: Physical interpretation of the
Padé approximation of the plasma dispersion function, J. Plasma
Phys., 64, 287–296, https://doi.org/10.1017/S0022377800008606, 2000. a, b
Torvén, S., Gunell, H., and Brenning, N.: A high frequency probe for
absolute measurements of electric fields in plasmas, J. Phys. D
Appl. Phys., 28, 595–599, https://doi.org/10.1088/0022-3727/28/3/023, 1995. a
Trotignon, J. G., Michau, J. L., Lagoutte, D., Chabassière, M., Chalumeau,
G., Colin, F., Décréau, P. M. E., Geiswiller, J., Gille, P., Grard,
R., Hachemi, T., Hamelin, M., Eriksson, A., Laakso, H., Lebreton, J. P.,
Mazelle, C., Randriamboarison, O., Schmidt, W., Smit, A., Telljohann, U., and
Zamora, P.: RPC-MIP: the Mutual Impedance Probe of the Rosetta
Plasma Consortium, Space Sci. Rev., 128, 713–728,
https://doi.org/10.1007/s11214-006-9005-1, 2007. a
Vigren, E. and Eriksson, A. I.: A 1D Model of Radial Ion Motion Interrupted
by Ion–Neutral Interactions in a Cometary Coma, Astron. J.,
153, 150, https://doi.org/10.3847/1538-3881/aa6006, 2017. a
Wattieaux, G., Henri, P., Gilet, N., Vallières, X., and Deca, J.: Plasma
characterization at comet 67P between 2 and 4 AU from the Sun with the
RPC-MIP instrument, Astron. Astrophys., 638, A124,
https://doi.org/10.1051/0004-6361/202037571, 2020. a, b
Welch, P. D.: The Use of Fast Fourier Transform for the Estimation of Power
Spectra: A Method Based on Time Averaging Over Short, Modified Periodograms,
IEEE T.
Acust. Speech,
15, 70–73, 1967. a
Short summary
When the magnetised solar wind meets the plasma surrounding a comet, the magnetic field is enhanced in front of the comet, and the field lines are draped around it. This happens because electric currents are induced in the plasma. When these currents flow through the plasma, they can generate waves. In this article we present observations of ion acoustic waves, which is a kind of sound wave in the plasma, detected by instruments on the Rosetta spacecraft near comet 67P/Churyumov–Gerasimenko.
When the magnetised solar wind meets the plasma surrounding a comet, the magnetic field is...
