Articles | Volume 35, issue 5
https://doi.org/10.5194/angeo-35-1143-2017
© Author(s) 2017. 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-35-1143-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Regular paper
| 
24 Oct 2017
Regular paper |
| 24 Oct 2017
Plasma line observations from the EISCAT Svalbard Radar during the International Polar Year
School of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, Sweden
Nicola M. Schlatter
School of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, Sweden
Hanna Dahlgren
School of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, Sweden
School of Physics and Astronomy, University of Southampton, Southampton, UK
Yasunobu Ogawa
National Institute of Polar Research, Tokyo, Japan
Yuka Sato
National Institute of Polar Research, Tokyo, Japan
Ingemar Häggström
EISCAT Scientific Association, Kiruna, Sweden
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Daniel K. Whiter, Hanna Sundberg, Betty S. Lanchester, Joshua Dreyer, Noora Partamies, Nickolay Ivchenko, Marco Zaccaria Di Fraia, Rosie Oliver, Amanda Serpell-Stevens, Tiffany Shaw-Diaz, and Thomas Braunersreuther
Ann. Geophys., 39, 975–989, https://doi.org/10.5194/angeo-39-975-2021, https://doi.org/10.5194/angeo-39-975-2021, 2021
Short summary
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This paper presents an analysis of high-resolution optical and radar observations of a phenomenon called fragmented aurora-like emissions (FAEs) observed close to aurora in the high Arctic. The observations suggest that FAEs are not caused by high-energy electrons or protons entering the atmosphere along Earth's magnetic field and are, therefore, not aurora. The speeds of the FAEs and their internal dynamics were measured and used to evaluate theories for how the FAEs are produced.
Florine Enengl, Noora Partamies, Nickolay Ivchenko, and Lisa Baddeley
Ann. Geophys., 39, 795–809, https://doi.org/10.5194/angeo-39-795-2021, https://doi.org/10.5194/angeo-39-795-2021, 2021
Short summary
Short summary
Energetic particle precipitation has the potential to change the neutral atmospheric temperature at the bottom of the ionosphere. We have searched for events and investigated a possible correlation between lower-ionosphere electron density enhancements and simultaneous neutral temperature changes. Six of the 10 analysed events are associated with a temperature decrease of 10–20K. The events change the chemical composition in the mesosphere, and the temperatures are probed at lower altitudes.
Minna Palmroth, Maxime Grandin, Theodoros Sarris, Eelco Doornbos, Stelios Tourgaidis, Anita Aikio, Stephan Buchert, Mark A. Clilverd, Iannis Dandouras, Roderick Heelis, Alex Hoffmann, Nickolay Ivchenko, Guram Kervalishvili, David J. Knudsen, Anna Kotova, Han-Li Liu, David M. Malaspina, Günther March, Aurélie Marchaudon, Octav Marghitu, Tomoko Matsuo, Wojciech J. Miloch, Therese Moretto-Jørgensen, Dimitris Mpaloukidis, Nils Olsen, Konstantinos Papadakis, Robert Pfaff, Panagiotis Pirnaris, Christian Siemes, Claudia Stolle, Jonas Suni, Jose van den IJssel, Pekka T. Verronen, Pieter Visser, and Masatoshi Yamauchi
Ann. Geophys., 39, 189–237, https://doi.org/10.5194/angeo-39-189-2021, https://doi.org/10.5194/angeo-39-189-2021, 2021
Short summary
Short summary
This is a review paper that summarises the current understanding of the lower thermosphere–ionosphere (LTI) in terms of measurements and modelling. The LTI is the transition region between space and the atmosphere and as such of tremendous importance to both the domains of space and atmosphere. The paper also serves as the background for European Space Agency Earth Explorer 10 candidate mission Daedalus.
Sam Tuttle, Betty Lanchester, Björn Gustavsson, Daniel Whiter, Nickolay Ivchenko, Robert Fear, and Mark Lester
Ann. Geophys., 38, 845–859, https://doi.org/10.5194/angeo-38-845-2020, https://doi.org/10.5194/angeo-38-845-2020, 2020
Short summary
Short summary
Electric fields in the atmosphere near dynamic aurora are important in the physics of the electric circuit within the Earth's magnetic field. Oxygen ions emit light as they move under the influence of these electric fields; the flow of this emission is used to find the electric field at high temporal resolution. The solution needs two other simultaneous measurements of auroral emissions to give key parameters such as the auroral energy. The electric fields increase with brightness of the aurora.
Gabriel Giono, Boris Strelnikov, Heiner Asmus, Tristan Staszak, Nickolay Ivchenko, and Franz-Josef Lübken
Atmos. Meas. Tech., 11, 5299–5314, https://doi.org/10.5194/amt-11-5299-2018, https://doi.org/10.5194/amt-11-5299-2018, 2018
Short summary
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Energetic photons, such as ultraviolet light, are able to eject electrons from a material surface, thus creating an electrical current, also called a photocurrent. A proper estimation of this photocurrent can be crucial for space- or rocket-borne particle detectors, as it can dominate over the currents that are of scientific interest (induced by charged particles, for example). This article outlines the design for photocurrent modelling and for experimental confirmation in a laboratory.
Yunxia Yuan, Nickolay Ivchenko, Gunnar Tibert, Marin Stanev, Jonas Hedin, and Jörg Gumbel
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2017-91, https://doi.org/10.5194/amt-2017-91, 2017
Revised manuscript has not been submitted
Short summary
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The paper presents a method to determine altitude profile of atmospheric density, temperature and wind by means of analysing the reconstructed trajectory of a rigid falling sphere released from a sounding rocket. The trajectory reconstruction is achieved by post-flight analysis of GPS raw data gathered in the sphere. A comparison of the results with independent measurements is presented, with good agreement of the falling sphere results with other sources in the stratosphere.
Hanna Dahlgren, Betty S. Lanchester, Nickolay Ivchenko, and Daniel K. Whiter
Ann. Geophys., 35, 493–503, https://doi.org/10.5194/angeo-35-493-2017, https://doi.org/10.5194/angeo-35-493-2017, 2017
Short summary
Short summary
Pulsating aurora are ubiquitous events that constitute a large amount of energy transfer to the ionosphere. Still there are unsolved issues regarding their formation. Using high-resolution optical and radar data, we find that it is the flux of high-energy electrons that get reduced during the OFF period of the pulsations. We also report on dips in brightness at the transition between ON and OFF, and asymmetric rise and fall times, which may have implications for understanding the pulsations.
Hanna Dahlgren, Nicola M. Schlatter, Nickolay Ivchenko, Lorenz Roth, and Alexander Karlsson
Ann. Geophys., 35, 475–479, https://doi.org/10.5194/angeo-35-475-2017, https://doi.org/10.5194/angeo-35-475-2017, 2017
Short summary
Short summary
Anomalous strong echoes with three frequency peaks are occasionally seen with incoherent scatter radars in the ionosphere near 200 km altitude at high latitudes. We investigate how they relate to electron precipitation, by finding the resulting peak electron density and the height of the peak, respectively. We find that occurrence rate increases with density and decreases with height, indicating a correlation between the echoes and precipitating electrons with high energy and energy flux.
N. M. Schlatter, V. Belyey, B. Gustavsson, N. Ivchenko, D. Whiter, H. Dahlgren, S. Tuttle, and T. Grydeland
Ann. Geophys., 33, 837–844, https://doi.org/10.5194/angeo-33-837-2015, https://doi.org/10.5194/angeo-33-837-2015, 2015
Short summary
Short summary
The high-latitude ionosphere is a dynamic region where particle precipitation leads to various phenomena including wave instability and turbulence. Anomalous echoes related to aurora are observed in ground-based radar observations of the ionosphere. These echoes indicate enhanced ion acoustic fluctuations. In this article, we show that the origin of the echo is located in or close to the region of particle precipitation and that the echo region itself is limited to hundreds of meters.
N. M. Schlatter, N. Ivchenko, T. Sergienko, B. Gustavsson, and B. U. E. Brändström
Ann. Geophys., 31, 1681–1687, https://doi.org/10.5194/angeo-31-1681-2013, https://doi.org/10.5194/angeo-31-1681-2013, 2013
N. M. Schlatter, N. Ivchenko, B. Gustavsson, T. Leyser, and M. Rietveld
Ann. Geophys., 31, 1103–1108, https://doi.org/10.5194/angeo-31-1103-2013, https://doi.org/10.5194/angeo-31-1103-2013, 2013
W. Reid, P. Achtert, N. Ivchenko, P. Magnusson, T. Kuremyr, V. Shepenkov, and G. Tibert
Atmos. Meas. Tech., 6, 777–785, https://doi.org/10.5194/amt-6-777-2013, https://doi.org/10.5194/amt-6-777-2013, 2013
Yoshimasa Tanaka, Yasunobu Ogawa, Akira Kadokura, Takehiko Aso, Björn Gustavsson, Urban Brändström, Tima Sergienko, Genta Ueno, and Satoko Saita
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-35, https://doi.org/10.5194/angeo-2023-35, 2023
Revised manuscript accepted for ANGEO
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We present by simulation how useful monochromatic images taken by a multi-point imager network are for auroral research in the EISCAT_3D project. We apply the generalized-aurora computed tomography (G-ACT) method to modelled multiple auroral images and ionospheric electron density data. It is demonstrated that the G-ACT provides better reconstruction results than the normal ACT and can interpolate ionospheric electron density at a much higher spatial resolution than observed by EISCAT_3D radar.
Mizuki Fukizawa, Yoshimasa Tanaka, Yasunobu Ogawa, Keisuke Hosokawa, Tero Raita, and Kirsti Kauristie
Ann. Geophys., 41, 511–528, https://doi.org/10.5194/angeo-41-511-2023, https://doi.org/10.5194/angeo-41-511-2023, 2023
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We use computed tomography to reconstruct the three-dimensional distributions of the Hall and Pedersen conductivities of pulsating auroras, a key research target for understanding the magnetosphere–ionosphere coupling process. It is suggested that the high-energy electron precipitation associated with pulsating auroras may have a greater impact on the closure of field-aligned currents in the ionosphere than has been previously reported.
Tinna Lif Gunnarsdottir, Ingrid Mann, Wuhu Feng, Devin R. Huyghebaert, Ingemar Haeggstroem, Yasunobu Ogawa, Norihito Saito, Satonori Nozawa, and Takuya D. Kawahara
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-29, https://doi.org/10.5194/angeo-2023-29, 2023
Revised manuscript accepted for ANGEO
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Several tons of meteoric particles burn up in our atmosphere each day. This deposits a great deal of material that bids with other atmospheric particles and forms so-called Meteoric Smoke Particles. These particles are assumed to influence radar measurements. Here we have compared radar measurements with simulations of a radar spectrum with and without dust particles and found that dust influences the radar spectrum in the altitude range of 75–85 km.
Tinna L. Gunnarsdottir, Arne Poggenpohl, Ingrid Mann, Alireza Mahmoudian, Peter Dalin, Ingemar Haeggstroem, and Michael Rietveld
Ann. Geophys., 41, 93–114, https://doi.org/10.5194/angeo-41-93-2023, https://doi.org/10.5194/angeo-41-93-2023, 2023
Short summary
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Temperatures at 85 km around Earth's poles in summer can be so cold that small ice particles form. These can become charged, and, combined with turbulence at these altitudes, they can influence the many electrons present. This can cause large radar echoes called polar mesospheric summer echoes. We use radio waves to heat these echoes on and off when the sun is close to or below the horizon. This allows us to gain some insight into these ice particles and how the sun influences the echoes.
Mizuki Fukizawa, Takeshi Sakanoi, Yoshimasa Tanaka, Yasunobu Ogawa, Keisuke Hosokawa, Björn Gustavsson, Kirsti Kauristie, Alexander Kozlovsky, Tero Raita, Urban Brändström, and Tima Sergienko
Ann. Geophys., 40, 475–484, https://doi.org/10.5194/angeo-40-475-2022, https://doi.org/10.5194/angeo-40-475-2022, 2022
Short summary
Short summary
The pulsating auroral generation mechanism has been investigated by observing precipitating electrons using rockets or satellites. However, it is difficult for such observations to distinguish temporal changes from spatial ones. In this study, we reconstructed the horizontal 2-D distribution of precipitating electrons using only auroral images. The 3-D aurora structure was also reconstructed. We found that there were both spatial and temporal changes in the precipitating electron energy.
Fasil Tesema, Noora Partamies, Daniel K. Whiter, and Yasunobu Ogawa
Ann. Geophys., 40, 1–10, https://doi.org/10.5194/angeo-40-1-2022, https://doi.org/10.5194/angeo-40-1-2022, 2022
Short summary
Short summary
In this study, we present the comparison between an auroral model and EISCAT radar electron densities during pulsating aurorae. We test whether an overpassing satellite measurement of the average energy spectrum is a reasonable estimate for pulsating aurora electron precipitation. When patchy pulsating aurora is dominant in the morning sector, the overpass-averaged spectrum is found to be a reasonable estimate – but not when there is a mix of pulsating aurora types in the post-midnight sector.
Daniel K. Whiter, Hanna Sundberg, Betty S. Lanchester, Joshua Dreyer, Noora Partamies, Nickolay Ivchenko, Marco Zaccaria Di Fraia, Rosie Oliver, Amanda Serpell-Stevens, Tiffany Shaw-Diaz, and Thomas Braunersreuther
Ann. Geophys., 39, 975–989, https://doi.org/10.5194/angeo-39-975-2021, https://doi.org/10.5194/angeo-39-975-2021, 2021
Short summary
Short summary
This paper presents an analysis of high-resolution optical and radar observations of a phenomenon called fragmented aurora-like emissions (FAEs) observed close to aurora in the high Arctic. The observations suggest that FAEs are not caused by high-energy electrons or protons entering the atmosphere along Earth's magnetic field and are, therefore, not aurora. The speeds of the FAEs and their internal dynamics were measured and used to evaluate theories for how the FAEs are produced.
Florine Enengl, Noora Partamies, Nickolay Ivchenko, and Lisa Baddeley
Ann. Geophys., 39, 795–809, https://doi.org/10.5194/angeo-39-795-2021, https://doi.org/10.5194/angeo-39-795-2021, 2021
Short summary
Short summary
Energetic particle precipitation has the potential to change the neutral atmospheric temperature at the bottom of the ionosphere. We have searched for events and investigated a possible correlation between lower-ionosphere electron density enhancements and simultaneous neutral temperature changes. Six of the 10 analysed events are associated with a temperature decrease of 10–20K. The events change the chemical composition in the mesosphere, and the temperatures are probed at lower altitudes.
Minna Palmroth, Maxime Grandin, Theodoros Sarris, Eelco Doornbos, Stelios Tourgaidis, Anita Aikio, Stephan Buchert, Mark A. Clilverd, Iannis Dandouras, Roderick Heelis, Alex Hoffmann, Nickolay Ivchenko, Guram Kervalishvili, David J. Knudsen, Anna Kotova, Han-Li Liu, David M. Malaspina, Günther March, Aurélie Marchaudon, Octav Marghitu, Tomoko Matsuo, Wojciech J. Miloch, Therese Moretto-Jørgensen, Dimitris Mpaloukidis, Nils Olsen, Konstantinos Papadakis, Robert Pfaff, Panagiotis Pirnaris, Christian Siemes, Claudia Stolle, Jonas Suni, Jose van den IJssel, Pekka T. Verronen, Pieter Visser, and Masatoshi Yamauchi
Ann. Geophys., 39, 189–237, https://doi.org/10.5194/angeo-39-189-2021, https://doi.org/10.5194/angeo-39-189-2021, 2021
Short summary
Short summary
This is a review paper that summarises the current understanding of the lower thermosphere–ionosphere (LTI) in terms of measurements and modelling. The LTI is the transition region between space and the atmosphere and as such of tremendous importance to both the domains of space and atmosphere. The paper also serves as the background for European Space Agency Earth Explorer 10 candidate mission Daedalus.
Sam Tuttle, Betty Lanchester, Björn Gustavsson, Daniel Whiter, Nickolay Ivchenko, Robert Fear, and Mark Lester
Ann. Geophys., 38, 845–859, https://doi.org/10.5194/angeo-38-845-2020, https://doi.org/10.5194/angeo-38-845-2020, 2020
Short summary
Short summary
Electric fields in the atmosphere near dynamic aurora are important in the physics of the electric circuit within the Earth's magnetic field. Oxygen ions emit light as they move under the influence of these electric fields; the flow of this emission is used to find the electric field at high temporal resolution. The solution needs two other simultaneous measurements of auroral emissions to give key parameters such as the auroral energy. The electric fields increase with brightness of the aurora.
Jun Wu, Jian Wu, Michael T. Rietveld, Ingemar Haggstrom, Haisheng Zhao, Tong Xu, and Zhengwen Xu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-23, https://doi.org/10.5194/angeo-2019-23, 2019
Manuscript not accepted for further review
Gabriel Giono, Boris Strelnikov, Heiner Asmus, Tristan Staszak, Nickolay Ivchenko, and Franz-Josef Lübken
Atmos. Meas. Tech., 11, 5299–5314, https://doi.org/10.5194/amt-11-5299-2018, https://doi.org/10.5194/amt-11-5299-2018, 2018
Short summary
Short summary
Energetic photons, such as ultraviolet light, are able to eject electrons from a material surface, thus creating an electrical current, also called a photocurrent. A proper estimation of this photocurrent can be crucial for space- or rocket-borne particle detectors, as it can dominate over the currents that are of scientific interest (induced by charged particles, for example). This article outlines the design for photocurrent modelling and for experimental confirmation in a laboratory.
Yunxia Yuan, Nickolay Ivchenko, Gunnar Tibert, Marin Stanev, Jonas Hedin, and Jörg Gumbel
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2017-91, https://doi.org/10.5194/amt-2017-91, 2017
Revised manuscript has not been submitted
Short summary
Short summary
The paper presents a method to determine altitude profile of atmospheric density, temperature and wind by means of analysing the reconstructed trajectory of a rigid falling sphere released from a sounding rocket. The trajectory reconstruction is achieved by post-flight analysis of GPS raw data gathered in the sphere. A comparison of the results with independent measurements is presented, with good agreement of the falling sphere results with other sources in the stratosphere.
Hanna Dahlgren, Betty S. Lanchester, Nickolay Ivchenko, and Daniel K. Whiter
Ann. Geophys., 35, 493–503, https://doi.org/10.5194/angeo-35-493-2017, https://doi.org/10.5194/angeo-35-493-2017, 2017
Short summary
Short summary
Pulsating aurora are ubiquitous events that constitute a large amount of energy transfer to the ionosphere. Still there are unsolved issues regarding their formation. Using high-resolution optical and radar data, we find that it is the flux of high-energy electrons that get reduced during the OFF period of the pulsations. We also report on dips in brightness at the transition between ON and OFF, and asymmetric rise and fall times, which may have implications for understanding the pulsations.
Hanna Dahlgren, Nicola M. Schlatter, Nickolay Ivchenko, Lorenz Roth, and Alexander Karlsson
Ann. Geophys., 35, 475–479, https://doi.org/10.5194/angeo-35-475-2017, https://doi.org/10.5194/angeo-35-475-2017, 2017
Short summary
Short summary
Anomalous strong echoes with three frequency peaks are occasionally seen with incoherent scatter radars in the ionosphere near 200 km altitude at high latitudes. We investigate how they relate to electron precipitation, by finding the resulting peak electron density and the height of the peak, respectively. We find that occurrence rate increases with density and decreases with height, indicating a correlation between the echoes and precipitating electrons with high energy and energy flux.
T. Takahashi, S. Nozawa, T. T. Tsuda, Y. Ogawa, N. Saito, T. Hidemori, T. D. Kawahara, C. Hall, H. Fujiwara, N. Matuura, A. Brekke, M. Tsutsumi, S. Wada, T. Kawabata, S. Oyama, and R. Fujii
Ann. Geophys., 33, 941–953, https://doi.org/10.5194/angeo-33-941-2015, https://doi.org/10.5194/angeo-33-941-2015, 2015
N. M. Schlatter, V. Belyey, B. Gustavsson, N. Ivchenko, D. Whiter, H. Dahlgren, S. Tuttle, and T. Grydeland
Ann. Geophys., 33, 837–844, https://doi.org/10.5194/angeo-33-837-2015, https://doi.org/10.5194/angeo-33-837-2015, 2015
Short summary
Short summary
The high-latitude ionosphere is a dynamic region where particle precipitation leads to various phenomena including wave instability and turbulence. Anomalous echoes related to aurora are observed in ground-based radar observations of the ionosphere. These echoes indicate enhanced ion acoustic fluctuations. In this article, we show that the origin of the echo is located in or close to the region of particle precipitation and that the echo region itself is limited to hundreds of meters.
T. Ishida, Y. Ogawa, A. Kadokura, K. Hosokawa, and Y. Otsuka
Ann. Geophys., 33, 525–530, https://doi.org/10.5194/angeo-33-525-2015, https://doi.org/10.5194/angeo-33-525-2015, 2015
Short summary
Short summary
We studied the localized plasma density enhancements called blobs, which are often produced in the high-latitude ionosphere by the transportation process of plasma or particle precipitations. This subject is important because such structures affect radio wave propagation and can cause scintillation of GNSS signals in the deformation process. This paper is the first report of direct observations of blob deformation during a substorm.
H. Fujiwara, S. Nozawa, Y. Ogawa, R. Kataoka, Y. Miyoshi, H. Jin, and H. Shinagawa
Ann. Geophys., 32, 831–839, https://doi.org/10.5194/angeo-32-831-2014, https://doi.org/10.5194/angeo-32-831-2014, 2014
N. M. Schlatter, N. Ivchenko, T. Sergienko, B. Gustavsson, and B. U. E. Brändström
Ann. Geophys., 31, 1681–1687, https://doi.org/10.5194/angeo-31-1681-2013, https://doi.org/10.5194/angeo-31-1681-2013, 2013
N. M. Schlatter, N. Ivchenko, B. Gustavsson, T. Leyser, and M. Rietveld
Ann. Geophys., 31, 1103–1108, https://doi.org/10.5194/angeo-31-1103-2013, https://doi.org/10.5194/angeo-31-1103-2013, 2013
W. Reid, P. Achtert, N. Ivchenko, P. Magnusson, T. Kuremyr, V. Shepenkov, and G. Tibert
Atmos. Meas. Tech., 6, 777–785, https://doi.org/10.5194/amt-6-777-2013, https://doi.org/10.5194/amt-6-777-2013, 2013
Short summary
Photo-electrons and secondary electrons from particle precipitation enhance the incoherent scatter plasma line to levels sufficient for detection. A plasma line gives an accurate measure of the electron density and can be used to estimate electron temperature. The occurrence of plasma line enhancements in the EISCAT Svalbard Radar data was investigated. During summer daytime hours the plasma line is detectable in up to 90 % of the data. In winter time the occurrence is a few percent.
Photo-electrons and secondary electrons from particle precipitation enhance the incoherent...
