Articles | Volume 12, issue 1
https://doi.org/10.5194/gi-12-71-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gi-12-71-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Auroral alert version 1.0: two-step automatic detection of sudden aurora intensification from all-sky JPEG images
Swedish Institute of Space Physics, Bengt Hultqvist vägen 1, P.O. Box 812, 98128 Kiruna, Sweden
Urban Brändström
Swedish Institute of Space Physics, Bengt Hultqvist vägen 1, P.O. Box 812, 98128 Kiruna, Sweden
Related authors
Sota Nanjo, Masatoshi Yamauchi, Magnar Gullikstad Johnsen, Yoshihiro Yokoyama, Urban Brändström, Yasunobu Ogawa, Anna Naemi Willer, and Keisuke Hosokawa
EGUsphere, https://doi.org/10.5194/egusphere-2024-3277, https://doi.org/10.5194/egusphere-2024-3277, 2024
Short summary
Short summary
Our research explored the "shock aurora," caused by the impact of solar wind particles on Earth's magnetic field. On February 26, 2023, we observed this rare event on the nightside, where such observations are difficult. Ground-based cameras revealed new structural features, including undulating and jumping patterns. These results provide fresh insights into the complex interactions between the solar wind and Earth's magnetosphere, enhancing our understanding of space weather effects.
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.
Masatoshi Yamauchi, Magnar G. Johnsen, Carl-Fredrik Enell, Anders Tjulin, Anna Willer, and Dmitry A. Sormakov
Ann. Geophys., 38, 1159–1170, https://doi.org/10.5194/angeo-38-1159-2020, https://doi.org/10.5194/angeo-38-1159-2020, 2020
Short summary
Short summary
The paper reports a new finding on space weather effects at around 70–75 ° geographic latitudes. We found that X flares cause an unexpectedly strong ionospheric current driven by solar flares. The effect is as large as a substorm that is known to cause strong auroras and may enhance ongoing substorms. However, it has been overlooked in the past due to the narrow latitudinal range at high latitudes. Since severe magnetic storms often occur with X flares, this may cause geomagnetic hazards.
Masatoshi Yamauchi
Ann. Geophys., 37, 1197–1222, https://doi.org/10.5194/angeo-37-1197-2019, https://doi.org/10.5194/angeo-37-1197-2019, 2019
Short summary
Short summary
Terrestrial ion transport and total escape are synthesized, with stress on the high-latitude polar region and the inner magnetosphere where Custer significantly improved knowledge. After estimating the outflow flux and destinations, complicated ion dynamics in the inner magnetosphere was classified and summarized, through which more than half the O+ is finally lost to space. Together with direct escapes, total O+ escape is high enough to influence the evolution of the biosphere.
Masatoshi Yamauchi and Rikard Slapak
Ann. Geophys., 36, 1–12, https://doi.org/10.5194/angeo-36-1-2018, https://doi.org/10.5194/angeo-36-1-2018, 2018
Short summary
Short summary
Extraction of the solar wind kinetic energy (∆K) by mass loading of escaping O+ is modelled in the exterior cusp and plasma mantle of the Earth. We found ∆K proportional to mass flux of escaping ions and square of solar wind velocity, but independent to the other parameters. The amount is sufficient to power the cusp field-aligned currents, further enhancing ion escape through Joule heating of the ionospheric ions, completing positive feedback to enhance escape with geomagnetic activities.
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
Short summary
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
Short summary
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
Short summary
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.
M. Yamauchi, Y. Ebihara, H. Nilsson, and I. Dandouras
Ann. Geophys., 32, 83–90, https://doi.org/10.5194/angeo-32-83-2014, https://doi.org/10.5194/angeo-32-83-2014, 2014
M. Yamauchi, I. Dandouras, H. Rème, R. Lundin, and L. M. Kistler
Ann. Geophys., 31, 1569–1578, https://doi.org/10.5194/angeo-31-1569-2013, https://doi.org/10.5194/angeo-31-1569-2013, 2013
Sota Nanjo, Masatoshi Yamauchi, Magnar Gullikstad Johnsen, Yoshihiro Yokoyama, Urban Brändström, Yasunobu Ogawa, Anna Naemi Willer, and Keisuke Hosokawa
EGUsphere, https://doi.org/10.5194/egusphere-2024-3277, https://doi.org/10.5194/egusphere-2024-3277, 2024
Short summary
Short summary
Our research explored the "shock aurora," caused by the impact of solar wind particles on Earth's magnetic field. On February 26, 2023, we observed this rare event on the nightside, where such observations are difficult. Ground-based cameras revealed new structural features, including undulating and jumping patterns. These results provide fresh insights into the complex interactions between the solar wind and Earth's magnetosphere, enhancing our understanding of space weather effects.
Yoshimasa Tanaka, Yasunobu Ogawa, Akira Kadokura, Takehiko Aso, Björn Gustavsson, Urban Brändström, Tima Sergienko, Genta Ueno, and Satoko Saita
Ann. Geophys., 42, 179–190, https://doi.org/10.5194/angeo-42-179-2024, https://doi.org/10.5194/angeo-42-179-2024, 2024
Short summary
Short summary
We present via 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) to modeled multiple auroral images and ionospheric electron density data. It is demonstrated that 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 the EISCAT_3D radar.
Peter Dalin, Urban Brändström, Johan Kero, Peter Voelger, Takanori Nishiyama, Trond Trondsen, Devin Wyatt, Craig Unick, Vladimir Perminov, Nikolay Pertsev, and Jonas Hedin
Atmos. Meas. Tech., 17, 1561–1576, https://doi.org/10.5194/amt-17-1561-2024, https://doi.org/10.5194/amt-17-1561-2024, 2024
Short summary
Short summary
A novel infrared imaging instrument (OH imager) was put into operation in November 2022 at the Swedish Institute of Space Physics in Kiruna (Sweden). The OH imager is dedicated to the study of nightglow emissions coming from the hydroxyl (OH) and molecular oxygen (O2) layers in the mesopause (80–100 km). Based on a brightness ratio of two OH emission lines, the neutral temperature is estimated at around 87 km. The average daily winter temperature for the period January–April 2023 is 203±10 K.
Thomas B. Leyser, Tima Sergienko, Urban Brändström, Björn Gustavsson, and Michael T. Rietveld
Ann. Geophys., 41, 589–600, https://doi.org/10.5194/angeo-41-589-2023, https://doi.org/10.5194/angeo-41-589-2023, 2023
Short summary
Short summary
Powerful radio waves transmitted into the ionosphere from the ground were used to study electron energization in the pumped ionospheric plasma turbulence, by detecting optical emissions from atomic oxygen. Our results obtained with the EISCAT (European Incoherent Scatter Scientific Association) facilities in northern Norway and optical detection with the ALIS (Auroral Large Imaging System) in northern Sweden suggest that long-wavelength upper hybrid waves are important in accelerating electrons.
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.
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.
Masatoshi Yamauchi, Magnar G. Johnsen, Carl-Fredrik Enell, Anders Tjulin, Anna Willer, and Dmitry A. Sormakov
Ann. Geophys., 38, 1159–1170, https://doi.org/10.5194/angeo-38-1159-2020, https://doi.org/10.5194/angeo-38-1159-2020, 2020
Short summary
Short summary
The paper reports a new finding on space weather effects at around 70–75 ° geographic latitudes. We found that X flares cause an unexpectedly strong ionospheric current driven by solar flares. The effect is as large as a substorm that is known to cause strong auroras and may enhance ongoing substorms. However, it has been overlooked in the past due to the narrow latitudinal range at high latitudes. Since severe magnetic storms often occur with X flares, this may cause geomagnetic hazards.
Masatoshi Yamauchi
Ann. Geophys., 37, 1197–1222, https://doi.org/10.5194/angeo-37-1197-2019, https://doi.org/10.5194/angeo-37-1197-2019, 2019
Short summary
Short summary
Terrestrial ion transport and total escape are synthesized, with stress on the high-latitude polar region and the inner magnetosphere where Custer significantly improved knowledge. After estimating the outflow flux and destinations, complicated ion dynamics in the inner magnetosphere was classified and summarized, through which more than half the O+ is finally lost to space. Together with direct escapes, total O+ escape is high enough to influence the evolution of the biosphere.
Masatoshi Yamauchi and Rikard Slapak
Ann. Geophys., 36, 1–12, https://doi.org/10.5194/angeo-36-1-2018, https://doi.org/10.5194/angeo-36-1-2018, 2018
Short summary
Short summary
Extraction of the solar wind kinetic energy (∆K) by mass loading of escaping O+ is modelled in the exterior cusp and plasma mantle of the Earth. We found ∆K proportional to mass flux of escaping ions and square of solar wind velocity, but independent to the other parameters. The amount is sufficient to power the cusp field-aligned currents, further enhancing ion escape through Joule heating of the ionospheric ions, completing positive feedback to enhance escape with geomagnetic activities.
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
Short summary
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
Short summary
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
Short summary
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.
F. Sigernes, S. E. Holmen, D. Biles, H. Bjørklund, X. Chen, M. Dyrland, D. A. Lorentzen, L. Baddeley, T. Trondsen, U. Brändström, E. Trondsen, B. Lybekk, J. Moen, S. Chernouss, and C. S. Deehr
Geosci. Instrum. Method. Data Syst., 3, 241–245, https://doi.org/10.5194/gi-3-241-2014, https://doi.org/10.5194/gi-3-241-2014, 2014
Short summary
Short summary
A two-step procedure to calibrate the spectral sensitivity of auroral all-sky (fish-eye) cameras is outlined. First, center pixel response is obtained by the use of a Lambertian surface and a standard tungsten lamp. Second, all-sky flat-field correction is carried out with an integrating sphere.
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
M. Yamauchi, Y. Ebihara, H. Nilsson, and I. Dandouras
Ann. Geophys., 32, 83–90, https://doi.org/10.5194/angeo-32-83-2014, https://doi.org/10.5194/angeo-32-83-2014, 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
M. Yamauchi, I. Dandouras, H. Rème, R. Lundin, and L. M. Kistler
Ann. Geophys., 31, 1569–1578, https://doi.org/10.5194/angeo-31-1569-2013, https://doi.org/10.5194/angeo-31-1569-2013, 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
Related subject area
Image processing
Automatic detection of calving events from time-lapse imagery at Tunabreen, Svalbard
Integration of remote sensing and geographic information systems for geological fault detection on the island of Crete, Greece
Consideration of NDVI thematic changes in density analysis and floristic composition of Wadi Yalamlam, Saudi Arabia
Precise DEM extraction from Svalbard using 1936 high oblique imagery
A comparative study of auroral morphology distribution between the Northern and Southern Hemisphere based on automatic classification
Understanding of morphometric features for adequate water resource management in arid environments
Soil salinity mapping and hydrological drought indices assessment in arid environments based on remote sensing techniques
Realization of daily evapotranspiration in arid ecosystems based on remote sensing techniques
Digital photography for assessing the link between vegetation phenology and CO2 exchange in two contrasting northern ecosystems
Automatic georeferencing of astronaut auroral photography
Image georectification and feature tracking toolbox: ImGRAFT
Dorothée Vallot, Sigit Adinugroho, Robin Strand, Penelope How, Rickard Pettersson, Douglas I. Benn, and Nicholas R. J. Hulton
Geosci. Instrum. Method. Data Syst., 8, 113–127, https://doi.org/10.5194/gi-8-113-2019, https://doi.org/10.5194/gi-8-113-2019, 2019
Short summary
Short summary
This paper presents a novel method to quantify the sizes and frequency of calving events from time-lapse camera images. The calving front of a tidewater glacier experiences different episodes of iceberg deliveries that can be captured by a time-lapse camera situated in front of the glacier. An automatic way of detecting calving events is presented here and compared to manually detected events.
Mohamed Elhag and Dalal Alshamsi
Geosci. Instrum. Method. Data Syst., 8, 45–54, https://doi.org/10.5194/gi-8-45-2019, https://doi.org/10.5194/gi-8-45-2019, 2019
Short summary
Short summary
The article deals with the designation of fault detection on the island of Crete. The delineation is based on the integration method of remote sensing and GIS. The crucial finding is how to differentiate between faults and water streams. The results showed a robust approach to fault detection.
Amal Y. Aldhebiani, Mohamed Elhag, Ahmad K. Hegazy, Hanaa K. Galal, and Norah S. Mufareh
Geosci. Instrum. Method. Data Syst., 7, 297–306, https://doi.org/10.5194/gi-7-297-2018, https://doi.org/10.5194/gi-7-297-2018, 2018
Short summary
Short summary
The current article focuses on plant diversity assessment in arid environments. Species richness and species evenness equations were used to meet the objectives. Remote sensing techniques were used to detect normalized difference vegetation index (NDVI) temporal changes. Two datasets were used to realize the NDVI, and post-chance detection (PCC) techniques were used to evaluate plant diversity status over a period of 4 years. The results show a recognizable loss in plant biodiversity.
Luc Girod, Niels Ivar Nielsen, Frédérique Couderette, Christopher Nuth, and Andreas Kääb
Geosci. Instrum. Method. Data Syst., 7, 277–288, https://doi.org/10.5194/gi-7-277-2018, https://doi.org/10.5194/gi-7-277-2018, 2018
Short summary
Short summary
Historical surveys performed through the use of aerial photography gave us the first maps of the Arctic. Nearly a century later, a renewed interest in studying the Arctic is rising from the need to understand and quantify climate change. It is therefore time to dig up the archives and extract the maximum of information from the images using the most modern methods. In this study, we show that the aerial survey of Svalbard in 1936–38 provides us with valuable data on the archipelago's glaciers.
Qiuju Yang and Ze-Jun Hu
Geosci. Instrum. Method. Data Syst., 7, 113–122, https://doi.org/10.5194/gi-7-113-2018, https://doi.org/10.5194/gi-7-113-2018, 2018
Short summary
Short summary
Based on the morphological characteristics of the four dayside auroral types on images at the Chinese Arctic Yellow River Station (YRS), and by extracting the local binary pattern features and using k-nearest classifier, we make an automatic classification to the auroral images of the YRS and the South Pole Station and obtain the occurrence distribution of the dayside aurora morphology. The results indicate that these auroral types present similar occurrence distributions in the two stations.
Mohamed Elhag, Hanaa K. Galal, and Haneen Alsubaie
Geosci. Instrum. Method. Data Syst., 6, 293–300, https://doi.org/10.5194/gi-6-293-2017, https://doi.org/10.5194/gi-6-293-2017, 2017
Short summary
Short summary
This article focus on morphometric features and their role in water resource management at the basin scale. The estimation of the features requires an adequate understanding of DEM feature extractions. The findings of the current study will help decision makers to improve the adopted water resource management strategies in similar geographic locations.
Mohamed Elhag and Jarbou A. Bahrawi
Geosci. Instrum. Method. Data Syst., 6, 149–158, https://doi.org/10.5194/gi-6-149-2017, https://doi.org/10.5194/gi-6-149-2017, 2017
Short summary
Short summary
The current work is aimed at the quantification of the hydrological drought indices' response to soil salinity. Work has been done to overcome the problems of soil salinity on a large scale for better water resource management, especially in arid environments.
Mohamed Elhag and Jarbou A. Bahrawi
Geosci. Instrum. Method. Data Syst., 6, 141–147, https://doi.org/10.5194/gi-6-141-2017, https://doi.org/10.5194/gi-6-141-2017, 2017
Short summary
Short summary
Work has been done to overcome the problems of evapotranspiration on a large scale for better water resources management, especially in arid environments.
Maiju Linkosalmi, Mika Aurela, Juha-Pekka Tuovinen, Mikko Peltoniemi, Cemal M. Tanis, Ali N. Arslan, Pasi Kolari, Kristin Böttcher, Tuula Aalto, Juuso Rainne, Juha Hatakka, and Tuomas Laurila
Geosci. Instrum. Method. Data Syst., 5, 417–426, https://doi.org/10.5194/gi-5-417-2016, https://doi.org/10.5194/gi-5-417-2016, 2016
Short summary
Short summary
Digital photography has become a widely used tool for monitoring the vegetation phenology. The seasonal cycle of the greenness index obtained from photographs correlated well with the CO2 exchange of the plants at our wetland and Scots pine forest sites. While the seasonal changes in the greenness were more obvious for the ecosystem dominated by annual plants, clear seasonal patterns were also observed for the evergreen forest.
Maik Riechert, Andrew P. Walsh, Alexander Gerst, and Matthew G. G. T. Taylor
Geosci. Instrum. Method. Data Syst., 5, 289–304, https://doi.org/10.5194/gi-5-289-2016, https://doi.org/10.5194/gi-5-289-2016, 2016
Short summary
Short summary
Astronauts on board the International Space Station have taken thousands of high-quality images of the northern and southern lights (aurorae). Because the images were not taken as part of a specific research project, no information about exactly where the camera was pointing was available. We have used the stars in the images to reconstruct this information. Now we can tell the latitudes and longitudes of the aurorae in the images and use them for research. The data are publicly available.
A. Messerli and A. Grinsted
Geosci. Instrum. Method. Data Syst., 4, 23–34, https://doi.org/10.5194/gi-4-23-2015, https://doi.org/10.5194/gi-4-23-2015, 2015
Short summary
Short summary
The use of time-lapse cameras is becoming an ever more popular method of observing changes in the natural environment. This study provides an overview of the newly developed Image GeoRectification And Feature Tracking toolbox (ImGRAFT). The paper outlines the main function of the toolbox and describes each of the key processes needed to transform a pair of terrestrial time-lapse images into a velocity field. The tool is presented using a case study of glacier surface motion at Engabreen, Norway.
Cited articles
Akasofu, S.-I.: The development of the auroral substorm, Planet. Space Sci., 12, 273–282, https://doi.org/10.1016/0032-0633(64)90151-5, 1964.
Akasofu, S.-I.: Physics of magnetospheric substorms, in: Astrophysics and space science library, vol. 47, Reidel, Dordrecht,
https://doi.org/10.1007/978-94-010-1164-8, 1977.
Brändström, B. U. E., Enell, C.-F., Widell, O., Hansson, T., Whiter, D., Mäkinen, S., Mikhaylova, D., Axelsson, K., Sigernes, F., Gulbrandsen, N., Schlatter, N. M., Gjendem, A. G., Cai, L., Reistad, J. P., Daae, M., Demissie, T. D., Andalsvik, Y. L., Roberts, O., Poluyanov, S., and Chernouss, S.: Results from the intercalibration of optical low light calibration sources 2011, Geosci. Instrum. Method. Data Syst., 1, 43–51,
https://doi.org/10.5194/gi-1-43-2012, 2012.
Breiman, L.: Random Forests, Mach. Learn., 45, 5–32, https://doi.org/10.1023/A:1010933404324, 2001.
Clausen, L. B. N. and Nickisch, H.: Automatic classification of auroral images from the Oslo Auroral THEMIS (OATH) data set using machine learning, J. Geophys. Res., 123, 5640–5647,https://doi.org/10.1029/2018JA025274, 2018.
Friis-Christensen, E., McHenry, M. A., Clauer, C. R., and Vennerstrom, S.: Ionospheric traveling convection vortices observed near the polar cleft: a triggered response to sudden changes in the solar wind, Geophys. Res. Lett., 15, 253–256, https://doi.org/10.1029/GL015i003p00253, 1988.
Helmholtz – German Research Centre for Geoscience (GFZ): Real-time Kp, https://isdc.gfz-potsdam.de/kp-index/ (ast access: 11 April 2023), 2022.
Juusola, L., Vanhamäki, H., Viljanen, A., and Smirnov, M.: Induced currents due to 3D ground conductivity play a major role in the interpretation of geomagnetic variations, Ann. Geophys., 38, 983–998,
https://doi.org/10.5194/angeo-38-983-2020, 2020.
Kvammen, A., Wickstrøm, K., McKay, D., and Partamies, N.: Auroral image classification with deep neural networks. J. Geophys. Res., 125, e2020JA027808, https://doi.org/10.1029/2020JA027808, 2020.
Liu, C., Deng, N., Wang, J. T. L. ,and Wang, H.: Predicting solar flares using SDO/HMI vector magnetic data products and the random forest algorithm, Astrophys. J., 843, 104, https://doi.org/10.3847/1538-4357/aa789b, 2017.
Luhr, H., Aylward, A., Bucher, S. C., Pajunpaa, A., Pajunpaa, K., Holmboe, T., and Zalewski, S. M.: Westward moving dynamic substorm features observed with the IMAGE magnetometer network and other ground-based instruments, Ann. Geophys., 16, 425–440, https://doi.org/10.1007/s00585-998-0425-y, 1998.
Nanjo, S., Satonori Nozawa, S., Yamamoto, M., Kawabata T., Johnsen, M. G., Tsuda, T. T., and Hosokawa, K.: An a auroral detection system using deep learning: real-time operation in Tromsø, Norway, Sci. Rep., 12, 8038,
https://doi.org/10.1038/s41598-022-11686-8, 2022.
Partamies, N., Amm, O., Kauristie, K., Pulkkinen, T. I., and Tanskanen, E.: A pseudo-breakup observation: Localized currentwedge across the postmidnight auroral oval, J. Geophys. Res., 108, 1020, https://doi.org/10.1029/2002JA009276, 2003.
Sigernes, F., Holmen, S. E., Biles, D., Bjørklund, H., Chen, X., Dyrland, M., Lorentzen, D. A., Baddeley, L., Trondsen, T., Brändström, U., Trondsen, E., Lybekk, B., Moen, J., Chernouss, S., and Deehr, C. S.: Auroral all-sky camera calibration, Geosci. Instrum. Method. Data Syst., 3, 241–245,
https://doi.org/10.5194/gi-3-241-2014, 2014.
Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO): Real-time and archived data, Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO) [data set], https://www.irf.se/en/about-irf/data/ (last access: 11 April 2023), 2023a.
Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO): All-sky camera in Kiruna, Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO) [data set], https://www.irf.se/alis/allsky/krn/ (last access: 11 April 2023), 2023b.
Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO): Geomagnetic field data, Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO) [data set], https://www.irf.se/maggraphs/iaga (last access: 11 April 2023), 2023c.
Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO): Auroral index, Swedish Institute of Space Physics Kiruna Atmospheric and Geophysical
Observatory (IRF-KAGO) [data set], https://www.irf.se/alis/allsky/nowcast/ (last access: 11 April 2023), 2023d.
Syrjäsuo, M. T., Pulkkinen, T. I., Janhunen, P., Viljanen, A., Pellinen, R. J., Kauristie, K., Opgenoorth, H. J., Wallman, S., Eglitis, P., Karlsson, P., Amm, O., Nielsen, E., and Thomas, C.: Observations of substorm electrodynamics using the MIRACLE network, in: Substorms-4, edited by: Kokubun S. and Kamide, Y., Terra Scientific Publishing Company, Tokyo, 111–114, ISBN 0-7923-5465-6, 1998.
Toyomasu, S., Futaana, Y., Yamauchi, M., and S. Maartensson, S.: Low cost
webcast system of real-time all-sky auroral images and MPEG archiving in Kiruna, in: Proceeding of 33rd Annual European Meeting on Atmospheric Studies by Optical Methods, IRF Sci. Rep. 292, 75–84, ISBN 978-91-977255-1-4,
https://www.irf.se/publications/proc33AM/toyomasu-etal.pdf (last access: 11 April 2023), 2008.
a
WDC – World data center: Real-time AE,
https://wdc.kugi.kyoto-u.ac.jp/ae_realtime/presentmonth/index.html (last access: 11 April 2023), 2022.
Yamauchi, M., Brandstrom, U., van Dijk, D., Sergienko, T., and Kero, J.: Improving nowcast capability through automatic processing of combined ground-based measurements, in: Geophys. Res. Abstracts, 20, EGU
General Assembly 2018, 12 April 2018, p. 1779, EGU2018-1779, 2018. a
Short summary
Potential users of all-sky aurora images even include power companies, tourists, and aurora enthusiasts. However, these potential users are normally not familiar with interpreting these images. To make them comprehensive for more users, we developed an automatic evaluation system of auroral activity level. The method involves two steps: first making a simple set of numbers that describes the auroral activity and then further simplifying them into several levels (Level 6 is an auroral explosion).
Potential users of all-sky aurora images even include power companies, tourists, and aurora...