Search Results - "Johnsen, Magnar"

An automated auroral detection system using deep learning: real-time operation in Tromsø, Norway by Nanjo, Sota, Nozawa, Satonori, Yamamoto, Masaki, Kawabata, Tetsuya, Johnsen, Magnar G., Tsuda, Takuo T., Hosokawa, Keisuke

“…The activity of citizen scientists who capture images of aurora borealis using digital cameras has recently been contributing to research regarding space…”
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How Often Do Thermally Excited 630.0 nm Emissions Occur in the Polar Ionosphere? by Kwagala, Norah Kaggwa, Oksavik, Kjellmar, Lorentzen, Dag A., Johnsen, Magnar G.

“…This paper studies thermally excited emissions in the polar ionosphere derived from European Incoherent Scatter Svalbard radar measurements from the years…”
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On the contribution of thermal excitation to the total 630.0 nm emissions in the northern cusp ionosphere by Kwagala, Norah Kaggwa, Oksavik, Kjellmar, Lorentzen, Dag A., Johnsen, Magnar G.

“…Direct impact excitation by precipitating electrons is believed to be the main source of 630.0 nm emissions in the cusp ionosphere. However, this paper…”
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Seasonal and Solar Cycle Variations of Thermally Excited 630.0 nm Emissions in the Polar Ionosphere by Kwagala, Norah Kaggwa, Oksavik, Kjellmar, Lorentzen, Dag A., Johnsen, Magnar G., Laundal, Karl M.

“…Solar cycle and seasonal variations have been found in the occurrence of strong thermally excited 630.0 nm emissions in the polar ionosphere. Measurements from…”
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Neurosensory and vascular symptoms and clinical findings in the hands of Arctic open-pit miners in Sweden and Norway – a descriptive study by Stjernbrandt, Albin, Johnsen, Magnar, Liljelind, Ingrid, Aminoff, Anna, Wahlström, Jens, Höper, Anje Christina, Pettersson, Hans, Nilsson, Tohr

“…This cross-sectional study aimed to describe exposure to cold climate and hand-arm vibration (HAV) as well as neurosensory and vascular symptoms and clinical…”
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A statistical study of convective and dynamic instabilities in the polar upper mesosphere above Tromsø by Nozawa, Satonori, Saito, Norihito, Kawahara, Takuya, Wada, Satoshi, Tsuda, Takuo T., Maeda, Sakiho, Takahashi, Toru, Fujiwara, Hitoshi, Narayanan, Viswanathan Lakshmi, Kawabata, Tetsuya, Johnsen, Magnar G.

“…We have studied the convective (or static) and dynamic instabilities between 80 and 100 km above Tromsø (69.6° N, 19.2° E) using temperature and wind data of…”
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High-latitude crochet: solar-flare-induced magnetic disturbance independent from low-latitude crochet by Yamauchi, Masatoshi, Johnsen, Magnar G., Enell, Carl-Fredrik, Tjulin, Anders, Willer, Anna, Sormakov, Dmitry A.

“…A solar-flare-induced, high-latitude (peak at 70–75∘ geographic latitude – GGlat) ionospheric current system was studied. Right after the X9.3 flare on 6…”
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EISCAT Observation of Wave‐Like Fluctuations in Vertical Velocity of Polar Mesospheric Summer Echoes Associated With a Geomagnetic Disturbance by Lee, Young‐Sook, Kim, Yong Ha, Kim, Kyung‐Chan, Kwak, Young‐Sil, Sergienko, Timothy, Kirkwood, Sheila, Johnsen, Magnar G.

“…By analyzing a data set from the European Incoherent SCATter (EISCAT) Very High Frequency (VHF) radar at Tromsø, we find that both radar reflectivity and…”
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Reconstruction of electron precipitation spectra at the top of the upper atmosphere using 427.8 nm auroral images by Robert, Elisa, Barthelemy, Mathieu, Cessateur, Gael, Woelfflé, Angélique, Lamy, Hervé, Bouriat, Simon, Gullikstad Johnsen, Magnar, Brändström, Urban, Biree, Lionel

“…We present an innovative method to reconstruct the characteristics of precipitated electrons in auroral regions from optical measurements. This method is based…”
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The polarisation of auroral emissions: A tracer of the E region ionospheric currents by Bosse, Léo, Lilensten, Jean, Johnsen, Magnar G., Gillet, Nicolas, Rochat, Sylvain, Delboulbé, Alain, Curaba, Stephane, Ogawa, Yasunobu, Derverchère, Philippe, Vauclair, Sébastien

“…It is now established that auroral emissions as measured from the ground are polarised. The question of the information given by this polarisation is still to…”
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Tinnitus and associations with chronic pain: The population-based Tromsø Study (2015-2016) by Ausland, Jannike H-L, Engdahl, Bo, Oftedal, Bente, Steingrímsdóttir, Ólöf A, Nielsen, Christopher S, Hopstock, Laila A, Johnsen, Magnar, Friborg, Oddgeir, Rosenvinge, Jan H, Eggen, Anne E, Krog, Norun H

“…Tinnitus and pain have many similarities. Both are subjective sensations that may turn chronic, they are often accompanied by hypersensitivity in their…”
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Tinnitus and cardiovascular disease: the population-based Tromsø Study (2015–2016) by Ausland, Jannike Heyerdahl-Larsen, Engdahl, Bo, Oftedal, Bente, Hopstock, Laila A, Johnsen, Magnar, Krog, Norun Hjertager

“…IntroductionPeople with tinnitus are likely to have other co-occurring disorders that should be considered when diagnosing and understanding tinnitus as a…”
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On the nightglow polarisation for space weather exploration by Bosse, Léo, Lilensten, Jean, Gillet, Nicolas, Rochat, Sylvain, Delboulbé, Alain, Curaba, Stephane, Roux, Alain, Magnard, Yves, Johnsen, Magnar G., Løvhaug, Unni-Pia, Amblard, Pierre-Olivier, Le Bihan, Nicolas, Nabon, Maxime, Marif, Hanane, Auriol, Frédérique, Noûs, Camille

“…We present here observations of the polarisation of four auroral lines in the auroral oval and in the polar cusp using a new ground polarimeter called Petit…”
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The thermospheric auroral red line Angle of Linear Polarization by Lilensten, Jean, Barthélemy, Mathieu, Besson, Gérard, Lamy, Hervé, Johnsen, Magnar G., Moen, Jøran

“…The auroral red line at 630 nm is linearly polarized. Up to now, only its Degree of Linear Polarization had been studied. In this article, we examine for the…”
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Multiple E-Region Radar Propagation Modes Measured by the VHF SIMONe Norway System During Active Ionospheric Conditions by Huyghebaert, Devin, Clahsen, Matthias, Chau, Jorge L., Renkwitz, Toralf, Latteck, Ralph, Johnsen, Magnar G., Vierinen, Juha

“…Multiple propagation modes between different bistatic radar links were measured during the operations of a very high frequency (VHF) 32.55 MHz radar system in…”
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Exposure to whole-body vibration in open-cast mines in the Barents region by Burström, Lage, Hyvärinen, Ville, Johnsen, Magnar, Pettersson, Hans

“…We aimed to measure and evaluate whole-body vibration (WBV) exposure among drivers of mining vehicles in the Barents region. In the period from November 2012…”
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Science Highlights from the Kjell Henriksen Observatory on Svalbard by Herlingshaw, Katie, Partamies, Noora, van Hazendonk, Charlotte, Syrjäsuo, Mikko, Baddeley, Lisa, Johnsen, Magnar, Eriksen, Nina, McWhirter, Ian, Aruliah, Anasuya, Engebretson, Mark, Oksavik, Kjellmar, Sigernes, Fred, Lorentzen, Dag, Nishiyama, Takanori, Cooper, Matthew, Meriwether, John, Haaland, Stein, Whiter, Daniel

“…The Kjell Henriksen Observatory (KHO) is the world's largest optical observatory for auroral and airglow measurements, operated by the University Centre in…”
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Effects of substorm electrojet on declination along concurrent geomagnetic latitudes in the northern auroral zone by Edvardsen, Inge, Johnsen, Magnar G., Løvhaug, Unni P.

“…The geomagnetic field often experiences large fluctuations, especially at high latitudes in the auroral zones. We have found, using simulations, that there are…”
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Real-time determination and monitoring of the auroral electrojet boundaries by Johnsen, Magnar Gullikstad

“…A method for nowcasting of the auroral electrojet location from real-time geomagnetic data in the European sector is presented. Along the auroral ovals strong…”
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Measurement of the polarisation in the auroral N2+ 427.8 nm band by Barthelemy, Mathieu, Lamy, Hervé, Vialatte, Anne, Magnar Gullikstad Johnsen, Cessateur, Gaël, Zaourar, Naïma

“…In this paper, we provide for the first time polarisation measurements of the N+2 band at 427.8 nm performed with Premier Cru, a dedicated spectropolarimeter…”
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