Search Results - "Ostgaard, N"

Energy transfer and flow in the solar wind-magnetosphere-ionosphere system: A new coupling function by Tenfjord, P., Østgaard, N.

“…In this paper we describe and quantify the energy transfer, flow, and distribution. Our high‐resolution data set covers 13 years of OMNI, SuperMAG, and Kyoto…”
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Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres by Laundal, K. M, Østgaard, N

“…It is commonly assumed that the aurora borealis (Northern Hemisphere) and aurora australis (Southern Hemisphere) are mirror images of each other because the…”
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How the IMF B y induces a B y component in the closed magnetosphere and how it leads to asymmetric currents and convection patterns in the two hemispheres by Tenfjord, P., Østgaard, N., Snekvik, K., Laundal, K. M., Reistad, J. P., Haaland, S., Milan, S. E.

“…Abstract We used the Lyon‐Fedder‐Mobarry global magnetohydrodynamics model to study the effects of the interplanetary magnetic field (IMF) B y component on the…”
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Overview of Solar Wind–Magnetosphere–Ionosphere–Atmosphere Coupling and the Generation of Magnetospheric Currents by Milan, S. E., Clausen, L. B. N., Coxon, J. C., Carter, J. A., Walach, M.-T., Laundal, K., Østgaard, N., Tenfjord, P., Reistad, J., Snekvik, K., Korth, H., Anderson, B. J.

“…We review the morphology and dynamics of the electrical current systems of the terrestrial magnetosphere and ionosphere. Observations from the Active…”
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Enhanced detection of terrestrial gamma-ray flashes by AGILE by Marisaldi, M., Argan, A., Ursi, A., Gjesteland, T., Fuschino, F., Labanti, C., Galli, M., Tavani, M., Pittori, C., Verrecchia, F., D'Amico, F., Østgaard, N., Mereghetti, S., Campana, R., Cattaneo, P.W., Bulgarelli, A., Colafrancesco, S., Dietrich, S., Longo, F., Gianotti, F., Giommi, P., Rappoldi, A., Trifoglio, M., Trois, A.

“…At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable…”
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Statistics of plasma sheet convection by Juusola, L., Østgaard, N., Tanskanen, E.

“…Determining the characteristics of plasma sheet convection and their response to changes in various solar wind parameters is important for understanding the…”
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Quantifying the Lobe Reconnection Rate During Dominant IMF B y Periods and Different Dipole Tilt Orientations by Reistad, J. P., Laundal, K. M., Østgaard, N., Ohma, A., Burrell, A. G., Hatch, S. M., Haaland, S., Thomas, E. G.

“…Abstract Lobe reconnection is usually thought to play an important role in geospace dynamics only when the Interplanetary Magnetic Field (IMF) is mainly…”
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Evolution of IMF B y Induced Asymmetries: The Role of Tail Reconnection by Ohma, A., Østgaard, N., Laundal, K. M., Reistad, J. P., Hatch, S. M., Tenfjord, P.

“…Abstract North‐south asymmetries arise in the magnetosphere‐ionosphere system when a significant east‐west ( B y ) component is present in the interplanetary…”
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How the IMF B y Induces a Local B y Component During Northward IMF B z and Characteristic Timescales by Tenfjord, P., Østgaard, N., Haaland, S., Snekvik, K., Laundal, K. M., Reistad, J. P., Strangeway, R., Milan, S. E., Hesse, M., Ohma, A.

“…Abstract We use the Lyon‐Fedder‐Mobarry global magnetohydrodynamics model to study the effects of the interplanetary magnetic field (IMF) B y component on the…”
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Birkeland current effects on high-latitude ground magnetic field perturbations by Laundal, K. M., Haaland, S. E., Lehtinen, N., Gjerloev, J. W., Østgaard, N., Tenfjord, P., Reistad, J. P., Snekvik, K., Milan, S. E., Ohtani, S., Anderson, B. J.

“…Magnetic perturbations on ground at high latitudes are directly associated only with the divergence‐free component of the height‐integrated horizontal…”
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Relativistic electrons from sparks in the laboratory by Østgaard, N., Carlson, B. E., Nisi, R. S., Gjesteland, T., Grøndahl, Ø., Skeltved, A., Lehtinen, N. G., Mezentsev, A., Marisaldi, M., Kochkin, P.

“…Discharge experiments were carried out at the Eindhoven University of Technology in 2013. The experimental setup was designed to search for electrons produced…”
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A new population of terrestrial gamma‐ray flashes in the RHESSI data by Østgaard, N., Albrecthsen, K. H., Gjesteland, T., Collier, A.

“…Terrestrial gamma‐ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these…”
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Magnetospheric response and reconfiguration times following IMF B y reversals by Tenfjord, P., Østgaard, N., Strangeway, R., Haaland, S., Snekvik, K., Laundal, K. M., Reistad, J. P., Milan, S. E.

“…Abstract The interaction between the interplanetary magnetic field (IMF) and the geomagnetic field at the dayside magnetopause leads to transfer of momentum…”
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Interplanetary Magnetic Field B x Component Influence on Horizontal and Field‐Aligned Currents in the Ionosphere by Laundal, K. M., Reistad, J. P., Finlay, C. C., Østgaard, N., Tenfjord, P., Snekvik, K., Ohma, A.

“…Abstract Statistical analyses have shown that the sunward component of the interplanetary magnetic field, B x (Geocentric Solar Magnetospheric), moderately but…”
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North‐south asymmetries in cold plasma density in the magnetotail lobes: Cluster observations by Haaland, S., Lybekk, B., Maes, L., Laundal, K., Pedersen, A., Tenfjord, P., Ohma, A., Østgaard, N., Reistad, J., Snekvik, K.

“…In this paper, we present observations of cold (0–70 eV) plasma density in the magnetotail lobes. The observations and results are based on 16 years of Cluster…”
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Library of Simulated Gamma‐Ray Glows and Application to Previous Airborne Observations by Sarria, D., Østgaard, N., Marisaldi, M., Lehtinen, N., Mezentsev, A.

“…Gamma‐Ray Glows (GRGs) are high energy radiation originating from thunderclouds, in the MeV energy regime, with typical duration of seconds to minutes, and…”
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On the non-conjugacy of nightside aurora and their generator mechanisms by Reistad, J. P., Østgaard, N., Laundal, K. M., Oksavik, K.

“…We have investigated a data set of 19 h of simultaneous global conjugate auroral imaging from space. The data set consists of 10 sequences with durations from…”
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Constraining Spectral Models of a Terrestrial Gamma‐Ray Flash From a Terrestrial Electron Beam Observation by the Atmosphere‐Space Interactions Monitor by Sarria, D., Østgaard, N., Kochkin, P., Lehtinen, N., Mezentsev, A., Marisaldi, M., Lindanger, A., Maiorana, C., Carlson, B. E., Neubert, T., Reglero, V., Ullaland, K., Yang, S., Genov, G., Qureshi, B. H., Budtz‐Jørgensen, C., Kuvvetli, I., Christiansen, F., Chanrion, O., Navarro‐González, J., Connel, P., Eyles, C.

“…Terrestrial Gamma ray Flashes (TGFs) are short flashes of high energy photons, produced by thunderstorms. When interacting with the atmosphere, they produce…”
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Terrestrial gamma-ray flash electron beam geometry, fluence, and detection frequency by Carlson, B. E., Gjesteland, T., Østgaard, N.

“…Terrestrial gamma‐ray flashes (TGFs) are associated with emission of detectable beams of electrons into space. In this paper we use simulations of TGF and…”
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Defining and resolving current systems in geospace by Ganushkina, N. Y., Liemohn, M. W., Dubyagin, S., Daglis, I. A., Dandouras, I., De Zeeuw, D. L., Ebihara, Y., Ilie, R., Katus, R., Kubyshkina, M., Milan, S. E., Ohtani, S., Ostgaard, N., Reistad, J. P., Tenfjord, P., Toffoletto, F., Zaharia, S., Amariutei, O.

“…Electric currents flowing through near-Earth space (R ≤ 12 RE) can support a highly distorted magnetic field topology, changing particle drift paths and…”
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