Blar i Department of Physics and Technology på tidsskrift "Journal of Geophysical Research (JGR): Space Physics"

Viser treff 21-40 av 79

    • Effect of ICME-Driven Storms on Field-Aligned and Ionospheric Currents From AMPERE and SuperMAG 

      Pedersen, M.N.; Vanhamäki, H.; Aikio, A.T.; Waters, C.L.; Gjerløv, Jesper; Käki, S.; Workayehu, A.B. (Journal article; Peer reviewed, 2022)
      This study investigates the field-aligned currents (FACs) and ionospheric equivalent currents for interplanetary coronal mass ejection (ICME)-driven storms by considering 45 events with a minimum Dst ≤ −50 nT. The FACs and ...

    • Electrojet Estimates From Mesospheric Magnetic Field Measurements 

      Laundal, Karl Magnus; Yee, J.H.; Merkin, V.G.; Gjerløv, Jesper; Vanhamäki, H.; Reistad, Jone Peter; Madelaire, Michael; Sorathia, K.; Espy, Patrick Joseph (Journal article; Peer reviewed, 2021)
      The auroral electrojet is traditionally measured remotely with magnetometers on ground or in low Earth orbit (LEO). The sparse distribution of measurements, combined with a vertical distance of some 100 km to ground and ...

    • Electron Acceleration and Thermalization at Magnetotail Separatrices 

      Norgren, Astrid Elisabet Cecilia; Hesse, Michael; Graham, Daniel B.; Khotyaintsev, Yuri V.; Tenfjord, Paul; Vaivads, Andris; Steinvall, Konrad; Xu, Yin; Gershman, Daniel J; Lindqvist, Per-Arne; Plaschke, Ferdinand; Burch, James L (Journal article; Peer reviewed, 2020)
      In this study we use the Magnetospheric Multiscale mission to investigate the electron acceleration and thermalization occurring along the magnetic reconnection separatrices in the magnetotail. We find that initially cold ...

    • Evolution of IMF By Induced Asymmetries: The Role of Tail Reconnection 

      Ohma, Anders; Østgaard, Nikolai; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Tenfjord, Paul Arne Riksheim (Journal article; Peer reviewed, 2021)
      North-south asymmetries arise in the magnetosphere-ionosphere system when a significant east-west (By) component is present in the interplanetary magnetic field (IMF). During such conditions, a By component with the same ...

    • Field-Aligned and Ionospheric Currents by AMPERE and SuperMAG During HSS/SIR-Driven Storms 

      Pedersen, M.N.; Vanhamäki, H.; Aikio, A.T.; Käki, S.; Workayehu, A.B.; Waters, C.L.; Gjerløv, Jesper (Journal article; Peer reviewed, 2021)
      This study considers 28 geomagnetic storms with Dst $\leq-50$ nT driven by high-speed streams (HSSs) and associated stream interaction regions (SIRs) during 2010-2017. Their impact on ionospheric horizontal and field-aligned ...

    • First 10 Months of TGF Observations by ASIM 

      Østgaard, Nikolai; Neubert, Torsten; Reglero, Victor; Ullaland, Kjetil; Yang, Shiming; Genov, Georgi; Marisaldi, Martino; Mezentsev, Andrey; Kochkin, Pavlo; Lehtinen, Nikolai; Sarria, David; Qureshi, Bilal Hasan; Solberg, Arne Olav; Maiorana, Carolina; Albrechtsen, Kjetil; Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Christiansen, Freddy; Chanrion, Olivier; Heumesser, Matthias; Navarro-Gonzalez, Javier; Connell, Paul H.; Eyles, Christopher J; Christian, Hugh J.; Al-Nussirat, Samer (Peer reviewed; Journal article, 2019)
      The Atmosphere‐Space Interactions Monitor (ASIM) was launched to the International Space Station on 2 April 2018. The ASIM payload consists of two main instruments, the Modular X‐ray and Gamma‐ray Sensor (MXGS) for imaging ...

    • Gamma Ray Glow Observations at 20-km Altitude 

      Østgaard, Nikolai; Christian, Hugh J.; Grove, J. Eric; Sarria, David; Mezentsev, Andrey; Kochkin, Pavlo; Lehtinen, Nikolai; Quick, Mason; Al-Nussirat, Samer; Wulf, Eric; Genov, Georgi; Ullaland, Kjetil; Marisaldi, Martino; Yang, Shiming; Blakeslee, Richard J. (Peer reviewed; Journal article, 2019)
      In the spring of 2017 an ER‐2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted of a suite of instruments designed to ...

    • A Generalized Method for Calculating Atmospheric Ionization by Energetic Electron Precipitation 

      Xu, Wei; Marshall, Robert A.; Tyssøy, Hilde Nesse; Fang, Xiaohua (Journal article; Peer reviewed, 2020)
      Accurate specification of ionization production by energetic electron precipitation is critical for atmospheric chemistry models to assess the resultant atmospheric effects. Recent model-observation comparison studies have ...

    • Global Dynamical Network of the Spatially Correlated Pc2 Wave Response for the 2015 St. Patrick's Day Storm 

      Chaudhry, S.; Chapman, Sandra; Gjerløv, Jesper; Beggan, C. D. (Journal article; Peer reviewed, 2023)
      We show the global dynamics of spatial correlation of Pc2 wave activity can track the evolution of the 2015 St. Patrick's Day geomagnetic storm for an 8 hr time window around onset. The global spatially coherent response ...

    • Global ULF Waves Excited by Solar Wind Dynamic Pressure Impulses: 1. Timescales and Geomagnetic Activity Dependence 

      Xie, Zi-Kang; Zong, Q.G.; Ren, Jie; Yue, Chao; Liu, Zhi-Yang; Liu, Jian-Jun; Hu, Ze-Jun; Li, Xing-Yu; Yin, Ze-Fan; Yan, Yun; Li, Li; Gjerløv, Jesper (Journal article; Peer reviewed, 2023)
      Solar wind dynamic pressure pulse is one of the sources of ultra-low frequency (ULF) waves. Based on 1-second resolution magnetic field observations from SuperMAG from 2012 to 2019, we conducted a statistical study on ...

    • GPS Scintillations and TEC Variations in Association With a Polar Cap Arc 

      Wang, Yong; Cao, Zheng; Xing, Zan-Yang; Zhang, Qing-He; Jayachandran, P.T.; Oksavik, Kjellmar; Balan, Nanan; Shiokawa, Kazuo (Journal article; Peer reviewed, 2021)
      A unique example of a polar cap arc producing clear amplitude and phase scintillations in GPS L-band signals is presented using observations from an all-sky imager and a GPS receiver and a digital ionosonde at Resolute Bay ...

    • Heavy Metal and Rock in Space: Cluster RAPID Observations of Fe and Si 

      Håland, Stein Egil; Daly, Patrick W.; Vilenius, Esa (Journal article; Peer reviewed, 2021)
      Metallic and silicate ions carry essential information about the evolution of the Earth and near-Earth small bodies. Despite this, there has so far been very little focus on ions with atomic masses higher than oxygen in ...

    • HEPPA III Intercomparison Experiment on Electron Precipitation Impacts: 1. Estimated Ionization Rates During a Geomagnetic Active Period in April 2010 

      Tyssøy, Hilde Nesse; Sinnhuber, M.; Asikainen, T.; Bender, Stefan; Clilverd, M.A.; Funke, B.; van de Kamp, M.; Pettit, J.M.; Randall, C.E.; Reddmann, T.; Rodger, C.J.; Rozanov, E.; Smith-Johnsen, Christine; Sukhodolov, T.; Verronen, P.T.; Wissing, J.M.; Yakovchuk, O. (Journal article; Peer reviewed, 2022)
      Precipitating auroral and radiation belt electrons are considered an important part of the natural forcing of the climate system. Recent studies suggest that this forcing is underestimated in current chemistryclimate models. ...

    • Heppa III Intercomparison Experiment on Electron Precipitation Impacts: 2. Model-Measurement Intercomparison of Nitric Oxide (NO) During a Geomagnetic Storm in April 2010 

      Sinnhuber, M.; Tyssøy, Hilde Nesse; Asikainen, T.; Bender, Stefan; Funke, B.; Hendrickx, K.; Pettit, J.M.; Reddmann, T.; Rozanov, E.; Schmidt, H.; Smith-Johnsen, Christine; Sukhodolov, T.; Szeląg, M.E.; van de Kamp, de; Verronen, P.T.; Wissing, J.M.; Yakovchuk, O.S. (Journal article; Peer reviewed, 2022)
      Precipitating auroral and radiation belt electrons are considered to play an important part in the natural forcing of the middle atmosphere with a possible impact on the climate system. Recent studies suggest that this ...

    • High‐density magnetospheric He+ at the dayside magnetopause and its effect on magnetic reconnection 

      Fuselier, Stephen A.; Haaland, Stein; Tenfjord, Paul; Paschmann, G; Toledo-Redondo, S; Malaspina, D; Kim, M.J.; Trattner, K.J.; Petrinec, S. M.; Giles, B. L.; Goldstein, J; Burch, J. L.; Strangeway, R. J. (Journal article; Peer reviewed, 2021)
      Observations from the Magnetospheric Multiscale (MMS) mission are used to quantify the maximum effect of magnetospheric H+ and He+ on dayside magnetopause reconnection. A data base of current-sheet crossings from the first ...

    • High‐density O+ in Earth's outer magnetosphere and its effect on dayside magnetopause magnetic reconnection 

      Fuselier, SA; Mukherjee, J; Denton, MH; Petrinec, SM; Trattner, K.J.; Toledo-Redondo, S; Andre, M; Aunai, N; Chappell, Charles Richard; Glocer, Alex; Haaland, S.; Hesse, Michael; Kistler, LM; Lavraud, B; Li, WY; Moore, T. E.; Graham, D; Tenfjord, Paul; Dargent, J.; Vines, Sarah K.; Strangeway, Robert J.; Burch, J. L. (Journal article; Peer reviewed, 2019)
      The warm plasma cloak is a source of magnetospheric plasma that contain significant O+. When the O+ density in the magnetosphere near the magnetopause is >0.2 cm‐3 and the H+ density is <1.5 cm‐3, then O+ dominates the ...

    • Inferring source properties of monoenergetic electron precipitation from kappa and Maxwellian moment‐voltage relationships 

      Hatch, Spencer Mark; LaBelle, James; Chaston, C. C. (Peer reviewed; Journal article, 2019)

    • Influence of Off-Sun-Earth Line Distance on the Accuracy of L1 Solar Wind Monitoring 

      Milan, Stephen Eric; Carter, J.A.; Bower, G.E.; Fleetham, A.L.; Anderson, B.J. (Journal article; Peer reviewed, 2022)
      Upstream solar wind measurements from near the L1 Lagrangian point are commonly used to investigate solar wind-magnetosphere coupling. The off-Sun-Earth line distance of such solar wind monitors can be large, up to 100 RE. ...

    • Interaction of Cold Streaming Protons with the Reconnection Process 

      Tenfjord, Paul; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Spinnangr, Susanne Flø; Kolstø, Håkon Midthun; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2020)
      We employ a 2.5D particle-in-cell simulation to study a scenario where the reconnection process captures cold streaming protons. As soon as the tailward streaming protons become involved, they contribute to the overall ...

    • Intercomparison of the POES/MEPED Loss Cone Electron Fluxes With the CMIP6 Parametrization 

      Tyssøy, Hilde Nesse; Haderlein, Astrid; Sandanger, Marit Irene J.; Stadsnes, Johan (Peer reviewed; Journal article, 2019)
      Quantitative measurements of medium energy electron (MEE) precipitation (>40 keV) are a key to understand the total effect of particle precipitation on the atmosphere. The Medium Energy Proton and Electron Detector (MEPED) ...