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Nikolai Østgaard's picture

Nikolai Østgaard

Professor, Leader of Birkeland Centre for Space Science
  • E-mailnikolai.ostgaard@uib.no
  • Phone+47 55 58 27 94
  • Visitor Address
    Allegt 55
    5007 Bergen
    Room 
    446
  • Postal Address
    Postboks 7803
    5020 Bergen
Academic lecture
  • Show author(s) (2019). Observations of Asymmetric Lobe Convection for Weak and Strong Tail Reconnection.
  • Show author(s) (2019). How asymmetries in Geospace evolve during increased tail reconnection.
  • Show author(s) (2019). How Asymmetries in Geospace Evolve During Substorms.
  • Show author(s) (2019). Cluster EDI Observations of the Asymmetric Plasma Convection in the Magnetotail Lobes During Different Levels of Tail Reconnection Rate .
  • Show author(s) (2019). A new way to identify and quantify the sources of ionospheric convection.
  • Show author(s) (2018). Plasma circulation inside the polar cap and lobe reconnection.
  • Show author(s) (2017). The roles of IMF By, dipole tilt, and conductance differences in establishing nonconjugate auroral features.
  • Show author(s) (2017). The influence of plasma flows bringing the magnetotail back to a more symmetric configuration.
  • Show author(s) (2017). Seasonal and IMF-controlled variations in the large-scale true horizontal ionospheric current.
  • Show author(s) (2017). Norwegian contributions to the ISWI program.
  • Show author(s) (2017). Norwegian contributions to SCOSTEP/VarSITI.
  • Show author(s) (2017). North-south asymmetries in lobe density: Cluster observations.
  • Show author(s) (2017). North-South asymmetries in cold plasma density.
  • Show author(s) (2017). Looking South for the Northern Lights:Substorm Physics as University Curriculum.
  • Show author(s) (2017). How the IMF By induces a By-component on closed field lines during northward IMF Bz.
  • Show author(s) (2017). Does the Magnetosphere go to Sleep?
  • Show author(s) (2017). Dayside and nightside magnetic field responses at 780 km altitude to dayside reconnection.
  • Show author(s) (2017). Conjugate auroral imaging: How asymmetric can geospace be ? Magnetic storm 17 aug 2001.
  • Show author(s) (2017). A Synergic Approach to the Study of TGFs and Energetic Radiation from Thunderstorms.
  • Show author(s) (2016). Stereo Observations of Terrestrial Gamma-ray Flashes.
  • Show author(s) (2015). VLF sferics associated with TGFs.
  • Show author(s) (2015). The sequence of events in a lightning stroke: terrestrial gamma ray flash, radio signal and optical lightning.
  • Show author(s) (2015). Statistical maps of Birkeland currents from Swarm magnetometer measurements.
  • Show author(s) (2015). Simultaneous observations of optical lightning and terrestrial gamma flash from space and radio signals on ground.
  • Show author(s) (2015). Simultaneous observations of optical lightning and terrestrial gamma flash and radio signals on ground.
  • Show author(s) (2015). Search for relativistic electrons in laboratory discharge experiments.
  • Show author(s) (2015). Search for Terrestrial Electron Beams (TEBs) in SAMPEX data.
  • Show author(s) (2015). On which timescales are By induced in the closed magnetosphere?
  • Show author(s) (2015). Modeling the production and acceleration of runaway electrons in strong inhomogeneous electric fields with GEANT4.
  • Show author(s) (2015). Magnetic field patterns near the polar cap boundary.
  • Show author(s) (2015). How is Earth coupled to space?
  • Show author(s) (2015). Generation of Birkeland Currents during IMF By; Mechanisms and theory.
  • Show author(s) (2015). Effects of electric field component representation on estimated cross polar cap potential - Implications for interhemispheric asymmetries.
  • Show author(s) (2015). Effects of electric field component representation on estimated cross polar cap potential - Implications for interhemispheric asymmetries.
  • Show author(s) (2015). Dimension of a fractal streamer structure.
  • Show author(s) (2015). Current systems associated with Non-Conjugate Aurora.
  • Show author(s) (2015). Are there auroral signatures related to asymmetric generation of field-aligned currents in the tail due to an IMF By induced twist?
  • Show author(s) (2015). An observation of a TGF from the convective core of a thundercloud.
  • Show author(s) (2014). Twelve Years of RHESSI TGFs - The second RHESSI TGF catalog.
  • Show author(s) (2014). Toward an optimized Third Catalog of RHESSI TGFs.
  • Show author(s) (2014). TGF observations.
  • Show author(s) (2014). Search for X-rays and relativistic electrons in laboratory discharge experiments.
  • Show author(s) (2014). Search for X-rays and relativistic electrons in laboratory discharge experiments.
  • Show author(s) (2014). Search for Terrestrial Electron Beams (TEB) in SAMPEX data.
  • Show author(s) (2014). Recent Results from ADELE and RHESSI.
  • Show author(s) (2014). On the spatial scale of streamers.
  • Show author(s) (2014). On the Spatial Scale of Streamers.
  • Show author(s) (2014). Modelling the runaway electron avalanche and the feedback mechanism with GEANT4.
  • Show author(s) (2014). Lightning activity and radar for a TGF case in Colombia.
  • Show author(s) (2014). Hemispheric differences in solar wind – magnetosphere interactions.
  • Show author(s) (2014). First simultaneous observations of optical lightning and terrestrial gamma flash from space.
  • Show author(s) (2014). Dynamics of a streamer structure.
  • Show author(s) (2014). Conjugate and non-conjugate aspects of the aurora.
  • Show author(s) (2014). Comparison of solar wind driving of the aurora in the two hemispheres due to the solar wind dynamo.
  • Show author(s) (2014). Comparison of solar wind driving of the aurora in the two hemispheres due to solar wind dynamo.
  • Show author(s) (2014). Birkeland Centre for Space Science.
  • Show author(s) (2014). Asymmetric Solar Wind dynamo efficiency and IMF Bx.
  • Show author(s) (2014). An altitude and distance correction to the initial fluence distribution of TGF.
  • Show author(s) (2014). A study of the runaway relativistic electron avalanche and the feedback theory using GEANT4.
  • Show author(s) (2013). What are the mechanisms that produce auroral asymmetries in the conjugate hemispheres?
  • Show author(s) (2013). Unusual bright TGF from low cloud tops over the Mediterranean sea.
  • Show author(s) (2013). UV and X-ray imaging of aurora and other atmospheric phenomena.
  • Show author(s) (2013). Terrestrial gamma ray flashes, the most energetic photon phenomenon in our atmosphere.
  • Show author(s) (2013). Terrestrial gamma ray flashes, the most energetic photon phenomenon in our atmosphere.
  • Show author(s) (2013). Terrestrial Gamma-ray Flashes - the most energetic photon phenomenon in our atmosphere.
  • Show author(s) (2013). Terrestrial Gamma-ray Flashes - the most energetic photon phenomenon in our atmosphere.
  • Show author(s) (2013). Terrestrial Gamma ray Flashes observed over low clod tops.
  • Show author(s) (2013). Terrestrial Gamma ray Flashes observed over low clod tops.
  • Show author(s) (2013). Spatial Correlations and Distributions in Energetic Electron Production by Meter­Scale Sparks.
  • Show author(s) (2013). Simultaneous global imaging as a tracer of true conjugate regions.
  • Show author(s) (2013). Scientific Programme of Birkeland Centre in Space Physics.
  • Show author(s) (2013). Results from the third RHESSI catalog of Terrestrial Gamma-ray Flashes.
  • Show author(s) (2013). Recent Results from ADELE and RHESSI.
  • Show author(s) (2013). Nye fenomener i romforskning - gammaglimt, blå jetter og røde ånder.
  • Show author(s) (2013). Non-Conjugate Features in the Auroral Ovals in the two Hemispheres.
  • Show author(s) (2013). Investigation of the role of IMF Bx on magnetopause characteristic past the terminator.
  • Show author(s) (2013). Investigation of a possible IMF Bx influence on magnetopause characteristics.
  • Show author(s) (2013). Investigation of a possible IMF Bx influence on magnetopause characteristic.
  • Show author(s) (2013). Inter-hemispheric currents in the ring current region.
  • Show author(s) (2013). Intensity of Lightning Associated with TGFs.
  • Show author(s) (2013). Intensity asymmetries between the northern and southern auroral ovals associated with the x-component of the Interplanetary Magnetic Field.
  • Show author(s) (2013). First simultaneous observations of optical lightning and terrestrial gamma flash from space.
  • Show author(s) (2013). Defining and Resolving Current Systems in Geospace.
  • Show author(s) (2013). A study of the relativistiv runaway electron avalanche and the feedback theories to explain terrestrial gammaray production.
  • Show author(s) (2011). The true distribution of TGF fluence measured from space.
  • Show author(s) (2011). The global auroral response to solar wind - Earth magnetosphere coupling.
  • Show author(s) (2011). The frequency of terrestrial gamma-ray flash electron beam observations.
  • Show author(s) (2011). The TGF source luminosity distribution.
  • Show author(s) (2011). Terrestrial Gamma-ray Flash Intensity Distribution.
  • Show author(s) (2011). Terrestrial Gamma-Ray Flash Intensity Distribution.
  • Show author(s) (2011). TGF dependence on magnetic latitude and solar zenith angle.
  • Show author(s) (2011). Statistics of Plasma Sheet Convection.
  • Show author(s) (2011). Particle Acceleration During Solar Flares and Magnetospheric Substorms.
  • Show author(s) (2011). Occurence frequency and fluence of TGFs.
  • Show author(s) (2011). Occurence frequency and fluence of TGFs.
  • Show author(s) (2011). Modeling TGF electron beams and constraints on the TGF source.
  • Show author(s) (2011). Imapct of recent results About TGFs and TLEs to the scientific return OF the cobrat project.
  • Show author(s) (2011). Flux cloaure during magnetotail reconnection.
  • Show author(s) (2011). Determination of polar cap size and shape using energetic particles.
  • Show author(s) (2011). Constrains on the Terrestrial Gamma-ray Flashes Emission Cone by Spectral Analysis of Geolocated Events. EGU.
  • Show author(s) (2011). Confining the angular distribution of TGF emission.
  • Show author(s) (2011). Auroral asymmetries in the conjugate hemispheres during substorm onset and expansion phase.
  • Show author(s) (2011). Auroral asymmetries in the conjugate hemispheres.
  • Show author(s) (2011). Auroral asymmetries in the conjugate hemispheres.
  • Show author(s) (2011). Auroral asymmetries in the conjugate hemispheres.
  • Show author(s) (2011). Asymmetries of substorm onset location and the dynamic behavior of auroral substorms during expansion phase.
  • Show author(s) (2011). Are there more TGFs in the RHESSI data.
  • Show author(s) (2009). The ASIM Mission for Studies of Severe Thunderstorms,.
  • Show author(s) (2009). Substorm auroral asymmetries in the conjugate hemispheres during onset and expansion phase.
  • Show author(s) (2009). Reconnection Hall current system observed in the magnetotail and in the ionosphere.
  • Show author(s) (2009). Production altitude, initial distributions and time delays for TGFs when instrumental deadtime effects are treated properly.
  • Show author(s) (2009). IPY-ICESTAR Arctic Frontiers.
  • Show author(s) (2009). IMF Bx Effects on Interhemispheric Polar Cap Asymmetries Inferred From Conjugate Auroral Imaging.
  • Show author(s) (2009). Go With the Flow: The Reductionist View of Geospace at the System Level.
  • Show author(s) (2009). Conjugate aurora observations of substorms IAGA meeting.
  • Show author(s) (2009). Auroral Small-and Meso-Scale Structures, Origin and Function.
  • Show author(s) (2009). Asymmetric aurora detected in the two hemispheres simultaneously.
  • Show author(s) (2009). Asymmetric aurora detected in the two hemispheres simultaneously.
  • Show author(s) (2009). Asymmetric aurora detected in the two hemispheres simultaneously.
  • Show author(s) (2009). Analysis of a subset of BATSE TGFs that do not suffer from instrumental limitations.
  • Show author(s) (2009). Analysis of BATSE TGFs taking instrumental limitations into account.
  • Show author(s) (2009). An X- and gamma-ray detector for observing terrestrial gamma flashes from the International Space Station.
  • Show author(s) (2008). What are the ionospheric signatures of magnetotail reconnection?
  • Show author(s) (2008). Undulations on the equatorial edge of the auroral oval in the dusk sector.
  • Show author(s) (2008). The production altitude and time delays of the terrestrial gamma flashes - revisiting the BATSE spectra.
  • Show author(s) (2008). The production altitude and time delays of the terrestrial gamma flashes - revisiting the BATSE spectra.
  • Show author(s) (2008). The production altitude and time delays of the terrestrial gamma flashes - revisiting the BATSE spectra.
  • Show author(s) (2008). The Space Science Suitcase Instruments for Exploring Space Weather From the Classroom.
  • Show author(s) (2008). Observations of energetic particle precipitation and effects on the mesosphere and lower thermosphere.
  • Show author(s) (2008). Monte Carlo simulation of the temporal behavior of Terrestrial Gamma ray Flashes and analysis of the BATSE measurements.
  • Show author(s) (2008). Monte Carlo simulation of the temporal behavior of Terrestrial Gamma ray Flashes.
  • Show author(s) (2008). Conjugate observations of substorm onset and expansion in the two hemispheres.
  • Show author(s) (2008). Conjugate imaging of substorms.
  • Show author(s) (2008). Auroral conjugacy studies.
  • Show author(s) (2008). Analysis of a subset of BATSE TGFs that do not suffer from instrumental limitations.
  • Show author(s) (2007). olar System X-rays: Relationship with Solar X-rays and Solar Wind.
  • Show author(s) (2007). What are the ionospheric signatures of magnetotail reconnection?
  • Show author(s) (2007). What are the ionospheric signatures of magnetotail reconnection?
  • Show author(s) (2007). The Spce Suitcase - instruments for exploring the near-Earth space from the classroom.
  • Show author(s) (2007). Solar wind pressure as a cause for persistent proton precipitation.
  • Show author(s) (2007). Monte Carlo simulation of the temporal behavior of Terrestrial Gamma ray Flashes.
  • Show author(s) (2007). IPY-ICESTAR.
  • Show author(s) (2007). ESA's Atmosphere-Space Interactions Monitor (ASIM) for the ISS.
  • Show author(s) (2007). Conjugate studies.
  • Show author(s) (2007). Conjugate studies.
  • Show author(s) (2007). ASIM.
  • Show author(s) (2006). X-ray spectra measured by MXGS can reveal the production altitude of TGFs.
  • Show author(s) (2006). The Atmosphere-Space Interactions Monitor (ASIM) for the International Space Station.
  • Show author(s) (2006). TGF production altitude - revisiting the BATSE spectra in view of upcoming missions.
  • Show author(s) (2006). Substorm onset asymmetries derived from conjugate auroral imaging.
  • Show author(s) (2006). Simulaneous imaging of the reconnection spot in the opposite hemispheres during northward IMF.
  • Show author(s) (2006). Satellite remote mapping of the precipitation of energetic electrons and their effects on the Earth's upper atmosphere.
  • Show author(s) (2006). Remote sensing of X rays to study characteristics of electron precipitation.
  • Show author(s) (2006). Imaging the upper atmopshere from space.
  • Show author(s) (2006). ICESTAR: Auroral conjugacy studies.
  • Show author(s) (2006). ICESTAR A connection between IHY and IPY.
  • Show author(s) (2006). Hemispherical asymmetries derived from conjugate auroral imaging.
  • Show author(s) (2006). Global observations of the dynamics of energetic electron precipitation during substorms.
  • Show author(s) (2006). Global imaging to predict space weather.
  • Show author(s) (2006). Conjugate imaging of substorms.
  • Show author(s) (2006). Auroral conjugacy studies based on global imaging.
  • Show author(s) (2006). Auroral conjugacy studies.
  • Show author(s) (2005). Studies of an X-line passage 2 October 2002 using multipoint Cluster and Polar imaging data,.
  • Show author(s) (2005). Production altitude effects on the X-ray spectrum from TGFs.
  • Show author(s) (2005). Production altitude effects on the X-ray spectrum from TGFs.
  • Show author(s) (2005). Kjemiske effekter av elektronnedbør i den lavere termosfæren.
  • Show author(s) (2005). Ionospheric global conductance maps from remote sensing of UV and X-ray emissions.
  • Show author(s) (2005). Height profiles of the ionospheric electron density derived from remote sensing of UV- and X-ray emissions and measured by EISCAT radar.
  • Show author(s) (2005). Height profiles of the ionospheric electron density derived from remote sensing of UV and X-ray emissions and measurements by the EISCAT radar: A comparison.
  • Show author(s) (2005). Global imaging of Auroral Phenomena in the Conjugate Hemispheres.
  • Show author(s) (2005). Effects on the O/N2-ratio caused by ionospheric heating during geomagnetic storms.
  • Show author(s) (2005). Conjugate auroral observations, Now and in the future.
  • Show author(s) (2005). Chemical effects of electron precipitation: Nitric Oxide in the lower thermosphere.
  • Show author(s) (2005). Auroral signatures of lobe reconnection observed simultaneously in the conjugate hemispheres.
  • Show author(s) (2005). A double spacecraft imaging mission to study reconnection and ion outflow.
  • Show author(s) (2005). A Comparative View of X-rays from the Solar System.
  • Show author(s) (2004). The impact of energetic electron precipitation on nitric oxide in the upper atmosphere - Including neutral wind effects.
  • Show author(s) (2004). The combination of auroral imaging and spacecraft in-situ measurements for M-I coupling research.
  • Show author(s) (2004). Sub-Auroral Morning Proton Spots (SAMPS) as a result of plasmapause-ring-current interaction.
  • Show author(s) (2004). Simultaneous observations of the auroral oval in both hemispheres under various conditions.
  • Show author(s) (2004). Seasonal dependence of localized, High Latitude Dayside Aurora (HiLDA).
  • Show author(s) (2004). Response of magnetospheric electric fields and dayside auroras to a solar wind pressure pulse.
  • Show author(s) (2004). Response of dayside auroras and ionospheric plasma flows to a solar wind pressure pulse.
  • Show author(s) (2004). Observations and analysis of ionospheric electrodynamics during a substorm recovery phase using the MIRACLE network.
  • Show author(s) (2004). IMF control of the aurora in the conjugate hemispheres.
  • Show author(s) (2004). IMF control of auroral phenomena in the conjugate hemispheres.
  • Show author(s) (2004). IMAGE-FUV observations of the October-November 2003 flare and magnetic storm effects on Earth.
  • Show author(s) (2004). First terrestrial soft X-ray aurora observations by Chandra.
  • Show author(s) (2004). Electric and magnetic field and particle observations on Cluster combined with ground-based observations during substorms.
  • Show author(s) (2004). Effects on the O/N2-ratio caused by energetic electron precipitation during storms.
  • Show author(s) (2004). Chandra observations of soft X-ray emissions from Earth and Jupiter.
  • Show author(s) (2000). Temporal and Spatial Features of the Energetic Electron Precipitation During Substroms.
  • Show author(s) (2000). Temporal and Spatial Features of the Energetic Electron Precipitation During Substorms.
  • Show author(s) (2000). Temporal and Spatial Features of the Energetic Electron Precipitation During Substorms.
  • Show author(s) (2000). Global energy input derived from UVI and PIXIE.
  • Show author(s) (2000). Global energy input derived from UVI and PIXIE.
  • Show author(s) (2000). Global Conductivity Maps Derived From Polar PIXIE Observations.
  • Show author(s) (2000). Energy Analysis of an Isolated Substorm Based on Remote Sensing Techniques.
  • Show author(s) (2000). Energetic Particle Signatures of Reconnection and Plasmoid Formation in the Magnetotail.
  • Show author(s) (2000). Comparison of energy spectra in the ionosphere and in the central plasma sheet during a magnetospheric substorm.

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