48) N. Østgaard ,T. Gjesteland, J. Stadsnes, P. H. Connell, B. Carlson. The production
altitude and time delays of the terrestrial gamma flashes - revisiting the BATSE spectra.
J. Geophys. Res., Accepted Sept 2007.
[pdf]
47) C. Sætre , C. A. Barth, J. Stadsnes, N. Østgaard, S. M. Baily,
D. N. Baker, G. A. Germany and J. W. Gjerloev. Thermospheric nitric oxide at higher
latitudes - Model calculations with auroral energy input.
J. Geophys. Res., Vol. 112, No. A8, A08306, doi: 19.1029.2006JA012203, 2007.
[pdf]
46) K. Snekvik, S. Haaland, N. Østgaard, H. Hasegawa, R. Nakamura, T. Takada, F. Pitout,
H. R`eme, B. Klecker, and E. A. Lucek.
Cluster observations of a field aligned current at the dawn
flank of a bursty bulk flow. Ann. Geophys., 25, 1405-1415, 2007.
[pdf]
45) A. L. Borg, N. Østgaard, A. Pedersen M. Øieroset, T. D. Phan, G.
Germany, A. Aasnes, W. Lewis, J. Stadsnes, E. A. Lucek, H. R`eme, C. Moukis. Simultaneous observations of magnetotail
reconnection and bright X-ray aurora on 2. October 2002. J. Geophys. Res.,
Vol. 112, No. A6, A06215, doi: 10.1029/2006JA011913, 2007.
[pdf]
44) Anil Bhardwaj, Ronald F. Elsner, G. Randall Gladstone,
Thomas E. Cravens, Carey M. Lisse, Konrad Dennerl, Graziella Branduardi-Raymont, Brad Wargelin, J. Hunter Waite Jr., Ina Robertson,
Nikolai Østgaard, Peter Beiersdorfer,
Steven L. Snowden,
Vasili Kharchenko. X-rays from Solar System Bodies,
Review paper in Planet Space Science, Vol 55/9, pp 1135-1189, doi: 10.1016/j.pss.2006.11.009, 2007.
[online pdf]
43) N. Østgaard , S. B. Mende, H. U. Frey, J. B. Sigwarth, A. Aasnes, J. Weygand.
Auroral conjugacy studies based on global imaging
J. Atmos. Solar-Terr. Phys., special issue from Yosemite 2006, 69, 249-255, 2007.
[pdf]
42) Anil Bhardwaj , G. Randall Gladstone, Ronald F. Elsner, Nikolai Østgaard, J. Hunter
Waite, Jr., Thomas E. Cravens, Shen-Wu Chang, Tariq Majeed, Albert E. Metzger.
First terrestrial soft X-ray auroral observation by the Chandra X-ray Observatory.
J. Atmos. Solar-Terr. Phys., Vol 69/ 1-2 pp 179-187, DOI: 10.1016/j.jastp.2006.07.011, 2007.
[pdf]
41) C. Sætre , C. A. Barth, J. Stadsnes, N. Østgaard, S. M. Baily,
D. N. Baker and J. W. Gjerloev. Comparison of electron energy deposition calculated
by a photochemical nitric oxide model, and derived
from X.ray bremsstrahlung measurements
J. Geophys. Res., Vol. 111, No. A4, A04301
doi:10.1029/2005JA011399, 2006.
[pdf]
40) A. Aksnes , J. Stadsnes, N. Ostgaard, G. A. Germany, K. Oksavik,
R. R. Vondrak, A. Brekke, U. P. Lovhaug.
Height profiles of the ionospheric electron density derived using
space-based remote sensing of UV and X-ray emissions, and EISCAT radar
data: A ground-truth experiment.
J. Geophys. Res., Vol. 111, No. A2, A02301, doi:10.1029/2005JA011331, 2006.
[pdf]
39) E. Tanskanen, M. Palmroth, T.I. Pulkkinen, H.E.J. Koskinen, P. Janhunen, N. Østgaard, J.A.
Slavin, K. Liou. Energetics of a substorm on 15 august, 2001: comparing empirical methods and a
global MHD simulation.
Advances in Space Research, 36, 10, 1825, 2005.
[pdf]
38) N. Østgaard, S. B. Mende , H. U. Frey , J. B.
Sigwarth. Simultaneous imaging of the reconnection spot in the
conjugate hemispheres during northward IMF.
Highlighted in Geophys. Res. Lett., Vol. 32, No. 21, L21104, doi: 10.1029/2005GL024491, 2005.
[pdf]
37) M. Palmroth , P. Janhunen, T. I. Pulkkinen, A. Aksnes, G. Lu , N. Østgaard,
J. Watermann, G. D. Reeves, G. A. Germany. Assessment of ionospheric Joule heating by
GUMICS-4 MHD simulation, AMIE, and satellite-based statistics:
Towards a synthesis.
Annales Geophysicae, 23, 2051-2068, 2005,
[pdf]
36) A. Åsnes, J. Stadsnes, R. W. Friedel, N. Østgaard, M. Thomsen.
Medium energy pitch anglke distribution during substorm injected electron
cloud.
Geophys. Res. Lett., Vol. 32, No. 10, L10101, doi: 10.1029/2004GL022008, 2005.
[pdf]
35) A. Åsnes, R. W. Friedel, J. Stadsnes, M. Thomsen, N. Østgaard,
T. Cayton. Statistical pitch angle properties of substorm injected electron
clouds and their relation to dawnside energetic electron precipitation.
J. Geophys. Res., Vol. 110, No. A5, A05207, doi:10.1029/2004JA010838, 2005.
[pdf]
34) O. Amm, A. Aksnes, J. Stadsnes, N. Østgaard, R. R. Vondrak, G. A. Germany,
G. Lu, A. Viljanen. Mesoscale ionospheric electrodynamics of omega bands determined
from ground-based electromagnetic and satellite optical observations.
Ann. Geophys., 23 (2): 325-342 2005.
[pdf]
33) A. Aksnes, O. Amm, J. Stadsnes, N. Østgaard, G. A. Germany, R. R. Vondrak,
I. Sillanpaa. Ionospheric conductances derived from satellite measurements
and auroral UV and X-ray emissions, and ground-based electromagnetic data: A
comparison.
Ann. Geophys., 23 (2): 343-358 2005.
[pdf]
32) A. Kozlovsky, V. Safargaleev, N. Østgaard, T. Turunen, J. Jussila, A
Roldugin. On the motion of dayside auroras caused by a solar wind pressure pulse.
Ann. Geophys., 23 (2): 509-521 2005.
[pdf]
31) N. Østgaard, N. A. Tsyganenko, S. B. Mende , H. U. Frey , T. J. Immel, M. Fillingim, L. A. Frank, J. B.
Sigwarth. Observations and model predictions of substorm auroral asymmetries in the
conjugate hemispheres.
Geophys. Res. Lett., 32, 5, L05111, doi:10.1029/2004GL022166, 2005.
[pdf]
30) N. Østgaard, J. Moen, S. B. Mende, H. U. Frey, T. J. Immel, P. Gallop, K.
Oksavik, M. Fujimoto. Estimates of magnetotail reconnection rate based on IMAGE FUV
and EISCAT measurements
Ann. Geophys. (Eleventh International EISCAT Workshop),
23 (1), 123-134, 2005.
[pdf]
29) T. J. Stubbs , R. R. Vondrak and N. Østgaard, J. B. Sigwarth and
L. A. Frank. Simultaneous observations of the auroral oval in both
hemispheres under varying conditions.
Geophys. Res. Lett., Vol 32, L03103, doi:10.1029/2004GL021199, 2005.
[pdf]
28) H.U. Frey , G. Haerendel, S.B. Mende, W. T. Forrester, T.J. Immel, N. Østgaard.
Sub-auroral morning proton spots (SAMPS) as a result of plasmapause-ring current
interaction,
J. Geophys. Res., 109, A10305, 10.1029/2004JA010516, 2004.
[pdf]
27) C. Sætre , J. Stadsnes, H. Nesse, A. Aksnes, S. M. Petrinec, C. A. Barth,
D. N. Baker, R. R. Vondrak and N. Østgaard. Energetic electron precipitation
and the NO abundance in the upper atmosphere - A direct comparison during
geomagnetic storm.
J. Geophys. Res., Vol. 109, No. A9, A09302
10.1029/2004JA010485, 2004.
[pdf]
26) A. Åsnes, J. Stadsnes, J. Bjordal, N. Østgaard, M. Schulz, D. L. Detrick, T. J. Rosenberg,
S. E. Haaland, H. Singer. Pi2-pulsations observed in energetic electron precipitation and magnetic
field in association with a substorm surge.
Ann. Geophys., 22 (6): 2097-2105, 2004.
[pdf]
25) N. Østgaard, S. B. Mende , H. U. Frey , T. J. Immel, L. A. Frank, J. B.
Sigwarth, T. J. Stubbs. Interplanetary magnetic field control of the location of
substorm onset and auroral features in the conjugate hemispheres.
J. Geophys. Res., Vol. 109, No. A7, A07204, 10.1029/2003JA010370, 2004
[pdf]
24) C. J. Farrugia, P. E. Sandholt, R. B. Torbert, N. Østgaard. Temporal and spatial
aspects of the cusp inferred from local and global ground- and space-based
observations in a case study.
J. Geophys. Res., Vol. 109, No. A4, A04209
10.1029/2003JA010121, 2004.
[pdf]
23) H.U. Frey , N. Østgaard, T.J. Immel, H. Korth, S.B. Mende,
Seasonal dependence of localized, High Latitude Dayside Aurora (HiLDA).
J. Geophys. Res., Vol. 109, No. A4, A04303, doi: 10.1029/2003JA010293, 2004.
[pdf]
22) A. Aksnes, J Stadsnes, G. Lu, N. Østgaard, R. R. Vondrak, D. L. Detrick, T. J. Rosenberg,
G. A. Germany, M. Schulz. Effects of energetic electrons on the electrondynamics in the ionosphere.
Ann. Geophys., 2, 475 - 496, 2004.
[pdf]
21) N. Østgaard, S. B. Mende, H. U.
Frey, L. A. Frank , J. B. Sigwarth. Observations of non-conjugate theta
aurora.
Geophys. Res. Lett., Vol. 30, No. 21, 2125, doi: 10.1029/2003GL017914, 2003.
[pdf]
20) M. Meurant, J.-C. Gérard, B. Hubert, C. Blockx,
N. Østgaard, S.B. Mende.
Dynamics of global scale electron and proton precipitation induced by a solar wind pressure pulse.
Geophys. Res. Lett., Vol. 30, No. 20, 2032, doi: 10.1029/2003GL018017, 2003
[pdf]
19) S. B. Mende, C. W. Carlson, H. U. Frey, L. M. Peticolas, N. Østgaard.
FAST and IMAGE-FUV observations of a Substorm onset.
J. Geophys. Res.,Vol. 108, (A9), 1344, doi:10.1029/2002JA009787, 2003.
[pdf]
18) H. U. Frey, S. B. Mende, T. J. Immel, S. A. Fuselier, N. Østgaard. Proton aurora in the
CUSP during southward IMF.
J. Geophys. Res.,108 (A7), 1277 , doi:10.1029/2003JA009861R, 2003.
[pdf]
17) N. Østgaard, S. B. Mende, H. U. Frey, G. R. Gladstone, H. Lauche.
Neutral hydrogen density profiles derived from geocoronal imaging.
J. Geophys. Res., Vol. 108, No. A7, 1300, doi:10.1029/2002JA009749, 2003.
[pdf]
16) T. Christensen, N. Østgaard, T. J. Rosenberg, D. L. Detrick, G. A. Germany,
P. Stauning. Conjugate high-intensity energetic electron precipitation at high latitude.
Ann. Geophysicae, 21, 1443-1455, 2003 .
[pdf]
15) T. J. Immel, S. B. Mende, H. U. Frey, N. Østgaard, G. R. Gladstone. Effect of the July 14, 2000 solar flare
on Earth's FUV emissions.
J. Geophys. Res., Vol. 108 (A4), 1155, doi:10.1029/2001JA009060, 2003.
[pdf]
14) H. U. Frey, T. J. Immel, G. Lu, J. Bonnell, S. A. Fuselier, S. B. Mende, B. Hubert, N. Østgaard, G. Le.
Properties of localized, high latitude, dayside aurora.
J. Geophys. Res., Vol. 108 (A4), 8008, doi:10.1029/2002JA009356, 2003.
[pdf]
13) N. Østgaard, D. L. Detrick, T. J. Rosenberg, R. R. Vondrak, H. U. Frey, S. B. Mende, S. E. Håland, J.
Stadsnes, High-latitude dayside energetic precipitation and IMF BZ rotations.
J. Geophys. Res., Vol. 108 (A4), 8013, doi:10.1029/2002JA009350, 2003
[pdf]
12) N. Østgaard, G. A. Germany, J. Stadsnes, R. R. Vondrak. Energy analysis of substorms based on remote sensing
techniques, solar wind measurements and geomagnetic indices.
J. Geophys. Res.,
Vol. 107, NO. A9, 1233, doi: 10.1029/2001JA002002, 2002.
[pdf]
11) N. Østgaard, R. R. Vondrak, J. W. Gjerloev, G. A. Germany. A relation between the energy deposition by
electron precipitation and geomagnetic indices during substorms.
J. Geophys. Res.,
Vol. 107, NO. A9, 1246, doi: 10.1029/2001JA002003, 2002.
[pdf]
10) J. A. Slavin, D. H. Fairfield, R. P. Lepping, M. Hesse, A. Ieda, E. Tanskanen, N. Østgaard, T. Mukai, T.
Nagai, H. J. Singer, P. R. Sutcliffe. Simultaneous observations of earthward flow bursts and plasmoid
ejection during magnetospheric substorms.
J. Geophys. Res.,Vol. 107, NO. A7, 10.1029/2000JA003501, 2002.
[pdf]
9) A. Aksnes, J. Stadsnes, J. Bjordal, N. Østgaard, R. R. Vondrak, D. L. Detrick, T. J. Rosenberg, G. A.
Germany, D. Chenette. Instantaneous ionosphericglobal conductance maps during an isolated substorm.
Ann.
Geophysicae, 20, 1181 - 1191, 2002.
[pdf]
8) N. Østgaard, J. Stadsnes, J. Bjordal, G. A. Germany, R. R. Vondrak, G. K. Parks, S. A Cummer, D. L.
Chenette, J. G. Pronko. Auroral electron distributions derived from combined UV and X-ray emissions.
J. Geophys. Res., Vol.106, 26,081 - 26,090, 2001.
[pdf]
7) J. Bjordal, L. Borovkov, I. Kornilov, T. Kornilova, L. Lazutin, N. Østgaard, J. Stadsnes, G. Starkov, E.
Thorsen, S. Chernouss. Structure of polar aurora over Kola Peninsula and X-ray oval measured by Polar
satellite on February 9, 1997.
Geomagnetism and Aeronomie, No.3, 2000.
6) N. Østgaard, J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A Cummer, D. L. Chenette, M. Schulz, J. G.
Pronko. Cause of the localized maximum of X-ray emission in the morning sector: A comparison with electron
measurements.
J. Geophys. Res., Vol. 105, No A9, p. 20,869 - 20,885, 2000.
[pdf]
5) N. Østgaard, J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A Cummer, D. L. Chenette, M. Schulz, G. K. Parks, M.
J. Brittnacher, D. L. McKenzie, J. G. Pronko. Global X-ray emission during an isolated substorm - A case
study.
J. Atmos. Solar-Terr. Phys., Vol. 62 (10), p. 889 - 900, 2000.
[pdf]
4) S. A. Cummer, R. R. Vondrak, N. Østgaard, J. Bjordal, J. Stadsnes, D. L. Chenette, G. K. Parks, M. J.
Brittnacher, L. Frank and J. Sigwarth. Global multi-spectral auroral imaging of an isolated substorm.
Geophys. Res. Letter, Vol 27, No 5, p. 637-640, 2000.
[pdf]
3) S. Håland, N. Østgaard, J. Bjordal, J. Stadsnes, S. Ullaland, G. D. Reeves, D. L. Chenette, B. Wilken, T.
Yamamoto, T. Doke, G. K. Parks, M. J. Brittnacher. Magnetospheric and Ionospheric Response to a Substorm:
Geotail HEP-LD and Polar PIXIE Observations.
J. Geophys. Res., Vol. 104, No. A12, p. 28,459. 1999.
[pdf]
2) N. Østgaard, J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A Cummer, D. L. Chenette, G. K. Parks, M. J.
Brittnacher, D. L. McKenzie. Global Scale Electron Precipitation Features seen in UV and X-rays During
Substorms.
J. Geophys. Res., Vol. 104, p. 10,191 - 10,204, 1999.
[pdf]
1) N. Østgaard, J. Stadsnes, K. Aarsnes, F. Søraas, Karl Måseide, M. Smith, J.Sharber. Simultaneous
Measurements of X-rays and Electrons During a Pulsating Aurora.
Ann. Geophysicae, 16, 148 - 160, 1998.
[pdf]
2) N. Østgaard and E. Tanskanen. Energetics of isolated and stormtime substorms.
Disturbances in Geospace:
The Storm-Substorm Relationship, Geophysical Monograph 142. doi: 10.1029/142GM14, 2003.
[pdf]
1) D. L. Chenette, W. L. Imhof, S. M. Petrinec, M. Schulz, J. Mobilia, J. G. Pronko, M. A. Rinaldi, J. B.
Cladis, F. Fenrich, N. Østgaard, M. C. McNab. Global Energy-Resolved X-Ray Images of Northern Aurora and
Their Mappings to the Equatorial Magnetosphere.
in The Physics of Sun-Earth Plasma and Field Processes,
edited by J. L. Burch,
Geophysical Monograph Series, AGU, Washington, D.C., 109, 1998.
6) N. Østgaard , S. B. Mende, H. U. Frey, J. B. Sigwarth, A. Aasnes, J. Weygand.
Conjugate imaging of substorms
Proceedings from the ICS 8, 2006, in Banff, Canada, ISBN 978-0-88953-312-7, 2007.
[pdf]
5) T. Neubert, I. Kuvvetli, C. Budtz-Jorgensen, N. Østgaard, V. Reglero,
N. Arnold. The Atmosphere-Space Interactions Monitor (ASIM) for the International
Space Station. Proceedings from the ILWS Goa Workshop. p 448, ISBN-81-87099-40-2,
Quest Publications, 2006.
[pdf]
4) J. Nystrand, K. Brønstad, G. Eigen, F. Eisele, P. Fischer, H.
Helstrup, N. Herrmann, V. Lindenstruth, R. Männer, K. Meier, N. Østgaard, D.
Röhrich, B. Skaali, J. Stachel, J. Stadsnes, S. Stapnes, B. Stugu, B.G.
Svensson, T. Tveter, K. Ullaland, and U. Uwer. The International Research
Training Group. Development and Application of Intelligent Detectors.
Proceedings from the EUI-Net conference, Tallin, May, 2006.
[pdf]
3) O. Amm, A. Aksnes, J. Stadsnes, N. Østgaard, R. R. Vondrak, G. A. Germany,
I. Sillanpaa. Observations and analysis of ionospheric electrodynamics during
a substorm recovery phase using the MIRACLE network.
Proceedings from the ICS 7 in Finland, 2004.
[pdf]
2) A. Bhardwaj , G. R. Gladstone, R. F. Elsner, J. H. Waite, Jr., D. Grodent,
T. E. Cravens, R. R. Howell, A. E. Metzger, N. Østgaard, A. Maurellis,
R. E. Johnson, M. C. Weisskopf, T. Majeed , P. G. Ford, A. F. Tennant,
J. T. Clarke, W. S. Lewis, K. C. Hurley, F. J. Crary, E. D. Feigelson,
G. P. Garmire, D. T. Young, M. K. Dougherty, S. A. Espinosa, J.-M. Jahn.
Soft X-ray emissions from planets, moons and comets.
ESA-SP-514, Proc. ESLAB 36
Symposium, 'Earth-Like Planets and Moons', ESTEC, Noordwijk,
3-8 June 2002, pp215-226. 2002.
[pdf]
1) N. Østgaard, J. Stadsnes, J. Bjordal, E. Thorsen, R. R. Vondrak, S. A. Cummer, D. L. Chenette, G. K. Parks,
M. J. Brittnacher, D. L. McKenzie. Global Scale Electron Precipitation During Substorm Expansions.
Proceedings of the International Conference on Substorms -4, 55 - 58, 1998, Terra Scientific Publishing
Company, Tokyo, edited by S. Kokubun and Y. Kamide.
[pdf]
2) N. Østgaard, J. Bjordal, J. Stadsnes, E. Thorsen. PIXIE data processing at the University of Bergen.
Scientific/Technical Report No 1999-05, Dept. of Physics, University of Bergen, ISSN 0803-2696, May 1999.
[pdf]
1) N. Østgaard, J. Stadsnes, K. Aarsnes, F. Søraas, M. Smith. PULSAUR II Launched 01.23 MLT 9.2.1994: X-ray
Measurements During a Pulsating Aurora.
Scientific/Technical Report No 1996-08, Dept. of Physics, University
of Bergen, ISSN 0803-2696, August 1996