Egil Leer

• Garcia, Odd Erik; Leer, Egil; Pecseli, Hans & Trulsen, Jan Karsten (2015). Magnetic field-aligned plasma currents in gravitational fields. Annales Geophysicae. ISSN 0992-7689. 33(3), p. 257–266. doi: 10.5194/angeo-33-257-2015. Full text in Research Archive Show summary

  Analytical models are presented for currents along vertical magnetic field lines due to slow bulk electron motion in plasmas subject to a gravitational force. It is demonstrated that a general feature of this problem is a singularity in the plasma pressure force that develops at some finite altitude when a plasma that is initially in static equilibrium is set into slow motion. Classical fluid models thus do not allow general steady-state solutions for field-aligned currents. General solutions have to be non-stationary, varying on time scales of many periods of a plasma equivalent to the Brunt–Väisälä frequency. Except for very special choices of parameters, a steady-state solution exists only in an average sense. The conditions at large altitudes turn out to be extremely sensitive to even small changes in parameters at low altitudes. Low frequency fluctuations detected at large altitudes in the polar regions need not be caused by local low frequency instabilities, but merely reflect small fluctuations in conditions at low altitudes.

• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2007). Solar wind originating in funnels: fast or slow? Astronomy and Astrophysics (A & A). ISSN 0004-6361. 474, p. 997–1013. doi: 10.1051/20066311. Full text in Research Archive
• Lie-Svendsen, Øystein & Leer, Egil (2006). The Impact of Solar Eruptions on the Upper Chromosphere, Transition Region, and Corona. The Astrophysical Journal (ApJ). ISSN 0004-637X. 643, p. 1286–1303. doi: 10.1086/501432. Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2006). Improved gyrotropic transport equations for fully ionized magnetized gases: modelling the solar wind. Physica Scripta. ISSN 0031-8949. T122, p. 66–78. doi: 10.1088/0031-8949/2006/T122/01. Full text in Research Archive
• Killie, Mari Anne; Lie-Svendsen, Øystein & Leer, Egil (2005). The Helium Abundance of Quiescent Coronal Loops. The Astrophysical Journal (ApJ). ISSN 0004-637X. 632, p. L155–L158. Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2005). Modeling helium in the solar wind with new gyrotropic transport equations. ESA SP. ISSN 0379-6566. p. 487–490. Full text in Research Archive
• Killie, Mari Anne; Lie-Svendsen, Øystein & Leer, Egil (2005). Modeling Helium in Closed Coronal Structures. ESA SP. ISSN 0379-6566. p. 147–152. Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2005). Describing the flow of fully ionized, magnetized gases: improved gyrotropic transport equations. Journal of Plasma Physics. ISSN 0022-3778. 71(5), p. 611–629. doi: 10.1017/S0022377804003393. Full text in Research Archive
• Endeve, Eirik; Lie-Svendsen, Øystein; Hansteen, Viggo & Leer, Egil (2005). Release of Helium from Closed-Field Regions of the Sun. The Astrophysical Journal (ApJ). ISSN 0004-637X. 624, p. 402–413. Full text in Research Archive
• Killie, Mari Anne; Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2004). Improved transport equations for fully ionized gases. The Astrophysical Journal (ApJ). ISSN 0004-637X. 604, p. 842–849. Full text in Research Archive
• Endeve, Eirik; Holzer, T.E. & Leer, Egil (2004). Helmet streamers gone unstable: Two-Fluid Magnetohydrodynamic Models of the Solar Corona. The Astrophysical Journal (ApJ). ISSN 0004-637X. 603, p. 307–307. Full text in Research Archive
• Endeve, Eirik; Leer, Egil & Holzer, T.E. (2003). Two-dimensional Magnetohydrodynamic Models of the Solar Corona: Mass Loss from the Streamer Belt. The Astrophysical Journal (ApJ). ISSN 0004-637X. 589, p. 1040–1053. Full text in Research Archive
• Lie-Svendsen, Øystein; Hansteen, Viggo & Leer, Egil (2003). Helium Abundance in the Corona and Solar Wind: Gyrotropic Modeling from the Chromosphere to 1 AU. The Astrophysical Journal (ApJ). ISSN 0004-637X. 596(1), p. 621–645. Full text in Research Archive
• Lie-Svendsen, Øystein; Hansteen, Viggo; Leer, Egil & Holzer, T.E. (2002). The effect of transition region heating on the solar wind from coronal holes. The Astrophysical Journal (ApJ). ISSN 0004-637X. 566, p. 562–576. Full text in Research Archive
• Endeve, Eirik & Leer, Egil (2001). Coronal heating and solar wind acceleration : gyrotropic electron-proton solar wind. Solar Physics. ISSN 0038-0938. 200, p. 235–250. Full text in Research Archive
• Lie-Svendsen, Øystein; Leer, Egil & Hansteen, Viggo (2001). A 16-moment solar wind model: from the chromosphere to 1 AU. Journal of Geophysical Research (JGR). ISSN 0148-0227. 106(A5), p. 8217–8232. Full text in Research Archive
• Lie-Svendsen, Øystein & Leer, Egil (2000). The electron velocity distribution in the high-speed solar wind: modeling the effects of protons. Journal of Geophysical Research (JGR). ISSN 0148-0227. 105(A1), p. 35–46. Full text in Research Archive
• Leer, Egil & Marsch, E. (1999). Working Group I report: solar wind models from the sun to 1 AU: contraints by "in situ" and remote sensing measurements. Space Science Reviews. ISSN 0038-6308. 87, p. 67–77. Full text in Research Archive
• Lie-Svendsen, Øystein & Leer, Egil (1999). Electron heat conduction in the solar transition region: validity of the classical description. The Astrophysical Journal (ApJ). ISSN 0004-637X. p. 1056–1065. Full text in Research Archive
• Olsen, E.L. & Leer, Egil (1999). A study of solar wind acceleration based on gyro-tropic transport equations. Journal of Geophysical Research (JGR). ISSN 0148-0227. 104(A5), p. 9963–9973. Full text in Research Archive

View all works in NVA

• Leer, Egil (2009). Populærforedrag. Full text in Research Archive
• Leer, Egil (2009). Intervju om IBEX-prosjektet. [Radio]. NRK P2 "Verdt å vite". Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2005). Modeling the solar wind with new transport equations. Full text in Research Archive
• Killie, Mari Anne; Lie-Svendsen, Øystein & Leer, Egil (2005). Modeling Helium in Closed Coronal Structures. Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2004). Gyrotropic transport equations for a magnetized, fully ionized gas. Full text in Research Archive
• Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2004). Transport equations for a magnetized, fully ionized gas. Full text in Research Archive
• Bogdan, T.J.; Carlsson, Mats; Hansteen, Viggo; Heggland, Lars; Leer, Egil & Mcmurry, Andrew David [Show all 7 contributors for this article] (2004). Mode Conversion in Magneto-Atmospheres. Full text in Research Archive
• Killie, Mari Anne; Janse, Åse Marit; Lie-Svendsen, Øystein & Leer, Egil (2004). Improved Transport Equations For Fully Ionized Gases. Full text in Research Archive
• Lie-Svendsen, Øystein; Hansteen, Viggo & Leer, Egil (2001). Coupling between chromosphere and corona: why it matters for the solar wind. Full text in Research Archive
• Leer, Egil (2001). Solar wind: theory. In Murdin, Paul (Eds.), Encyclopedia of astronomy and astrophysics. IOP Publishing, Bristol ; Nature Publishing Group, London. ISSN 9780333750889. p. 2882–2886. Full text in Research Archive
• Leer, Egil (2000). Solstormer og romvær. Astronomi. ISSN 0802-7587. 30(4), p. 16–18. Full text in Research Archive
• Lemstad, Frank & Leer, Egil (2000). Romvær til besvær. Astronomi. ISSN 0802-7587. 30(4), p. 20–23. Full text in Research Archive
• Hansteen, Viggo; Leer, Egil & Lie-Svendsen, Øystein (1999). Advances in modelling the fast solar wind. Full text in Research Archive
• Hansteen, Viggo; Leer, Egil & Holzer, T.E. (1999). The origin of the high speed solar wind. Full text in Research Archive

View all works in NVA