Browsing Bergen Open Research Archive by Author "Johnsen, Magnar Gullikstad"
Now showing items 1-5 of 5
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Challenges and Strategic Research Plans for Earth and Heliosphere: Research Infrastructures, Projects and Initiatives
Mann, Ingrid; Kauristie, Kirsti; Bamford, Ruth; McCrea, Ian; Moen, Jøran Idar; Oksavik, Kjellmar; Yamauchi, Masanori; Johnsen, Magnar Gullikstad; Turunen, Esa (Peer reviewed; Journal article, 2018-07-24)We describe existing research infrastructures relevant for space weather and open issues of space weather research including the need for sustainable observation networks and for high-quality data products as basis for ... -
How Often Do Thermally Excited 630.0 nm Emissions Occur in the Polar Ionosphere?
Kwagala, Norah Kaggwa; Oksavik, Kjellmar; Lorentzen, Dag Arne; Johnsen, Magnar Gullikstad (Peer reviewed; Journal article, 2018-01)This paper studies thermally excited emissions in the polar ionosphere derived from European Incoherent Scatter Svalbard radar measurements from the years 2000–2015. The peak occurrence is found around magnetic noon, where ... -
On the contribution of thermal excitation to the total 630.0 nm emissions in the northern cusp ionosphere
Kwagala, Norah Kaggwa; Oksavik, Kjellmar; Lorentzen, Dag Arne; Johnsen, Magnar Gullikstad (Peer reviewed; Journal article, 2017-01)Direct impact excitation by precipitating electrons is believed to be the main source of 630.0 nm emissions in the cusp ionosphere. However, this paper investigates a different source, 630.0 emissions caused by thermally ... -
Seasonal and Solar Cycle Variations of Thermally Excited 630.0 nm Emissions in the Polar Ionosphere
Kwagala, Norah Kaggwa; Oksavik, Kjellmar; Lorentzen, Dag Arne; Johnsen, Magnar Gullikstad; Laundal, Karl Magnus (Peer reviewed; Journal article, 2018-08)Solar cycle and seasonal variations have been found in the occurrence of strong thermally excited 630.0 nm emissions in the polar ionosphere. Measurements from the European Incoherent Scatter Svalbard Radar have been used ... -
Solar illumination dependence of the auroral electrojet intensity: Interplay between the solar zenith angle and dipole tilt
Ohtani, Shinici; Gjerløv, Jesper; Johnsen, Magnar Gullikstad; Yamauchi, Masatoshi; Brändström, Urban; Lewis, Andrew M. (Peer reviewed; Journal article, 2019-08)The present study investigates the dependence of the local auroral electrojet (AEJ) intensity on solar illumination by statistically examining northward geomagnetic disturbances in the auroral zone in terms of the solar ...