On the source of the polar wind in the polar topside ionosphere: First results from the EISCAT Svalbard radar
2009 (English)In: Geophysical Research Letters, ISSN 0094-8276, Vol. 36, no 24, L24103- p.Article in journal (Refereed) Published
We present quantitative radar observations of both hydrogen ion (H+) and oxygen ion (O+) upflow in the topside polar ionosphere using measurements that were recently carried out with the EISCAT Svalbard Radar and the Reimei satellite. H+ upflow was clearly observed equatorward of the cusp above 500 km altitude. Within the cusp the H+ density was very low, and the upflow was dominated by O+ ions, but on closed field lines the H+ became the larger contributor to the upward flux above about 550 km. The total flux seemed to be conserved, and so below 550 km altitude O+ (with a small upward velocity of similar to 50 m s(-1)) appeared to determine the upward flux which was then maintained by H+! in the topside ionosphere. We also found that the H+ density in the topside polar ionosphere was several times higher than current predictions of ionospheric models like IRI2001.
Place, publisher, year, edition, pages
2009. Vol. 36, no 24, L24103- p.
IdentifiersURN: urn:nbn:se:uu:diva-148207DOI: 10.1029/2009GL041501ISI: 000273254700004OAI: oai:DiVA.org:uu-148207DiVA: diva2:401652