uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Artificial field-aligned irregularities in the nightside auroral ionosphere
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
Show others and affiliations
2006 (English)In: Advances in Space Research, ISSN 0273-1177, Vol. 38, no 11, 2503-2510 p.Article in journal (Refereed) Published
Abstract [en]

Experimental results from two Tromso HF heating experiments in the nightside high latitudinal F region are examined. Bi-static scatter measurements of HF diagnostic signals were carried out on the London-Tromso-St. Petersburg and Pori-Tromso-St. Petersburg paths using a Doppler spectral method. The properties and behaviour of artificial field-aligned small-scale irregularities (striations) in the nightside high latitudinal F-region in course of the Tromso ionospheric modification experiments are studied. Experimental studies have been performed by the use of phased array I with a beamwidth of 6 degrees instead of 12-14 degrees in phased array 2, more often used in Tromso ionospheric modification experiments. The comparison between two experiments carried out in the same background geophysical conditions, shows the strongest striations in the field-aligned position of the heater beam. Possible explanation for this angular dependence is self-focusing of HF pump waves on striations causing the energy to be distributed asymmetrically. A principal question related to HF heating experiments is how is the disturbed auroral ionosphere modified. The results obtained on two paths simultaneously have shown that the strong heater-induced striations were observed along with natural ones. Velocities of heater-induced striations were quite different at different parts of the heated volume. It is suggested that the heater-induced striations can be grouped in two patches at different heights possibly due to the temperature-gradient-driven instability.

Place, publisher, year, edition, pages
2006. Vol. 38, no 11, 2503-2510 p.
Keyword [en]
powerful HF radio wave, auroral ionosphere, nonlinear phenomena, artificial field-aligned irregularities, ionosphere modification, bistatic HF doppler radio scatter
National Category
Physical Sciences
URN: urn:nbn:se:uu:diva-153028DOI: 10.1016/j.asr.2004.12.008ISI: 000202988800032OAI: oai:DiVA.org:uu-153028DiVA: diva2:415021
Available from: 2011-05-05 Created: 2011-05-05 Last updated: 2011-05-05Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Swedish Institute of Space Physics, Uppsala Division
In the same journal
Advances in Space Research
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 187 hits
ReferencesLink to record
Permanent link

Direct link