Different long-term trends of the oxygen red 630.0nm line nightglow intensity as the result of lowering the ionosphere F2 layer

706 8 2704 1 7793 document 2704 08 Didebulidze angeo 26-2069.pdf application/pdf 0d6e2bce566e0af87428279949e73768 MD5 407106 2014-01-27 12:27:07 http://eprints.iliauni.edu.ge/706/1/08%20Didebulidze%20angeo%2026-2069.pdf 706 1 1 application/pdf text ge public

08 Didebulidze angeo 26-2069.pdf

2720 2 7838 document 2720 lightbox.jpg image/png 5e10b61527c75aefca8111d2c22478b1 MD5 59341 2014-01-27 12:47:35 http://eprints.iliauni.edu.ge/706/2/lightbox.jpg 706 2 2 image/png other Thumbnails conversion from text to thumbnail_lightbox ge public

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http://eprints.org/relation/isVersionOf http://eprints.iliauni.edu.ge/id/document/2704 http://eprints.org/relation/isVolatileVersionOf http://eprints.iliauni.edu.ge/id/document/2704 http://eprints.org/relation/issmallThumbnailVersionOf http://eprints.iliauni.edu.ge/id/document/2704 archive 24 disk0/00/00/07/06 2014-01-29 19:47:06 2014-01-29 19:47:06 2014-01-29 19:47:06 article show Gudadze N. B. guda@iliauni.edu.ge Didebulidze G.G. didebulidze@iliauni.edu.ge Lomidze L. N. Javakhishvili G. Sh. Marsagishvili M. A. Todua M. Different long-term trends of the oxygen red 630.0nm line nightglow intensity as the result of lowering the ionosphere F2 layer pub QC fac_eng public Long-term observations of total nightglow intensity of the atomic oxygen red 630.0 nm line at Abastumani (41.75� N, 42.82� E) in 1957–1993 and measurements of the ionosphere F2 layer parameters from the Tbilisi ionosphere station (41.65� N, 44.75� E) in 1963–1986 have been analyzed. It is shown that a decrease in the long-term trend of the mean annual red 630.0 nm line intensity from the premidnight value (+0.770±1.045 R/year) to its minimum negative value (−1.080±0.670 R/year) at the midnight/after midnight is a possible result of the observed lowering of the peak height of the ionosphere F2 layer electron density hmF2 (−0.455±0.343 km/year). A theoretical simulation is carried out using a simple Chapman-type layer (damping in time) for the height distribution of the F2 layer electron density. The estimated values of the lowering in the hmF2, the increase in the red line intensity at pre-midnight and its decrease at midnight/after midnight are close to their observational ones, when a negative trend in the total neutral density of the upper atmosphere and an increase in the mean northward wind (or its possible consequence – a decrease in the southward one) are assumed. 2008-08 published Annales Geophysicae 26 European Geosciences Union 2069-2080 TRUE 0992-7689 http://www.ann-geophys.net http://www.ann-geophys.net/26/2069/2008/ the INTAS grant 03-51-6425 and GNSF/ST07/5-208