Ionospheric long-term trends for South American mid-latitudes

✍ Scribed by A.J Foppiano; L Cid; V Jara

• Book ID: 104407893
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 253 KB
• Volume: 61
• Category: Article
• ISSN: 1364-6826
• DOI: 10.1016/s1364-6826(99)00025-5

✦ Synopsis

Using ionosonde made observations at Concepcio n (36.88S; 73.08W) for the 1958±1994 interval, long-term trends of critical frequency (foF2) and peak height (hmF2) of the ionospheric F2-layer are analysed. The trends found for dierent times-of-day and all seasons are consistent with an increasing diurnal-variation amplitude of both foF2 and hmF2. An increasing hmF2 trend of up to 1.5 km/year found between midnight and dawn during winter has no precedent. It is suggested that these long-term amplitude changes may be associated with changes in the prevailing thermospheric meridional neutral winds.