کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1777626 | 1021751 | 2009 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Observations on the variability and screening effect of Sporadic-E Observations on the variability and screening effect of Sporadic-E](/preview/png/1777626.png)
Sporadic-E is a problem in high latitude HF communications because of its irregular and as yet unpredictable behaviour. This paper characterises the change in E-layer critical frequency (foE) that occurs in the four hours following a storm sudden commencement (SSC) event which is a precursor to magnetospheric storms which adversely affect ionospheric communications.Following checks for any seasonal or solar activity dependency in the data, further analysis determines the occurrence of full blanketing (screening) Sporadic-E layer formation at high latitudes as seen on vertical ionosondes in Northern Finland (67° Latitude). An appropriate threshold value of foE is proposed that could be used following the commencement of ionospheric storms, indicating that there is a high probability that F-layer screening will occur. As far as the authors are aware this is the first statistical analysis of the onset of Sporadic-E following SSC.
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 71, Issue 12, August 2009, Pages 1353–1364