Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item:

Authors: Belehaki, A.*
Moraitis, G.*
Tsagouri, I.*
Title: On the derivation of an hourly local index to define the normal ionosphere
Issue Date: Jan-2000
Series/Report no.: 43/1
Keywords: reference ionosphere
ionospheric disturbance
ionospheric indices
Abstract: In this paper an hourly local ionospheric index f n F 2 is proposed to define the normal level of the undisturbed ionosphere. For the determination of this index a model is developed where the normal values of the f 0 F 2 parameter were reproduced using multiple regression analysis. For each month of the year, for a given station, a set of 48 or 72 coefficients are calculated, depending on the monthly sunspot activity. Then, the normal values of the f 0 F 2 parameter are computed as a function of the daily sunspot number. The analysis of the model results revealed the following characteristics for the f n F 2 index: first, the temporal variations that characterize the normal ionosphere, imposing some artificial effects on the monthly median values, are eliminated from the newly derived f n F 2 index. Second, the f n F 2 index does not follow the false steplike variations observed in the monthly median f 0 F 2 time series, in transition periods from one month to another. Third, during intervals of low magnetospheric activity,the f n F 2 index presents a very good degree of fit with the observed f 0 F 2 parameter, compared to the monthly median f 0 F 2 behaviour. During disturbed conditions, the f n F 2 index remains at the normal level, whereas median values are affected by ionospheric disturbances. In general, the data analysis showed that the f n F 2 index varies only with the daily sunspot number Rz and is independent of the magnetospheric activity, approaching the level of the normal ionosphere with a high degree of confidence.
Appears in Collections:01.02.06. Instruments and techniques
Annals of Geophysics

Files in This Item:

File SizeFormatVisibility
13.pdf6.4 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Share this record




Stumble it!



Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA