Please use this identifier to cite or link to this item: http://nopr.niscair.res.in/handle/123456789/14029
Title: Solar EUV flux (0.1-50 nm), F10.7 cm flux, sunspot number and the total electron content in the crest region of equatorial ionization anomaly during the deep minimum between solar cycle 23 and 24
Authors: Chakrabarty, D
Bagiya, Mala S
Thampi, Smitha V
Iyer, K N
Keywords: Total electron content (TEC)
Solar EUV flux, Solar F10.7 cm flux
Sunspot number
ionization anomaly (EIA)
Deep solar minimum
Issue Date: Apr-2012
Publisher: NISCAIR-CSIR, India
Abstract: The daily peak total electron content (TEC), recorded from Rajkot (22.29°N, 70.74°E, 31.6°N dip angle), is analyzed to investigate the combined roles of the solar cycle effect and neutral dynamical processes on the TEC variation over the equatorial ionization anomaly (EIA) crest region during the deep minimum between solar cycle 23 and 24. It is found that the mean peak TEC level decreases monotonically during 2005-2008 in accordance with the mean solar EUV (0.1-50 nm) and F10.7 cm (2800 MHz) flux (1 sfu = 10<sup>-22</sup> Wm<sup>-2</sup> Hz<sup>-1</sup>). The mean peak TEC level over Rajkot seems to respond to the mean EUV flux (or F10.7 cm flux) level by simultaneously registering an increasing trend from February 2009 onwards. Most importantly, the rate of increase in the mean peak TEC level during 2009 over Rajkot is greater than the corresponding rates of increase in the mean EUV and F10.7 cm flux levels indicating the important additional roles played possibly by the residual (difference between annual averages) effects of the trans-equatorial winds, compositional changes, etc. over this time scale. It is verified that the inherent solar periodicity of around six months has no consistent causal connection with the semi-annual variation in TEC. A few spectral differences are also observed between the EUV flux and F10.7 cm flux. The annually averaged peak TEC value over Rajkot is found to be well correlated (R = 0.98) with the corresponding annually averaged F10.7 cm flux during 2005-2009. Statistical analyses also indicate that the time of occurrence of maximum TEC over Rajkot changes randomly during 2005-2009 indicating the possible role played by the processes related to the residual trans-equatorial wind over the years.
Description: 110-120
URI: http://hdl.handle.net/123456789/14029
ISSN: 0975-105X (Online); 0367-8393 (Print)
Appears in Collections:IJRSP Vol.41(2) [April 2012]

Files in This Item:
File Description SizeFormat 
IJRSP 41(2) 110-120.pdf576.68 kBAdobe PDFView/Open


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