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A Study On The Change In Formation Of D-Layer Of The Atmosphere Of Grindavik, Iceland For 2015 Using A Signal Of 37.5 Khz
[Full Text]
AUTHOR(S)
Karan Bhatta, Balaram Khadka, Peter Wilhelm Schnoor
KEYWORDS
VLF/LF, D-layer, volcanic activity, sunrise terminator time, Sunset terminator time, VLF day,
ABSTRACT
The D-layer is the lowest layer of the ionosphere which is capable of reflecting Very Low Frequency (VLF)/Low Frequency (LF) waves. In this work, we analyze the VLF/LF waves of 37453.125 Hz transmitted from two VLF/LF transmitting towers in Grindavik, Iceland which was received in the Kiel Longwave Monitor, Germany for the year 2015. We did a graphical analysis of the variation of the intensity of the field associated with the VLF/LF of the respective frequency along with time. We recorded the Sunrise terminal time, the Sunset terminal time and compared the VLF/LF day and normal day, which is an indicator of the state of the formation of the D-layer. The comparison of sunrise and D-layer formation times with the standard 2σ lines was done. For several months such as January, February and March of 2015, intense anomalies were observed in both the sunrise terminator times and d-layer formation times. This gives us a possibility that the changes in these timings might be associated with intense volcanic activity which was observed in Iceland which stated off in Bardarbunga in August 2014 and ended only on 27th February 2015. Along with the volcanic activity, large amount of earthquakes were associated with the volcano. The magma released from the volcanoes along with huge amount of Radon gas released from the earthquakes might have caused these anomalies.
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