A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels
We report measured levels of very low frequency (VLF) radio noise at ∼10 kHz, due to lightning sferics, observed at Halley Station, Antarctica (76°S, 27°W) between 1971 and 1996. The observed VLF noise levels at Halley are a product of the thunderstorm source function and the transfer function for p...
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Language: | English |
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American Geophysical Union
1998
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Online Access: | http://nora.nerc.ac.uk/id/eprint/505030/ https://nora.nerc.ac.uk/id/eprint/505030/1/grl11790.pdf https://doi.org/10.1029/1998GL900146 |
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ftnerc:oai:nora.nerc.ac.uk:505030 2023-05-15T13:48:08+02:00 A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels Watkins, Nicholas W. Clilverd, Mark A. Smith, Andy J. Yearby, Keith H. 1998 text http://nora.nerc.ac.uk/id/eprint/505030/ https://nora.nerc.ac.uk/id/eprint/505030/1/grl11790.pdf https://doi.org/10.1029/1998GL900146 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/505030/1/grl11790.pdf Watkins, Nicholas W.; Clilverd, Mark A. orcid:0000-0002-7388-1529 Smith, Andy J.; Yearby, Keith H. 1998 A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels. Geophysical Research Letters, 25 (23). 4353-4356. https://doi.org/10.1029/1998GL900146 <https://doi.org/10.1029/1998GL900146> Publication - Article PeerReviewed 1998 ftnerc https://doi.org/10.1029/1998GL900146 2023-02-04T19:38:42Z We report measured levels of very low frequency (VLF) radio noise at ∼10 kHz, due to lightning sferics, observed at Halley Station, Antarctica (76°S, 27°W) between 1971 and 1996. The observed VLF noise levels at Halley are a product of the thunderstorm source function and the transfer function for propagation to the receiver in the waveguide formed by the Earth's surface and the ionosphere. Least squares fitting enables us to confirm the characteristic diurnal, annual and semi-annual periodicities found by the present authors in a separate paper. That method and also cross correlation of annual averaged 10 kHz VLF power with sunspot number shows a ∼4 dB peak-to-peak fluctuation at the ∼11-year solar cycle period, believed to be due to the influence of EUV flux on the the ionospheric D region. Finally we constrain any linear trend to 1.4±2.6 dB in 25 years. If a positive trend is present and is interpreted as a change in tropical South American lightning flash rate, it is less than 10%. Article in Journal/Newspaper Antarc* Antarctica Natural Environment Research Council: NERC Open Research Archive Halley Station ENVELOPE(-26.541,-26.541,-75.581,-75.581) Geophysical Research Letters 25 23 4353 4356 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
We report measured levels of very low frequency (VLF) radio noise at ∼10 kHz, due to lightning sferics, observed at Halley Station, Antarctica (76°S, 27°W) between 1971 and 1996. The observed VLF noise levels at Halley are a product of the thunderstorm source function and the transfer function for propagation to the receiver in the waveguide formed by the Earth's surface and the ionosphere. Least squares fitting enables us to confirm the characteristic diurnal, annual and semi-annual periodicities found by the present authors in a separate paper. That method and also cross correlation of annual averaged 10 kHz VLF power with sunspot number shows a ∼4 dB peak-to-peak fluctuation at the ∼11-year solar cycle period, believed to be due to the influence of EUV flux on the the ionospheric D region. Finally we constrain any linear trend to 1.4±2.6 dB in 25 years. If a positive trend is present and is interpreted as a change in tropical South American lightning flash rate, it is less than 10%. |
format |
Article in Journal/Newspaper |
author |
Watkins, Nicholas W. Clilverd, Mark A. Smith, Andy J. Yearby, Keith H. |
spellingShingle |
Watkins, Nicholas W. Clilverd, Mark A. Smith, Andy J. Yearby, Keith H. A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
author_facet |
Watkins, Nicholas W. Clilverd, Mark A. Smith, Andy J. Yearby, Keith H. |
author_sort |
Watkins, Nicholas W. |
title |
A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
title_short |
A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
title_full |
A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
title_fullStr |
A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
title_full_unstemmed |
A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels |
title_sort |
25-year record of 10 khz sferics noise in antarctica: implications for tropical lightning levels |
publisher |
American Geophysical Union |
publishDate |
1998 |
url |
http://nora.nerc.ac.uk/id/eprint/505030/ https://nora.nerc.ac.uk/id/eprint/505030/1/grl11790.pdf https://doi.org/10.1029/1998GL900146 |
long_lat |
ENVELOPE(-26.541,-26.541,-75.581,-75.581) |
geographic |
Halley Station |
geographic_facet |
Halley Station |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/505030/1/grl11790.pdf Watkins, Nicholas W.; Clilverd, Mark A. orcid:0000-0002-7388-1529 Smith, Andy J.; Yearby, Keith H. 1998 A 25-year record of 10 kHz sferics noise in Antarctica: Implications for tropical lightning levels. Geophysical Research Letters, 25 (23). 4353-4356. https://doi.org/10.1029/1998GL900146 <https://doi.org/10.1029/1998GL900146> |
op_doi |
https://doi.org/10.1029/1998GL900146 |
container_title |
Geophysical Research Letters |
container_volume |
25 |
container_issue |
23 |
container_start_page |
4353 |
op_container_end_page |
4356 |
_version_ |
1766248745335259136 |