Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum

V. V. Paznukhov, C. S. Carrano, P. H. Doherty, K. M. Groves, R. G. Caton, C. E. Valladares, G. K. Seemala, C. T. Bridgwood, J. Adeniyi, L. L N Amaeshi, B. Damtie, F. D'Ujanga Mutonyi, J. O H Ndeda, P. Baki, O. K. Obrou, B. Okere, G. M. Tsidu

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

We report on the longitudinal, local time and seasonal occurrence of equatorial plasma bubbles (EPBs) and L band (GPS) scintillations over equatorial Africa. The measurements were made in 2010, as a first step toward establishing the climatology of ionospheric irregularities over Africa. The scintillation intensity is obtained by measuring the standard deviation of normalized GPS signal power. The EPBs are detected using an automated technique, where spectral analysis is used to extract and identify EPB events from the GPS TEC measurements. Overall, the observed seasonal climatology of the EPBs as well as GPS scintillations in equatorial Africa is adequately explained by geometric arguments, i.e., by the alignment of the solar terminator and local geomagnetic field, or STBA hypothesis (Tsunoda, 1985, 2010a). While plasma bubbles and scintillations are primarily observed during equinoctial periods, there are longitudinal differences in their seasonal occurrence statistics. The Atlantic sector has the most intense, longest lasting, and highest scintillation occurrence rate in-season. There is also a pronounced increase in the EPB occurrence rate during the June solstice moving west to east. In Africa, the seasonal occurrence shifts towards boreal summer solstice, with fewer occurrences and shorter durations in equinox seasons. Our results also suggest that the occurrence of plasma bubbles and GPS scintillations over Africa are well correlated, with scintillation intensity depending on depletion depth. A question remains about the possible physical mechanisms responsible for the difference in the occurrence phenomenology of EPBs and GPS scintillations between different regions in equatorial Africa.

Original languageEnglish
Pages (from-to)675-682
Number of pages8
JournalAnnales Geophysicae
Volume30
Issue number4
DOIs
Publication statusPublished - 2012

Fingerprint

plasma bubbles
ultrahigh frequencies
scintillation
bubble
occurrences
plasma
GPS
solstices
climatology
Africa
geomagnetism
irregularities
geomagnetic field
phenomenology
spectral analysis
ionospherics
summer
spectrum analysis
standard deviation
depletion

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences (miscellaneous)
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Space and Planetary Science
  • Geology

Cite this

Paznukhov, V. V., Carrano, C. S., Doherty, P. H., Groves, K. M., Caton, R. G., Valladares, C. E., ... Tsidu, G. M. (2012). Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum. Annales Geophysicae, 30(4), 675-682. https://doi.org/10.5194/angeo-30-675-2012
Paznukhov, V. V. ; Carrano, C. S. ; Doherty, P. H. ; Groves, K. M. ; Caton, R. G. ; Valladares, C. E. ; Seemala, G. K. ; Bridgwood, C. T. ; Adeniyi, J. ; Amaeshi, L. L N ; Damtie, B. ; D'Ujanga Mutonyi, F. ; Ndeda, J. O H ; Baki, P. ; Obrou, O. K. ; Okere, B. ; Tsidu, G. M. / Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum. In: Annales Geophysicae. 2012 ; Vol. 30, No. 4. pp. 675-682.
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Paznukhov, VV, Carrano, CS, Doherty, PH, Groves, KM, Caton, RG, Valladares, CE, Seemala, GK, Bridgwood, CT, Adeniyi, J, Amaeshi, LLN, Damtie, B, D'Ujanga Mutonyi, F, Ndeda, JOH, Baki, P, Obrou, OK, Okere, B & Tsidu, GM 2012, 'Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum', Annales Geophysicae, vol. 30, no. 4, pp. 675-682. https://doi.org/10.5194/angeo-30-675-2012

Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum. / Paznukhov, V. V.; Carrano, C. S.; Doherty, P. H.; Groves, K. M.; Caton, R. G.; Valladares, C. E.; Seemala, G. K.; Bridgwood, C. T.; Adeniyi, J.; Amaeshi, L. L N; Damtie, B.; D'Ujanga Mutonyi, F.; Ndeda, J. O H; Baki, P.; Obrou, O. K.; Okere, B.; Tsidu, G. M.

In: Annales Geophysicae, Vol. 30, No. 4, 2012, p. 675-682.

Research output: Contribution to journalArticle

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T1 - Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum

AU - Paznukhov, V. V.

AU - Carrano, C. S.

AU - Doherty, P. H.

AU - Groves, K. M.

AU - Caton, R. G.

AU - Valladares, C. E.

AU - Seemala, G. K.

AU - Bridgwood, C. T.

AU - Adeniyi, J.

AU - Amaeshi, L. L N

AU - Damtie, B.

AU - D'Ujanga Mutonyi, F.

AU - Ndeda, J. O H

AU - Baki, P.

AU - Obrou, O. K.

AU - Okere, B.

AU - Tsidu, G. M.

PY - 2012

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N2 - We report on the longitudinal, local time and seasonal occurrence of equatorial plasma bubbles (EPBs) and L band (GPS) scintillations over equatorial Africa. The measurements were made in 2010, as a first step toward establishing the climatology of ionospheric irregularities over Africa. The scintillation intensity is obtained by measuring the standard deviation of normalized GPS signal power. The EPBs are detected using an automated technique, where spectral analysis is used to extract and identify EPB events from the GPS TEC measurements. Overall, the observed seasonal climatology of the EPBs as well as GPS scintillations in equatorial Africa is adequately explained by geometric arguments, i.e., by the alignment of the solar terminator and local geomagnetic field, or STBA hypothesis (Tsunoda, 1985, 2010a). While plasma bubbles and scintillations are primarily observed during equinoctial periods, there are longitudinal differences in their seasonal occurrence statistics. The Atlantic sector has the most intense, longest lasting, and highest scintillation occurrence rate in-season. There is also a pronounced increase in the EPB occurrence rate during the June solstice moving west to east. In Africa, the seasonal occurrence shifts towards boreal summer solstice, with fewer occurrences and shorter durations in equinox seasons. Our results also suggest that the occurrence of plasma bubbles and GPS scintillations over Africa are well correlated, with scintillation intensity depending on depletion depth. A question remains about the possible physical mechanisms responsible for the difference in the occurrence phenomenology of EPBs and GPS scintillations between different regions in equatorial Africa.

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Paznukhov VV, Carrano CS, Doherty PH, Groves KM, Caton RG, Valladares CE et al. Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum. Annales Geophysicae. 2012;30(4):675-682. https://doi.org/10.5194/angeo-30-675-2012