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D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989.

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D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989. / Ranta, H.; Ranta, A.; Yousef, S. M. et al.
In: Journal of Atmospheric and Terrestrial Physics, Vol. 55, No. 4-5, 1993, p. 751-766.

Research output: Contribution to Journal/Magazine › Journal article

Harvard

Ranta, H, Ranta, A, Yousef, SM, Burns, J & Stauning, P 1993, 'D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989.', Journal of Atmospheric and Terrestrial Physics, vol. 55, no. 4-5, pp. 751-766. https://doi.org/10.1016/0021-9169(93)90018-T

APA

Ranta, H., Ranta, A., Yousef, S. M., Burns, J., & Stauning, P. (1993). D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989. Journal of Atmospheric and Terrestrial Physics, 55(4-5), 751-766. https://doi.org/10.1016/0021-9169(93)90018-T

Vancouver

Ranta H, Ranta A, Yousef SM, Burns J, Stauning P. D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989. Journal of Atmospheric and Terrestrial Physics. 1993;55(4-5):751-766. doi: 10.1016/0021-9169(93)90018-T

Author

Ranta, H. ; Ranta, A. ; Yousef, S. M. et al. / D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989. In: Journal of Atmospheric and Terrestrial Physics. 1993 ; Vol. 55, No. 4-5. pp. 751-766.

Bibtex

@article{2e9dc8429f314457bcf791b5d9ad2dbe,
title = "D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989.",
abstract = "During the years 1981–1989, 71 solar proton events altogether were observed. Dividing the events into strong, p.f.u. > 1000 (p.f.u.—proton flux measured at geosynchronous satellite orbit in units of (cm2 s sr)−1), medium, 100 < p.f.u. < 1000 and weak events, p.f.u. < 100, only the strong and medium events have a considerable effect on the lower ionosphere. The mean daily absorption at 30 MHz (A), measured in the auroral zone, is >2 dB during strong events, <2 dB during medium events and < l dB during weak events. The most active year during the EISCAT operation was 1989 when 23 solar proton events were observed including six strong events. Diurnal variation of the electron density in the D-region during PCA is a function of the solar zenith angle. However, south of L = 5 a minimum in absorption is observed during the noon hours. During sunrise the absorption increases simultaneously with solar elevation angle, but during sunset there is about 2 h delay between the decrease of absorption and the solar elevation angle.",
author = "H. Ranta and A. Ranta and Yousef, {S. M.} and J. Burns and P. Stauning",
year = "1993",
doi = "10.1016/0021-9169(93)90018-T",
language = "English",
volume = "55",
pages = "751--766",
journal = "Journal of Atmospheric and Terrestrial Physics",
publisher = "Pergamon Press Ltd.",
number = "4-5",

}

RIS

TY - JOUR

T1 - D-region observations of polar cap absorption events during the EISCAT operation in 1981–1989.

AU - Ranta, H.

AU - Ranta, A.

AU - Yousef, S. M.

AU - Burns, J.

AU - Stauning, P.

PY - 1993

Y1 - 1993

N2 - During the years 1981–1989, 71 solar proton events altogether were observed. Dividing the events into strong, p.f.u. > 1000 (p.f.u.—proton flux measured at geosynchronous satellite orbit in units of (cm2 s sr)−1), medium, 100 < p.f.u. < 1000 and weak events, p.f.u. < 100, only the strong and medium events have a considerable effect on the lower ionosphere. The mean daily absorption at 30 MHz (A), measured in the auroral zone, is >2 dB during strong events, <2 dB during medium events and < l dB during weak events. The most active year during the EISCAT operation was 1989 when 23 solar proton events were observed including six strong events. Diurnal variation of the electron density in the D-region during PCA is a function of the solar zenith angle. However, south of L = 5 a minimum in absorption is observed during the noon hours. During sunrise the absorption increases simultaneously with solar elevation angle, but during sunset there is about 2 h delay between the decrease of absorption and the solar elevation angle.

AB - During the years 1981–1989, 71 solar proton events altogether were observed. Dividing the events into strong, p.f.u. > 1000 (p.f.u.—proton flux measured at geosynchronous satellite orbit in units of (cm2 s sr)−1), medium, 100 < p.f.u. < 1000 and weak events, p.f.u. < 100, only the strong and medium events have a considerable effect on the lower ionosphere. The mean daily absorption at 30 MHz (A), measured in the auroral zone, is >2 dB during strong events, <2 dB during medium events and < l dB during weak events. The most active year during the EISCAT operation was 1989 when 23 solar proton events were observed including six strong events. Diurnal variation of the electron density in the D-region during PCA is a function of the solar zenith angle. However, south of L = 5 a minimum in absorption is observed during the noon hours. During sunrise the absorption increases simultaneously with solar elevation angle, but during sunset there is about 2 h delay between the decrease of absorption and the solar elevation angle.

U2 - 10.1016/0021-9169(93)90018-T

DO - 10.1016/0021-9169(93)90018-T

M3 - Journal article

VL - 55

SP - 751

EP - 766

JO - Journal of Atmospheric and Terrestrial Physics

JF - Journal of Atmospheric and Terrestrial Physics

IS - 4-5

ER -