|
Detailed Reference Information |
Kim, Y.H., Hong, S.S. and Weinberg, J.L. (2002). Equatorial spread F found in 5577 Å and 6300 Å airglow observations from Hawaii. Journal of Geophysical Research 107: doi: 10.1029/2001JA009232. issn: 0148-0227. |
|
We have searched for F region ionospheric disturbances in a database of airglow observations from Mt. Haleakala, Hawaii. The airglow scan observations were made with narrowband filters of OI 5577 ¿ and OI 6300 ¿ for 164 nights in the period of April 1965 through October 1968. The OI 6300 emissions are produced mostly via recombination of O2+ in the F region, whereas the OI 5577 emissions are generated both in the E and F regions. The database has unique significance, since it covers more than three years of observations in the 1960s when there was no other program that systematically monitored ionospheric airglows. We find disturbances in the OI airglow brightness, from which we constructed projected maps of airglow distributions at the F region altitude. The projected maps clearly show wavelike disturbances whose crests are mostly aligned along a north--south direction, structures seen even in the raw scan data. The disturbances were found exclusively in the southerly azimuth toward the equator, implying that they are one of the equatorial ionospheric irregularities, known as equatorial spread F (ESF). The ESF disturbances occurred 19 nights out of a total of 161 nights of azimuth-scanning observations with a maximum in September. The disturbances seem to arise regardless of geomagnetic activities. The seasonal variation of the occurrence is consistent with recent analyses of satellite data in which ESF is suggested to be caused by gravity waves from the troposphere, where they are generated by strong convection in intertropical convergence zone. |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
|
Keywords
Ionosphere, Ionospheric irregularities, Ionosphere, Wave propagation, Ionosphere, Equatorial ionosphere, Ionosphere, Ionospheric disturbances, Meteorology and Atmospheric Dynamics, Waves and tides |
|
Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
|
|
|