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Climatology Of Early Night Equatorial Spread F Over Jicamarca, N. P. Chapagain, Bela G. Fejer
Climatology Of Early Night Equatorial Spread F Over Jicamarca, N. P. Chapagain, Bela G. Fejer
Bela G. Fejer
[1] We use radar observations from 1996 to 2006 to study the climatology of postsunset equatorial 3-m spread F irregularities over Jicamarca during all seasons. We show that the spread F onset times do not change with solar flux and that their onset heights, which occur near the altitude of the evening F region velocity vortex, increase linearly from about 260 to 400 km from solar minimum to solar maximum. Higher onset heights generally lead to stronger radar echoes. During the equinox, spread F onset occurs near vertical drift evening reversal times, while during the December solstice, they occur near …
Climatology Of F Region Zonalplasma Drifts Over Jicamarca, Bela G. Fejer, J. R. Souza, A. S. Santos, A. E. Costa Pereira
Climatology Of F Region Zonalplasma Drifts Over Jicamarca, Bela G. Fejer, J. R. Souza, A. S. Santos, A. E. Costa Pereira
Bela G. Fejer
[1] We use extensive incoherent scatter radar observations made at the Jicamarca Radio Observatory between 1970 and 2003 to study and model empirically the equatorial zonal plasma drifts near the F region peak using Bernstein polynomials as base functions. Our quiet-time model results confirm that the daytime drifts are westward and are nearly season and solar cycle independent. The nighttime drifts are eastward, have larger magnitudes, and increase strongly with solar flux, particularly near equinox and December solstice. Enhanced geomagnetic activity drives small eastward perturbation drifts during the day and much larger westward disturbance drifts at night. The nighttime drift …
Climatology And Latitudinal Gradients Of Quiet-Timethermospheric Neutral Winds Over Millstone Hill From Fabry-Perot Interferometermeasurements, J. T. Emmert, Bela G. Fejer, D. P. Sipler
Climatology And Latitudinal Gradients Of Quiet-Timethermospheric Neutral Winds Over Millstone Hill From Fabry-Perot Interferometermeasurements, J. T. Emmert, Bela G. Fejer, D. P. Sipler
Bela G. Fejer
[1] Midlatitude nighttime thermospheric neutral winds are strongly dependent on season, solar activity, and latitude. We use an extensive database of wind measurements made during 1989–2001 by the Millstone Hill Fabry-Perot interferometer to study the detailed climatology of quiet time neutral winds near an altitude of 250 km. To facilitate the analysis of these data, we develop a local time, day-of-year, solar flux, and latitude-dependent empirical model, with the latitude dependence obtained by considering north looking and south looking observations separately. Our results show that the zonal winds are predominantly eastward after dusk and westward before dawn, with the strongest …
Climatology And Storm Time Dependence Ofnighttime Thermospheric Neutral Winds Over Millstone Hill, Bela G. Fejer, J. T. Emmert, D. P. Sipler
Climatology And Storm Time Dependence Ofnighttime Thermospheric Neutral Winds Over Millstone Hill, Bela G. Fejer, J. T. Emmert, D. P. Sipler
Bela G. Fejer
[1] We use 630.0 nm nightglow Fabry-Perot measurements over Millstone Hill from 1989–1999 to study the climatology and storm time dependence of the midlatitude thermospheric winds. Our quiet time wind patterns are consistent with results from earlier studies. We determine the perturbation winds by subtracting from each measurement the corresponding quiet time averages. The climatological zonal disturbance winds are largely independent of season and solar flux and show large early night westward and small late-night eastward winds similar to disturbance ion drifts. The meridional perturbation winds vary strongly with season and solar flux. When the solar flux is low, the …
Climatology Of Mid- And Low-Latitude F Region Disturbance Winds Measured By Windii, J. T. Emmert, Bela G. Fejer, C. G. Fesen, G. G. Shepherd, B. H. Solheim
Climatology Of Mid- And Low-Latitude F Region Disturbance Winds Measured By Windii, J. T. Emmert, Bela G. Fejer, C. G. Fesen, G. G. Shepherd, B. H. Solheim
Bela G. Fejer
No abstract provided.