Modeling the Arecibo nighttime F 2 layer: 2. Ionospheric gradients

摘要: The servo model is extended and used to fit horizontal gradients in the F2 layer height density estimate zonal Pedersen current its meridional gradient. Horizontal were measured from Arecibo Observatory during following five nights: August 16-17 17-18, 1982; October 4-5, 5-6, 9-10, 1983. are driven by nonzero gradients, which applied as needed peak. gradient peak accurately reproduced; calculated self-consistently model. divergence of can be deduced when flows zonally found differ zero. This a consequence current. Expressions derived for Hall curl presence ionospheric gradients. vertical vorticity F region determined radar optical measurements mass spectrometer/incoherent scatter (MSIS) neutral densities. Both plasma motions generate equally expected dynamo. velocity produce more than conductance perpendicular-north drift (∂zυ⊥N) dominant term drives two shears that cause vorticity. Geometrical factors increase about 13% over causes anticorrelation between former shear generally follow each other, have opposing vorticities large uncertainties. nighttime may irrotational or constant Large occur conjunction with observed descents height. interpreted due midnight pressure bulge at low latitudes. Short-period gravity waves meteorological origin ruled out they not limited their ability reach heights. harmonic analysis obtain wind largely unaffected spatially uniform accelerations. Therefore spatial variations winds unlikely temporal variations.