Earth-printshttps://www.earth-prints.orgThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Thu, 15 Apr 2021 10:13:17 GMT2021-04-15T10:13:17Z5021Correlation between scintillation indices and gradient drift wave amplitudes in the northern polar ionospherehttp://hdl.handle.net/2122/5132Title: Correlation between scintillation indices and gradient drift wave amplitudes in the northern polar ionosphere
Authors: Burston, R.; Astin, I.; Mitchell, C.; Alfonsi, Lu.; Pedersen, T.; Skone, S.
Abstract: A model is developed of the gradient drift instability growth rate in the north polar cap ionosphere, utilizing a novel approach employing an ionospheric imaging algorithm. The growth rate values calculated by this model are in turn used to estimate how the
amplitudes of actual gradient drift waves vary over time as the plasma drifts and the
growth rates change with time. Ionospheric imaging is again used in order to determine
plasma drift velocities. The final output from the model is in turn used to assess the
linear correlation between the scintillation indices S4 and σØ recorded by several GPS L1
band scintillation receivers stationed in the north polar cap and mean gradient drift wave amplitudes. Four separate magnetic storm periods, totaling 13 days, are analyzed in this way. The results show weak but significant linear correlations between the mean wave amplitudes calculated and the observed scintillation indices at F layer altitudes.
Tue, 21 Jul 2009 00:00:00 GMThttp://hdl.handle.net/2122/51322009-07-21T00:00:00ZTurbulent times in the northern polar ionosphere?http://hdl.handle.net/2122/7017Title: Turbulent times in the northern polar ionosphere?
Authors: Burston, R.; Astin, I.; Mitchell, C.; Alfonsi, Lu.; Pedersen, T.; Skone, S.
Abstract: A model is presented of the growth rate of turbulently generated irregularities in
the electron concentration of northern polar cap plasma patches. The turbulence is
generated by the short‐term fluctuations in the electric field imposed on the polar cap
ionosphere by electric field mapping from the magnetosphere. The model uses an
ionospheric imaging algorithm to specify the state of the ionosphere throughout. The
growth rates are used to estimate mean amplitudes for the irregularities, and these mean
amplitudes are compared with observations of the scintillation indices S4 and s by
calculating the linear correlation coefficients between them. The scintillation data
are recorded by GPS L1 band receivers stationed at high northern latitudes. A total of
13 days are analyzed, covering four separate magnetic storm periods. These results are
compared with those from a similar model of the gradient drift instability (GDI) growth
rate. Overall, the results show better correlation between the GDI process and the
scintillation indices than for the turbulence process and the scintillation indices. Two
storms, however, show approximately equally good correlations for both processes,
indicating that there might be times when the turbulence process of irregularity formation
on plasma patches may be the controlling one.
Fri, 30 Apr 2010 00:00:00 GMThttp://hdl.handle.net/2122/70172010-04-30T00:00:00Z