Statistical scintillation indices in polar ionospheric climatology

Abstract

It has been established that polar cap patches are capable of triggering phase scintillation via various convective instabilities such as Gradient Drift, Gravitational Interchange, Current Convective, and Kelvin-Helmholtz Instabilities coupled with turbulent plasma processes in the cold and warm approximation. These multiple instabilities provide a qualitative density peaking mechanism which ultimately leads to the formation of highly dense and coherent nonlinear structures such as polar patches and auroral blobs at high latitudes. It is important to note that the nonlinear evolution of these polar patches/blobs and their associated plasma number density inhomogeneities are primarily controlled by dominant magnetospheric (inertial) or ionospheric (collisional) current systems. Moreover, intense observational studies on the trans-polar movement of these polar patches/blobs and their associated morphology further classify these structures as Type 1 and Type 2 blobs depending upon their density estimates and ionisation sources. In this study, a correlation between inherent polar patches plasma parameters and phase scintillation metrics is discussed in terms of Total Electron Content (TEC) and ROTI measurements at a localised region Ny-Alesund [78.93◦N, 11.86◦E], Svalbard which is more sensitive to the polar patch mobilisation driven by dayside polar cusp dynamics. Moreover, it is concluded that phase scintillation studied in terms of TEC and ROTI local estimations could be used as proxies for the polar ionosphere.