Characterization and Modeling of the Medium Scale Traveling Ionospheric Disturbances (MSTIDs) in High-Frequency radar observations

One of the interesting phenomena in the earth’s ionosphere is medium-scale traveling ionospheric disturbances (MSTIDs), which are wave-like propagating ionospheric density disturbances driven by atmospheric gravity waves and electrodynamic processes. The MSTIDs typically have a time period of 15-60 min, phase velocities of 100-300 m/sec, and wavelengths between 200 and 800 km. The characterization and source analysis of MSTIDs is an active frontier topic of research. In this work, we seek to understand the signatures of the MSTIDs as detected in the vertical Ionosonde Ionogram observations. To reproduce these signatures, and to test the applicability of the Hooke model for representing MSTID dynamics, we perform ray tracing through an MSTID-disturbed ionospheric model. The Hooke model assumes the atmospheric gravity waves as the perturbing mechanism to represent the TID disturbances. The wave parameters in the Hooke model are taken from the airglow observations of the MSTIDs in the North-American sector. We employ PyLAP ray-tracing package – a Python implementation of MATLAB ray-tracing toolbox PHaRLAP – to model the effects of MSTIDs on High-Frequency (HF) radio wave propagation.