Propagation of medium scale traveling ionospheric disturbances at different latitudes and solar cycle conditions

Abstract

[1] In this work, an extension in latitude range and time span with respect previous studies on Medium Scale Traveling Ionospheric Disturbances (MSTID) propagation, is presented. So far they have been basically studied at mid latitude and for limited periods (less than few years) at solar maximum conditions. This extension has been possible due to the availability of local Global Positioning System (GPS) networks at mid-north hemisphere (California), mid-south hemisphere (New Zealand), high and low latitudes (Alaska and Hawaii), for the last 13, 11, 7 and 4 years respectively. Optimal algorithms specially suitable for mass data processing have been used, such as the Single Receiver Medium Scale Traveling Ionospheric activity index (SRMTID) and the phase difference method for MSTID propagation estimation. The results reveal that several of the main MSTID climatological trends at mid latitude are also shared at low and high latitude, also modulated in intensity also by the Solar Cycle. This is the case for local fall/winter day-time equatorward propagated MSTIDs with typical velocities and wavelengths of 150-250 m/s and 100-300 km respectively. Moreover the comparison of MSTID propagation estimation using different techniques, and their implications in terms of potential origins of MSTIDs, are also discussed.

Traveling ionospheric disturbances observed at South African midlatitudes during the 29–31 October 2003 geomagnetically disturbed period

“…the total electron content (TEC). TEC measurements from ground based GPS network provide a powerful tool to study the time evolution of the ionosphere over a large region or on a global scale, see for example Chartier et al (2012), Hernandez-Pajares et al (2012), Tsugawa et al (2007), and Tsai et al (2001).…”

Sources and characteristics of medium‐scale traveling ionospheric disturbances observed by high‐frequency radars in the North American sector

“…They typically have periods of 15-60 min, horizontal wavelengths of several hundred kilometers, and horizontal phase speeds of less than approximately 300 m s −1 [e.g., Ogawa et al, 1987;Samson et al, 1990]. MSTIDs have been extensively studied in both the high-latitude and midlatitude regions [e.g., Evans et al, 1983;Waldock and Jones, 1986;Ogawa et al, 1987;Samson et al, 1989Samson et al, , 1990Bristow et al, 1994Kotake et al, 2007;Ishida et al, 2008;Hernández-Pajares et al, 2012;Grocott et al, 2013;Frissell et al, 2014]. MSTIDs have been extensively studied in both the high-latitude and midlatitude regions [e.g., Evans et al, 1983;Waldock and Jones, 1986;Ogawa et al, 1987;Samson et al, 1989Samson et al, , 1990Bristow et al, 1994Kotake et al, 2007;Ishida et al, 2008;Hernández-Pajares et al, 2012;Grocott et al, 2013;Frissell et al, 2014].…”

Medium-scale traveling ionospheric disturbances over Taiwan observed with HF Doppler sounding

“…MSTIDs may affect radio astronomical measurements and the accuracy of global navigation satellite systems (GNSSs) (Hernández-Pajares et al 2012). Hence, including their parametrization into atmospheric models is required (Liu et al 2014).…”