Statistical study of medium-scale traveling ionospheric disturbances using SuperDARN Hokkaido ground backscatter data for 2011

Abstract

We describe an automated technique to determine parameters of traveling ionospheric disturbances (TIDs) using the Super Dual Auroral Radar Network (SuperDARN) high frequency (HF) radar data. The technique is based on the analysis of minimum ground backscatter range variations corresponding to different radar beams. Using this technique, we processed the SuperDARN Hokkaido radar data for 2011 and revealed statistical distributions of medium-scale TID (MSTID) azimuth and apparent horizontal velocity. We found four peaks with a distinct diurnal and seasonal dependence in the MSTID azimuth occurrence rate distributions. Northeast MSTID azimuths (20°to 50°) are typical of the summer and equinox morning hours; southeast azimuths (100°to 140°) prevail in the winter daytime; southwest azimuths (190°to 220°) are typical mostly in the summer and equinox nighttime and in the equinox evening; northwest azimuths (280°to 320°) are typical of the summer daytime and evening. The apparent horizontal velocities are generally within the 100 to 160 m/s range. The obtained results agree well with earlier studies by other researchers. However, there are also certain differences. The summer daytime northwestward MSTIDs are not indicated in the earlier studies. The nighttime horizontal velocities are 1.5 to 2 times higher than those in the daytime. Furthermore, winter velocity values are about 1.5 times higher than those in other seasons. These differences might be associated with the peculiarities of the data recorded by different facilities, or the features of the processing techniques, and require further investigation for their interpretation.

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

“…8. Oinats et al (2015) also observed southwest azimuths in the summer, equinox nighttime, and equinox evening and northwest azimuths in summer daytime and evening; similar observations are not found in our observations from Taiwan. Otsuka et al (2013) studied MSTIDs over Europe using GPS in 2008.…”

“…They found that a majority of MSTIDs propagated equatorward in this period, which is similar to our observations. Oinats et al (2015) studied MSTIDs using the Super Dual Auroral Radar Network in Hokkaido, i.e., a location that is more poleward than Taiwan. Northeastward propagating MSTIDs were typical for summer and equinox.…”

“…Recently, MSTIDs have been studied statistically in many places worldwide using various techniques (Frissell et al 2014(Frissell et al , 2016Fukushima et al 2012;Grocott et al 2013;He et al 2004;Ichihara et al 2013;Ishida et al 2008;Klausner et al 2009;Kotake and Otsuka 2007;Medvedev et al 2013;Oinats et al 2015Oinats et al , 2016Otsuka et al 2011Otsuka et al , 2013Shiokawa et al 2003Shiokawa et al , 2009. In this study, we present observations of MSTIDs' horizontal velocities over Taiwan using HF Doppler sounding.…”

Statistical characteristics of medium-scale traveling ionospheric disturbances revealed from the Hokkaido East and Ekaterinburg HF radar data

“…The steps of data processing and analysis are almost the same as described in Oinats et al (2015). Here, we list them briefly and emphasize the differences between present and previous techniques.…”

Diurnal and seasonal behavior of the Hokkaido East SuperDARN ground backscatter: simulation and observation

“…In case of the absence of the elevation measurement, the effective height is usually assumed to be fixed at a specific value (Bristow et al 1994;Grocott et al 2013;Oinats et al 2015), or some empirical height models could be used Yeoman et al 2008). Figure 2a shows the dependence of the effective reflection height calculated using Eq.…”