High-midlatitude ionosphere response to major stratospheric warming

Abstract

This study investigates the impact of dynamical processes in the neutral atmosphere on the high-midlatitude ionosphere during two sudden stratospheric warming (SSW) events. For this purpose, the reanalysis meteorological data of the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and UK Met Office (UKMO) were used in addition to that from the high-midlatitude chain of Russian ionosonde stations. The results show that the ionospheric response to the SSW events at high-midlatitudes depends on the position of the ionosonde stations relative to the stratospheric circulation pattern. Two well-pronounced effects were detected in this study. The first effect, observed in January 2009, was a negative effect in critical frequency (f o F2) and a positive effect in F2 layer maximum (h m F2) above the border of a stratospheric cyclone and an anticyclone with northward flow direction. During a 6-day period, the ionosphere exhibited a sharply inhomogeneous longitudinal structure when ionosondes, displaced at a longitude of approximately 20°, showed differences of approximately 1 MHz in f o F2 and more than 50 km in h m F2. The second feature, which was clearly observed in January 2013, implied a positive effect in f o F2 up to approximately 2.5 MHz and a negative effect in h m F2 at approximately 10 km above the center of the stratospheric cyclone. We conclude that these effects were caused by upward transport of molecular gas to the lower thermosphere for the first case and a pulldown forcing of molecular species above the low-pressure zone inside the cyclone for the second case. Changes in the O + /N 2 ratio in the lower thermosphere altered the O + recombination rate and the corresponding variations of ionosphere parameters.

Comprehensive study of disturbances of the neutral atmosphere and ionosphere parameters over Eastern Siberia during the 2013 January major sudden stratospheric warming

“…We observed such a pattern after January 10, when a sharp rise in the ion temperature occurred. This result agrees with that of Shpynev et al (2015).…”

“…It is known, that solar activity variations can cause ionospheric disturbances. However, Polyakova et al (2014) and Shpynev et al (2015) revealed different behavior of the ionospheric response to the 2013 SSW at different observation points. Thus, variations in ionospheric parameters cannot be explained only by the rising solar activity.…”

“…Ionospheric response to the 2013 SSW was investigated in a number of works (Goncharenko et al, 2013, Polyakova et al, 2014Shpynev et al 2015). Goncharenko et al (2013) revealed that anomalous variations in vertical ion drift measured at Jicamarca (12°S, 77°W) were observed for over 40 days.…”

“…They reported strong perturbations in the total electron content (TEC) that reached 100% of the background value. Shpynev et al (2015) analyzed ionospheric response to the 2009 and 2013 SSWs by using the data from the high-midlatitude chain of the Russian ionosonde stations. They showed that the intensity and sign of SSW effects depend on the observation point position relative to a stratospheric circulation zone.…”

Influence of January 2009 stratospheric warming on HF radio wave propagation in the low-latitude ionosphere

“…For this event there are continuous measurements made at the global network of incoherent scatter radars for eleven days, as well as an extensive array of ionosonde observations. Ionospheric effects observed in Russian Asia during the SSW event in winter of [2008][2009] have been discussed in [Polyakova et al, 2014;Shpynev et al, 2015]. Global and mid-latitude ionospheric responses to this event have also been repeatedly studied [Yue et al, 2010;Pancheva and Mukhtarov, 2011;Bessarab et al, 2012;Fagundes et al, 2015].…”