Diurnal, seasonal and solar activity pattern of ionospheric variability from Irkutsk Digisonde data

Meteorological effects of ionospheric disturbances from vertical radio sounding data

“…Such a behavior agrees closely with the GWs activity at the stratospheric and mesospheric heights (Alexander et al, 2010), the seasonal distribution of GW events in the lower ionosphere (Oleynikov et al, 2007), and the seasonal distribution of wavelike disturbances at the F2 layer heights . The relative TID variability did not show a clear increase with the geomagnetic/solar activity (Ratovsky et al, 2014a). This result was surprising, because authors expected an enhancement of the GWs activity during the periods of geomagnetic storms considering heating processes in the lower auroral ionosphere as sources of GWs (Hocke and Schlegel, 1996).…”

“…However, note that MLS aboard the EOS-Aura spacecraft provides two measurements per day into ascending and descending node orbits over the given region; that is why we cannot use these data to analyze the time variations in temperature less than 12 hours (Schwartz et al, 2008). Ionospheric F2 layer variability over Irkutsk was thoroughly studied from the 2003-2012 dataset of the Irkutsk DPS-4 digisonde in (Ratovsky et al, 2014a). Authors obtained the diurnal, seasonal, and solar activity pattern of the NmF2 variability for both high-and low-frequency parts of the variability.…”

“…Thus, studying meteorological effects in the ionosphere is still relevant to understand the coupling of processes in the atmosphere-ionosphere system. Ratovsky et al (2014a) presented the first analysis results for the seasonal dependence of the high-frequency part (periods from 0.5 to 6 hrs) of the F2 peak density (NmF2) variability from the Irkutsk digisonde data. The previous results of JS effects on variations in NmF2 obtained with the Irkutsk ionosonde over 2008-2010 were presented in (Chernigovskaya et al, 2014b).…”

Studying atmospheric and ionospheric variabilities from long‐term spectrometric and radio sounding measurements

“…Both the daytime and nighttime seasonal patterns of the day‐to‐day variability agree closely with the seasonal variations of the total relative variability at Irkutsk reported by Ratovsky et al . [] due to the fact that the day‐to‐day variability provides the main contribution to the total relative variability. The nighttime seasonal behavior of the day‐to‐day variability agrees qualitatively with those of the total relative variability for midlatitude stations reported by Rishbeth and Mendillo [] and Araujo‐Pradere et al .…”

“…Ratovsky et al . [] considered the following factors affecting the seasonal behavior of the ionospheric variability: (1) the photochemical control seasonal variations, (2) the geomagnetic activity seasonal variations, and (3) the atmospheric activity seasonal variations.…”