The main results of the long-term measurements of the neutral atmosphere parameters by the artificial periodic irregularities techniques

Artificial periodic irregularities in the high‐latitude ionosphere excited by the HAARP facility

“…[, , ]. The most recent experiments on the API formation were carried out using similar pumping and probing waves [ Bakhmet ' eva et al ., , , ; Bakhmetieva and Belikovich , , ; Grigoriev et al ., ; Tolmacheva et al ., ].…”

“…In this paper we will not discuss in detail the methodology for determining of the neutral temperature and density. It is given in detail in the monographs [ Belikovich et al ., ] and [ Tolmacheva et al ., ]. We show only the way to determine some parameters that we plan to introduce in the next publication.…”

“…Analyses of the height–time dependence of the amplitude and the phase of the API echoes make it possible to get information on a number of ionospheric parameters [ Bakhmetieva et al ., ; Belikovich et al ., ; Tolmacheva et al ., ]: (i) altitude distribution of the electron number density, including the interlayer E–F valley (altitudes 60–250 km), (ii) temperature and density of the atmosphere at the E region (100–130 km); (iii) velocity of the vertical motion in the D and E regions (60–130 km); (iv) turbulent velocity near the turbopause and its altitude (90–110 km); (v) relative number density of negative ions of oxygen and concentrations of atomic oxygen and excited molecular oxygen in the 1 Δ g state in the D region (60–90 km), the lower boundary of the region enriched by the atomic oxygen; (vi) ion composition of the sporadic E layer (85–130 km); and (vii) electron and ion temperatures in the F region (200–300 km). Some of these results are presented in the monograph [ Belikovich et al ., ] and in recent papers [ Grigoriev et al ., ; Bakhmetieva et al ., ; Tolmacheva et al ., ]. APIs allows one to (i) determine reliably the parameters of internal gravity waves and their spectral characteristics; (ii) study the inhomogeneous structure of the lower ionosphere, including the stratification of the regular E layer; (iii) detect weak sporadic layers of ionization, which are undetectable by regular ionosonde; and measure additional layers of the electron density profiles from the lower part of the D region to the altitude of the F layer maximum.…”

“…Results of measurements of the N(h) profile in the E region are presented in Belikovich et al [2002Belikovich et al [ , 2006Belikovich et al [ , 2008. The most recent experiments on the API formation were carried out using similar pumping and probing waves [Bakhmet'eva et al, 2005[Bakhmet'eva et al, , 2010[Bakhmet'eva et al, , 2013Belikovich, 2007, 2008; Grigoriev et al, 2013;Tolmacheva et al, 2015].…”

“…Currently, API technique is used as method to study the ionosphere and neutral atmosphere. Results of these studies and the theory of API formation and decay are summarized in the monograph [ Belikovich et al ., ] and papers [ Bakhmet ' eva et al ., ; Bakhmetieva and Belikovich , , ; Grigoriev et al ., ; Tolmacheva et al ., ]. APIs were observed at the heating facilities at Arecibo [ Feier et al ., ], High Power Auroral Stimulation (HIPAS) [ Djuth et al ., ], European Incoherent Scatter (EISCAT) [ Rietveld et al ., ; Rietveld and Goncharov , ; Vierinen et al ., ], and High Frequency Active Auroral Research Program (HAARP) [ Hysell et al ., ; Grach et al ., ].…”