Local and Regional Ionospheric Disturbances During Meteorological Disturbances

Geomagnetism and Aeronomy - Observations of atmospheric and ionospheric parameters during meteorological disturbances in November–December 2010 are analyzed. It is shown that a sharp change...     

Vertical Propagation of Acoustic-Gravity Waves from Atmospheric Fronts into the Upper Atmosphere

Izvestiya, Atmospheric and Oceanic Physics - The empirical approximations of atmospheric pressure-field oscillations were constructed based on observational data on atmospheric pressure variations...     

Modeling the Effect of Mesospheric Internal Gravity Waves in the Thermosphere and Ionosphere During the 2009 Sudden Stratospheric Warming

The results of numerical experiments on the modeling of thermospheric and ionospheric disturbances under conditions of sudden stratospheric warming are presented to study the possible mechanisms of such disturbances. Local disturbances caused by a planetary wave with zonal wave number s = 1 and internal gravity waves (IGWs) propagating from the disturbed region in the stratosphere are taken into account as sources of disturbances. It is shown that the inclusion of an additional source of thermospheric disturbances caused by mesospheric variations of atmospheric parameters with IGW periods over the region of sudden stratospheric warming leads to significant changes in the parameters of the thermosphere and ionosphere, including a change in the global structure of the distributions of the gas components of the thermosphere and a shift in maximum concentrations of atomic oxygen to low latitudes of the Southern Hemisphere; there is an increase in the mean values, the diurnal and semidiurnal variations of the ion concentration in the F region of the ionosphere. These features of changes in the parameters of the thermosphere and ionosphere occurred with insignificant disturbances of tidal variations in the thermosphere.     

Ionospheric Disturbances during Meteorological Storms

Geomagnetism and Aeronomy - Ionospheric disturbances during meteorological storms in the Kaliningrad region with a wind amplification of 8 points or higher on the Beaufort scale for the period...     

Ionospheric irregularities in periods of meteorological disturbances

The results of observations of the total electron content (TEC) in periods of storm disturbances of meteorological situation are presented in the paper. The observational results have shown that a passage of a meteorological storm is accompanied by a substantial decrease in values of TEC and critical frequencies of the ionospheric F2 region. The decreases in values of these ionospheric parameters reach 50% and up to 30% in TEC and critical frequency of the F2 layer, respectively, as compared to meteorologically quiet days. Based on qualitative analysis, it is found that the processes related to formation of local regions of thermospheric heating due to a dissipation of AGW coming into the upper atmosphere from the region of the meteorological disturbance in the lower atmosphere are a possible cause of these ionospheric disturbances.     

Features of Variations in the F2-Layer Critical Frequency During the Sudden Stratospheric Warnings of 1966–2009 According to Data from Kaliningrad and Irkutsk Stations

Geomagnetism and Aeronomy - A study of the wave changeability in the F2-layer critical frequency over Kaliningrad (54.6° N, 20° E) and Irkutsk (53° N, 103° E) stations during...