The large amount of data that are available for ionospheric studies using the GPS TEC method, as well as the need to take into account complex atmospheric dynamics, create certain difficulties in automating the process of searching and recognizing traveling ionospheric disturbances generated by different sources. To automate the process of detecting wave disturbances, numerical criteria for assessing the level of the wave disturbance signal were proposed. The signal-to-noise ratio calculated by the proposed method was used as one of such criteria. This work contains a description of the developed software system that implements the proposed methodology and allows the loading of RINEX files and processing, analyzing, and visualizing total electron content data.

Based on the data of 35-year (1987–2021) measurements of magnetospheric electron fluxes with energy > 2 MeV in geostationary orbits, solar wind speed and geomagnetic activity, a catalog of electron flux enhancements was compiled in which the electron fluence exceeds 108 cm–2∙sr–1∙day–1. The epoch superposition method performed using the GOES-13 spacecraft data shows that large electron flux enhancements are preceded by a significant increase in the solar wind velocity and the Ap index of geomagnetic activity, and immediately before the increase the relativistic electron flux decreases. For the events of the catalog, the average characteristics of electron flux enhancements and parameters of the interplanetary and near-Earth medium were calculated: the mean values of the diurnal and total fluences during an event and the average duration of electron enhancements. The average duration of the electron flux enhancement is 5 days, and the maximum duration is 24 days. Based on the calculated mean values of the electron fluences, solar wind velocity, and Ap-index of geomagnetic activity on the day of electron enhancement and on previous days, a typical behavior of these parameters during and before an electron flux enhancement was obtained. The average characteristics of electron flux enhancements and the parameters of interplanetary and near-Earth medium are calculated before large electron flux enhancements, when the fluence exceeds 3∙108, 5∙108 and 109 particles∙cm–2∙sr–1∙day–1, respectively. It is shown that the greater the increase in solar wind velocity and geomagnetic activity the larger the subsequent electron flux enhancement.

Проведены расчеты температурного баланса и орбитальной эволюции силикатных и графитовых пылевых частиц в области сублимации около белого карлика G29-38. Темп сублимации (испарения) задается температурой нагрева пылевых частиц в зависимости от расстояния до звезды, параметров материала и радиусов пылинок в пределах от 0.01 до 100 мкм. Учитывалось влияние давления радиации и эффекта торможения Пойнтинга-Робертсона на динамику пыли. В расчётах предполагается, что частицы срываются с родительских тел, движущихся по круговым орбитам. Наши расчёты показали, что гранулы могут образовать резкую границу области сублимации на определённом расстоянии от звезды в зависимости от материала частиц. Если около звезды с параметрами, близкими к G29-38, преобладают силикатные частицы, то внутренняя граница зоны сублимации для крупных гранул радиусами s > 5 мкм образуется на расстоянии около 45 Rstar ≈ 0.6Rsun. Малые силикатные частицы радиусами s < 0.1 мкм не могут приблизиться к звезде на расстояние ближе 300Rstar ≈ 4Rsun из-за быстрого испарения. Если преобладают графитнокарбоновые частицы, то граница зоны сублимации для частиц радиусами s > 0.2 мкм возможна на расстоянии около 12.5 Rstar ≈ 0.16 Rsun. Карбоновые частицы радиусами s < 0.1 мкм испаряются за пределами расстояния 0.6Rsun. Если согласно Rearch (2009) температура пыли Т = 950К, то наблюдаемая часть пылевого облака (диска) соответствует расстоянию от звезды около 1Rsun, где могут существовать только крупные силикатные частицы радиусами s > 5 мкм или карбоновые радиусами s > 0.5 мкм.

Abstract. Ground-based observations show a phase shift in semi-annual variation of excited hydroxyl (OH∗) emissions at mid-latitudes (43∘ N) compared to those at low latitudes. This differs from the annual cycle at high latitudes. We examine this behaviour by utilising an OH∗ airglow model which was incorporated into a 3D chemistry–transport model (CTM). Through this modelling, we study the morphology of the excited hydroxyl emission layer at mid-latitudes (30–50∘ N), and we assess the impact of the main drivers of its semi-annual variation: temperature, atomic oxygen, and air density. We found that this shift in the semi-annual cycle is determined mainly by the superposition of annual variations of temperature and atomic oxygen concentration. Hence, the winter peak for emission is determined exclusively by atomic oxygen concentration, whereas the summer peak is the superposition of all impacts, with temperature taking a leading role.