Abstracted/indexed

In this study, the performance of BDS B1 frequency standard point positioning during different classes of geomagnetic storms is investigated for the first time. The main finding is that the point positioning accuracy was degraded during the storms. The probability of the extrema in the statistics of positioning errors during strong storms is the largest, followed by moderate and weak storms. The positioning accuracy for storms of a similar class is found not to be at the same level.

We presented sharp descent in proton fluxes is accompanied by the corresponding depression of SYM-H index, with a one-to-one correspondence, regardless of the storm intensity in our previous work [Xu et al., 2019]. This paper is a further study of the possible mechanisms, and to quantitified evaluate the effect of full adiabatic changes. Inner belt is not very stable as previous announced especially for the out zone of the inner belt. It is necessary to survey characteristics of protons.

Kelvin-Helmholtz billows (KHB) have been investigated in the Atmospheric Boundary layer (ABL) using Mono-static SODAR (Sound Detection And Ranging) first time over the capital region Delhi of India. About ninety cases of KHBs observed in SODAR echograms from March 2019 to November 2019 in the ABL. KH billows are a primary cause of mixing in stably stratified conditions and hence have been studied widely by researchers by using ground-based and remote sensing methods.

In this work we present the first analytical magnetosheath plasma flow model for the space environment around Mercury. The proposed model is relatively simple to implement and provides the possibility to trace the flowlines inside the Hermean magnetosheath. It can help to determine the the local plasma conditions of a spacecraft in the magnetosheath exclusively on basis of the upstream solar wind parameters.

This paper presents analysis of high-resolution optical and radar observations of a phenomenon called Fragments of Aurora-like Emission (FAEs), observed close to aurora in the high Arctic. The observations suggest that FAEs are not caused by high energy electrons or protons entering the atmosphere along Earth's magnetic field, and are therefore not aurora. The speeds of the FAEs and their internal dynamics were measured and used to evaluate theories for how the FAEs are produced.

It has been supposed so far that the earth ionosphere is a passive load in changing weather in space (space weather) during the course of energy transfer from the Sun to the Earth. In this report, we present a new idea that ionosphere is not merely a load in the Sun-Earth system but takes the initiative in space weather.

In this paper, we propose a new explanation to the formation of Shouder-like based on Test Particle Model. The simulation reproduce three Shoulder in a substorm case. The physical explanation of Shoulder formation is not yet understood. The paper suggest that the physical mechanism of Shoulder formation is the result of plasma extrusion in the predawn sector, caused by outer plasmasphere drifts radial outward and rotates faster. the single or double Plumes appear derives from the 279 Shoulder.

The collisionless shocks are very complicated and important field of nowadays researches. We used the data measured by the plasma spectrometer BMSW (Bright Monitor of Solar Wind) to investigate variations of parameters of twice-ionized helium ions He⁺⁺ in the solar wind during the interplanetary shock passage. It was shown that the changes of He⁺⁺ abundance are depended of interplanetary shock parameters.

Plasma waves are an integral part of cometary physics, as they facilitate the transfer of energy and momentum. From intermediate to strong activity nonlinear asymmetric plasma and magnetic field enhancements dominate the inner coma of 67P/CG. We present a statistical survey of these structures from December 2014 to June 2016, facilitated by Rosetta's unprecedented long mission duration. Using a 1D-MHD model we show that they can be described as a combination of nonlinear and dissipative effects.

We investigate the delayed ionospheric response using the observed and CTIPe model simulated TEC against the solar EUV flux. The ionospheric delay estimated using model simulated TEC is in good agreement with the delay estimated for observed TEC. The study confirms the model capabilities to reproduce the delayed ionospheric response against the solar EUV flux. Results also indicate that the average delay is higher in the Northern Hemisphere as compared to the Southern Hemisphere.

This study analyze the climatology of ionosphere over Nepal based on GPS derived VTEC during years 2008 to 2018. The study illustrates the diurnal, monthly, annual, seasonal and solar cycle variations of VTEC. The results clearly revel the presence of equinoctial asymmetry in TEC in maximum phases in 2014 followed by descending, ascending and minimum phases. The winter anomalies are noticed during increasing and maximum phases of the solar cycle 2011 and 2014 from almost all stations considered.

The polar mesospheric summer echoes (PMSE) are very strong radar echoes observed in the frequency range of 2 MHz up to 1 GHz. Such radar echoes are attributed to the ice clouds formed in the mesosphere and are widely believed to link to global climate change. PMSEs are coherent echoes produced by plasma density fluctuations at half the radar wavelengts. This paper investigates the unresolved problem of short durability of plasma fluctuations at smaller wavelengths in upper atmospheric physics.

This study of the possibility of low energy-PIXE (3 MeV) applied to the higher Z elements of high grade metamorphic rocks, including Si (Li) detector is exactly valid or not for future studies. The experimental factors like incident energy, production cross sections, detector etc, behind the important high Z of matrix rocks by LE-PIXE are discussed and also the modifications which will be required at high Z elements like HE-PIXE or complementary methods.

The study presents an approach to compare infrasound data and simulated microbarom soundscapes in multiple directions. Data recorded during 2014–2019 at the IS37 in Norway were processed and compared to model results in different aspects: directional distribution, signal amplitude, and ability to track atmospheric changes during extreme events. The results reveal good agreement between model and data. The approach has potential for near-real-time atmospheric and microbaroms diagnostics.

Ground-based observations show a phase shift in semi-annual variation of excited hydroxyl emissions at mid-latitudes compared to those at low latitudes. This differs from the annual cycle at high latitudes. We found that this shift in the semi-annual cycle is determined mainly by the superposition of annual variations of T and O concentration. The winter peak for emission is determined exclusively by atomic oxygen concentration, whereas the summer peak is the superposition of all impacts.

In Troshichev et al. (2006) an error was made in the calculations of Polar Cap (PC) index scaling parameters. For the publication commented here, Troshichev et al. (2011), the authors state having used scaling parameters of the invalid PC index version but have actually substituted parameters from another version instead. The mingling of PC index versions has resulted in erroneous illustrations in Figs. 1, 2, 3, 6, 7, and 8 and the issuing of non-substantiated statements.

The commented publication by Janzhura and Troshichev (2011) constitute basis for IAGA endorsement by Resolution 3 (2013) of PC index calculations. However, there is strong disagreement between indications in the title, abstract, statements in the text, and figure captions, as well as in illustrations of results compared to re-calculations of the relations by rigorous use of the presented near-real time procedure. Against their statements, none of the illustrations present near-real time methods.