Atmospheric gravity waves play highly important roles in the dynamic and chemical processes in the upper atmosphere. To assess their magnitude, continuous full diurnal cycle measurements of temperature perturbations are necessary. In this paper we have calculated the large-scale gravity wave modulations between 85 and 99 km altitude based on the measurements by a unique Na lidar at Utah State University in the month of September from 2011 to 2015. The waves with period of 3–5 h dominate.

Results from a high-altitude balloon experiment conducted from a low-latitude station in India are presented in this work. The objectives of this experiment were to probe and understand the processes driving the various electric field sources at low latitudes. During this experiment, electric fields in the range of 5–6 mV m⁻¹ were observed at the balloon float altitude of 35 km. Atmospheric waves of few 100 km horizontal wavelength are suggested to be a potential source of these electric fields.

This is the first statistical study of the motion of patchy pulsating aurora (PPA). Our results show that PPA patches mainly drift eastward after midnight and westward before midnight, which suggests that the drifts of auroral patches could be a proxy for the ionospheric convection and provide a convenient and accurate method to remotely sense the magnetospheric convection. We also found that patch velocities do not seem to depend on AE index.

A near-infrared imaging spectrograph (NIRIS) has been developed in-house and is being operated from a low-latitude location, Gurushikhar, Mount Abu (24.6° N, 72.8° E), in India. The results presented in this study provide us with a comprehensive picture of mesospheric wave dynamics in terms of characterizing their response to various sources (solar and atmospheric) that give rise to the variability in the mesospheric intensities and temperatures.

In the present paper diffuse auroral intensities of OI λ1356 Å emission have been calculated, resulting from pitch angle diffusion of magnetospheric electrons by whistler-mode waves. Three cases are considered for estimating precipitation flux into the atmospheric loss cone. An analytical yield spectrum (AYS) approach is used to calculate energy deposition of electrons in the atmosphere of Ganymede. It is found that the intensities are inadequate to account for the observational intensities.

The determination of the polytropic index the plasma sheet of Earth's magnetosphere using THEMIS data. The data set reveals that the active magnetotail density and pressure data are well correlated. Yet, considering broad distributions of specific entropies, the evaluation is best performed on shorter timescales.

Although the number of terrestrial GNSS receivers is rapidly growing, the rather unevenly distributed observations do not allow the generation of high-resolution global ionosphere products. With the regionally enormous increase in GNSS data, the demands on near real-time products are growing very fast. Thus, a procedure for estimating the vertical total electron content based on B-spline representations and Kalman filtering was developed and validated by self-consistency check and altimetry.

A study of trends in the middle stratosphere using comparisons of four main reanalyses (ERA-Interim, JRA-55, MERRA and NCEP/NCAR). We identified that all four reanalyses show very similar trends on a season or monthly basis. We also compute trends for each grid point not as a zonal mean. This approach shows detailed features in the trend studies in both hemispheres.

We find double-layer structure events with percentages of 10.32 and 7.25 % compared to total PMCs events, and the mean distances between two peaks are 3.06 and 2.73 km for the NH and SH respectively using SOFIE data from 2007 to 2014. By analysis of the background temperature and water vapour residual profiles, we conclude that the lower layer is a reproduced one formed at the bottom of the upper layer. These structures have close relationships with temperature enhancements and GWs.

We propose a new GPS tomographic parameterization approach based on inverse distance weighted (IDW) interpolation. This approach can reconstruct a humidity field. In the future, the fusion of GNSS and external measurements from other sensors in the GPS tomography system will be a potential means to enhance the stability and reliability of water vapor tomography and to decrease tomography intervals.

In situ spacecraft data in space plasma are obtained often as time series data. Using Taylor's frozen-in flow hypothesis, one can interpret the time series data as spatial variations swept by the slow and passing by the spacecraft. A quantitative method for estimating the error for Taylor's hypothesis is developed here.

Measurements of equatorial thermospheric winds obtained from an optical instrument called a Fabry–Perot interferometer in Ethiopia show a significance difference as compared with other longitudinal sectors. The zonal wind in this sector is small and shows a gradual decrease through out the night. Application of climatological wind and temperature models shows good agreement with the observations over Ethiopia.