Based on the gradient balance wind theory and the SABER observations, a dataset of monthly mean zonal wind has been developed at heights of 18–100 km and latitudes of 50° Sndash;50° N from 2002 to 2019. The dataset agrees with the zonal wind from models (MERRA2, UARP, HWM14) and observations by meteor radar and lidar at seven stations. The dataset can be used to study seasonal and interannual variations and can serve as a background for wave studies of tides and planetary waves.

The Na layer in the upper atmosphere is very sensitive to solar radiation and varies considerably during sunrise and sunset. In this paper, we use the lidar observations and an advanced model to investigate this process. We found that the variation is mostly due to the changes in several photochemical reactions involving Na compounds, especially NaHCO₃. We also reveal that the Fe layer in the same region changes more quickly than the Na layer due to a faster reaction rate of FeOH to sunlight.

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.