Case analysis of diurnal stratospheric Rayleigh temperature and atmospheric fluctuations based on 589 nm lidar

Observational analysis of the Earth’s stratospheric temperature structure and its dynamical behavior is of great significance for atmospheric dynamics research. In this paper, we present stratospheric temperatures in the range of 30–50 km above the Yinchuan observation site, retrieved from diurnal continuous Rayleigh scattering signal observation data collected by a 589 nm lidar throughout a single day. We also present observational studies of atmospheric tides and gravity wave cases. The diurnal temperature background field and perturbation field were obtained from the lidar data using the linear fitting method; these results exhibit good consistency with the temperature perturbation field extracted from ERA5. An obvious quasi-monochromatic inertial gravity wave was detected by application of a two-dimensional Fourier transform to the nighttime observation data with complete height coverage, which revealed these characteristic gravity wave parameters: a vertical wavelength of 8.53 km, a period of 8.46 h, and a downward-propagating vertical phase velocity. A nonlinear least-squares harmonic fitting method was used to extract amplitudes and phases of atmospheric diurnal and semi-diurnal tides in the 30−34 km range, where the diurnal data were relatively complete. The amplitudes increased with height, ranging from 0.6 to 2.5 K (diurnal tide) and 0.3 to 1.9 K (semi-diurnal tide), respectively. The phases showed a decreasing trend with height, indicating that the vertical phase velocity of the tides propagates downward while the energy propagates upward. These results indicate that diurnal 589 nm lidar observations data can provide important reference values for understanding the temperature structure of the stratosphere and the dynamical characteristics of atmospheric gravity waves and tides.