Short- and long-term stationary planetary wave variability in the middle atmosphere in contemporaneous satellite and reanalysis data

Abstract

Short- and long-term variabilities of stationary planetary waves (SPW) in the middle atmosphere are investigated from temperatures obtained from two satellites (Formosa Satellite-3/Constellation Observing System for Meteorology, Ionosphere and Climate (FORMOSAT-3/COSMIC) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED)) and a reanalysis dataset (ERA-Interim). COSMIC data analysis with a smaller window size enables investigation of short-term variabilities and wavelet analysis shows the presence of 30 to 120 days oscillations in the stratosphere during different years and are attributed to wave-mean flow interactions. This result in observational data is seen only due to the use of COSMIC data and its unique sampling pattern that enabled the extraction of short-term variability. Additionally, annual and quasi-biennial features are also observed. SABER analysis also shows similar long-term variations. The annual variation in both datasets shows linearly increasing spectral power indicating that the stratosphere is increasingly becoming chaotic and irregular and the dynamics are becoming stronger and expanding equatorward. Vertically upward propagation of SPW1 and SPW2 into the mesosphere is hindered during Sudden Stratospheric Warmings (SSW) due to the prevalent westward winds and smaller mesospheric amplitudes are observed. During no SSW years, larger SPW1 and SPW2 amplitudes are seen in the mesosphere. A positive correlation is observed between COSMIC SPW amplitudes and gravity wave (GW) potential energy (Ep) while the longitudes of maximum amplitudes are out of phase.