Equatorial Waves, Diurnal Tides and Small‐Scale Thermal Variability in the Tropical Lower Stratosphere From COSMIC‐2 Radio Occultation

A new constellation of radio occultation satellites called COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere, and Climate-2) is providing unprecedented dense measurements the tropical atmosphere, with on average more than 4,000 high quality observations per day over 40°N–S. We use these data to evaluate large- small-scale thermal variability in lower stratosphere during October 2019 – April 2020. Space-time spectral analysis 6-hourly gridded reveals a rich spectrum traveling planetary-scale waves, including Kelvin mixed Rossby-gravity waves inertia gravity addition propagating diurnal tides. These coherent modes show enhanced amplitudes from tropopause through (∼17–25 km). Characteristics temperature variances, calculated as deviations fields, reveal systematic spatial patterns time maxima Africa South America overlying frequent deep convection. Small-scale variances also exhibit transient equatorial tied local variations static stability, associated large-scale waves. The provide novel details near above tropopause.