The Madden-Julian Oscillation in an Idealized General Circulation Model

摘要: Abstract The structure of the intraseasonal oscillations in tropics an idealized general circulation model with a zonally symmetric climate is described. Space-time spectra show peak zonal winds and velocity potential at equator wavenumbers 1 2, corresponding to eastward-propagating power phase speeds ≈18 m s−1. This speed significantly greater than that observed oscillation but comparable obtained similar models by Hayashi Sumi Swinbank et al. precipitation spectrum concentrated 2–5. A composite procedure used describe three-dimensional model's oscillation. characterized cells oriented along equatorial plane, enhanced region rising motion. Zonal wind changes tend be positively correlated geopotential height same level. Positive perturbations wat...