Mathematical model describes planetary weather pattern

摘要

An anomalous weather pattern that occurs in 40- to 50-day cycles, the Madden-Julian Oscillation (MJO) enhances and suppresses tropical rainfall over a wide swath of the planet; it begins over the Indian Ocean and propagates eastward across the Pacific Ocean. Although the MJO affects monsoon development, intraseasonal weather in the midlatitudes, and the formation of El Nino, the oscillation's mechanism has not been well understood despite decades of research since its discovery in 1971. Andrew Majda and Samuel Stechmann developed a mathematical model that captures the fundamental physical features of this complex weather pattern. Whereas previous MJO models emphasized instability on the planetary scale, the authors suggest that the intraseasonal oscillation arises from stable climate interactions between equatorial moisture in the lower troposphere and synoptic scale atmospheric wave activity, which produces the system's dominant eastward propagation.