2022/12/06- 分享人:魏云涛
发布时间: 2022-12-05



个人简介

魏云涛,青年副研究员。主要研究方向为次季节-季节(S2S)尺度诊断、模拟和预报;日变化,天气尺度(例如对流耦合赤道波动,热带气旋),S2S,季节,和年际尺度(例如ENSOIODQBO)等之间的多尺度相互作用;复杂地形和海陆分布(如海洋性大陆区域)对天气和气候变率的影响;热带-热带外相互作用。


报告摘要

The Madden-Julian Oscillation (MJO) intensity and propagation undergo significant year-to-year variations, behind which the leading mode of the tropical 2-7-year variability (e.g., El Niño-Southern Oscillation, ENSO) plays an important role. Despite many studies focused on the impacts of the diversified ENSO warm phases on MJO, no one has ever tried to understand the possible MJO variations in different types of ENSO cold phases (i.e., La Niña). Here, we find that MJO tends to be broader, stronger and faster when a La Niña has its cooling center over the eastern Pacific. However, when the La Niña cooling peaks over the central Pacific, the atmosphere ahead of MJO becomes drier and more stabilized, and thus the MJO eastward propagation is constrained, slower and weaker. The remote influences of MJO over North America (East Asia) are likely stronger when the La Niña cooling center shifts eastward (westward). These results help us construct a whole paradigm of ENSO diversity influencing MJO and also support the necessity to consider the two types of La Niña when exploring different ENSO impacts on global weather and climate.