Collaborative Research: Lagrangian Simulations of the Madden Julian Oscillation over Warming Oceans

马登朱利安振荡（MJO）是一个在印度洋上空形成的大型天气系统，并缓慢向东移动，直到热带太平洋中部附近消散。 当它经过一个特定的位置时，它通常会导致持续15-30天的雨季，然后是干燥的天气，以及长时间的强烈西风。 伴随着MJO的环流在热带大气中一路环绕世界，它们影响着亚洲、澳大利亚和北美季风降雨的开始时间，以及热带风暴和飓风形成的时间和地点。 尽管它对全球天气和气候很重要，但几十年来，MJO在气候模型中的模拟效果很差，因此目前对它未来如何变化的预测是不可靠的。 参与该项目的科学家已经开发出一种新的天气模型，可以更好地预测MJO的行为。 它被称为“拉格朗日”，因为它不是在点的网格上求解大气运动方程，而是跟踪空气质量在世界各地的移动。拉格朗日天气模式将用于研究未来海洋变暖时MJO将如何变化，并更好地了解MJO的工作原理，因此它的代表性也可以在其他模式中得到改善。MJO未来变化的不确定性代表了气候变化的一个重要X因素。 初步结果表明，随着海洋变暖，MJO将加强，变得更加频繁，并影响更广泛的热带地区。 潜在的影响包括热带降雨模式的变化，热带风暴和飓风分布的改变，以及风模式的变化，这些变化有利于更频繁和持久的厄尔尼诺式海洋变暖。 该项目还将教育两名研究生和几名本科生关于模拟大气环流和气候动力学的技术。

The Madden Julian Oscillation (MJO) is a large weather system that forms over the Indian Ocean and moves slowly eastward until it dissipates near the middle of the tropical Pacific Ocean. When it passes a given location, it typically causes a rainy period that lasts 15-30 days that is followed by dry weather, as well as an extended period of strong westerly winds. The circulations that accompany the MJO go all the way around the world in the tropical atmosphere, and they affect when monsoon rainfall begins in Asia, Australia, and North America, as well as when and where tropical storms and hurricanes form. Despite its importance to global weather and climate, the MJO has been poorly simulated in climate models for decades, so current predictions of how it will change in the future are unreliable. The scientists involved in this project have developed a new kind of weather model that better predicts the behavior of the MJO. It is referred to as "Lagrangian," because instead of solving equations for atmospheric motions on a grid of points, it tracks air masses as they move around the world. The Lagrangian weather model will be used to study how the MJO will change in the future as the oceans warm, and to better understand how the MJO works, so its representation can be improved in other models as well.Uncertainty about future changes to the MJO represent an important X-factor for climate change. Preliminary results suggest that the MJO will intensify, become more frequent, and affect a broader region of the tropics as the oceans warm. Potential impacts include changes to tropical rainfall patterns, altered distributions of tropical storms and hurricanes, and changes in wind patterns that favor more frequent and persistent El Nino-like ocean warming. This project will also educate two graduate students and several undergraduate students about techniques in modeling atmospheric circulations and about climate dynamics.