Collaborative Research: Dynamics of the MJO (DYNAMO) Scientific Program Overview

合作研究：MJO (DYNAMO) 动力学科学计划概述

• 批准号: 1021702
• 负责人: Steven Rutledge
• 金额: $ 1.53万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1021702&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; MJO; DYNAMO

This is an award to support continued planning for DYNAMO. It is not a commitment by NSF to fund the field project and related analysis and numerical simulation work. Those funding decisions will be determined by means of further review.The Dynamics of the Madden-Julian Oscillation (DYNAMO) project is a field campaign to study the iniitiation of the Madden-Julian Oscillation (MJO), followed by a suite of data analysis, modeling, and forecasting studies. The MJO is an envelope of organized convection that propagates from the Indian Ocean to the Pacific Ocean and constitutes the dominant form of intraseasonal precipitation and atmospheric circulation variability in the tropics. The MJO influences a variety of tropical weather and climate phenomena,including tropical cyclones (affecting hurricanes in the Gulf of Mexico), the onset and intraseasonal fluctuations of the monsoons and rainfall over Asia, Australia, Africa, and the Americas, and the onset of El Nino events. Despite its importance and concerted efforts over several decades, the MJO has not yet been adequately explained, and global atmospheric circulation models have difficulty simulating and predicting it.The field campaign is planned for October 2011 to March 2012, to take advantage of an international effort known as the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011). The DYNAMO observing array would take the form of a quadrangle observing array consisting of two ships and two islands. The islands are Diego Garcia (approximately 7S, 72E) and Gan, the southernmost island of the Maldive chain (near 0S, 73E). The ships would be located roughly 10 degrees east of the islands, and one ship station would held by a US research vessel (RV) while the other would be held alternately by RVs from Japan, Australia, and India. The RVs collect atmospheric and oceanographic observations using a combination of moored buoys, ship-based air-sea flux measurements, radars, and radiosonde launches. A radar "supersite" including radars of varying wavelengths, is planned for Gan, in addition to radiosonde launches on the island. Diego Garcia provides radiosonde launches to allow a four point observing array which can be used to compute the convergence of atmospheric heat and moisture fluxes.The DYNAMO project seeks to test three general hypotheses regarding the initiation of the MJO, which focus on the interaction between convection and environmental moisture, the evolution of cloud populations, and air-sea interaction. The first hypothesis is that "Deep convection can be organized into an MJO convective envelope only when the moist layer has become sufficiently deep over a region of the MJO scale, and the pace at which this moistening occurs determines the duration of the pre-onset state. The second hypothesis is that specific convective cloud populations at different stages are essential to MJO initiation. Clouds are considered to play two roles, one as a moistening agent through detrainment and the other as a driver of large-scale circulation through diabatic heating. The third hypothesis is that air-sea interactions and ocean conditions play an essential role in the initiation of the MJO, particularly in establishing the tropical Indian Ocean as the locus of MJO onset.The project aims to improve the ability of numerical models to provide forecasts of MJO activity, which would be of great societal benefit due to the connections between the MJO and fluctuations of weather and climate (including hurricanes). DYNAMO would also have a strong educational benefit by introducing young scientists, including graduate students, to the tropical meteorology and oceanogaphy of the Indian Ocean. A field campaign on the scale of DYNAMO has not previously been carried out in the Indian Ocean, and the data collected during the campaign would be beneficial for a variety of purposes, including improvements to convective parameterization in climate models and the calibration and validation of satellite retrievals.

该奖项旨在支持 DYNAMO 的持续规划。 NSF 并不承诺资助该实地项目以及相关的分析和数值模拟工作。这些资助决定将通过进一步审查来确定。马登-朱利安振荡动力学 (DYNAMO) 项目是一项实地活动，旨在研究马登-朱利安振荡 (MJO) 的启动，然后进行一系列数据分析，建模和预测研究。 MJO 是有组织对流的包络线，从印度洋传播到太平洋，构成热带季节内降水和大气环流变化的主要形式。 MJO 影响多种热带天气和气候现象，包括热带气旋（影响墨西哥湾的飓风）、亚洲、澳大利亚、非洲和美洲季风和降雨的爆发和季节内波动，以及热带气旋的爆发。厄尔尼诺事件。尽管它很重要并且经过了几十年的共同努力，但 MJO 尚未得到充分解释，全球大气环流模型也难以对其进行模拟和预测。现场活动计划于 2011 年 10 月至 2012 年 3 月进行，以利用国际努力被称为 2011 年印度洋季节内变率合作实验（CINDY2011）。 DYNAMO观测阵列将采用四边形观测阵列的形式，由两艘船和两个岛屿组成。这些岛屿是迪戈加西亚岛（大约南纬 72 度）和马尔代夫群岛最南端的甘岛（南纬 73 度附近）。这些船只将位于岛屿以东约 10 度处，其中一个船站将由一艘美国研究船 (RV) 驻守，而另一个船站将由来自日本、澳大利亚和印度的 RV 轮流驻守。 RV 利用系泊浮标、船基海空通量测量、雷达和无线电探空仪发射的组合来收集大气和海洋观测数据。除了在岛上发射无线电探空仪外，还计划在甘岛建造一个包括不同波长雷达的雷达“超级站点”。迪戈加西亚岛提供无线电探空仪发射，以允许四点观测阵列，该阵列可用于计算大气热量和湿度通量的收敛。DYNAMO 项目旨在测试有关 MJO 启动的三个一般假设，该假设侧重于对流之间的相互作用和环境湿度、云群的演变以及海气相互作用。第一个假设是“只有当潮湿层在 MJO 尺度区域变得足够深时，深层对流才能组织成 MJO 对流包络，并且这种湿润发生的速度决定了预发生状态的持续时间第二个假设是，不同阶段的特定对流云群对于 MJO 的启动至关重要，云被认为发挥着两种作用，一是通过脱轨作为润湿剂，二是作为大规模环流的驱动力。第三个假设是，海气相互作用和海洋条件在 MJO 的启动中发挥着至关重要的作用，特别是在建立热带印度洋作为 MJO 启动的场所方面。该项目旨在提高数值模型的能力。提供 MJO 活动的预报，由于 MJO 与天气和气候波动（包括飓风）之间的联系，这将具有巨大的社会效益。通过向包括研究生在内的年轻科学家介绍印度洋的热带气象学和海洋学，DYNAMO 还将带来巨大的教育效益。 DYNAMO规模的实地活动以前从未在印度洋进行过，活动期间收集的数据将有利于多种目的，包括改进气候模型中的对流参数化以及卫星的校准和验证检索。