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: 1023539
• 负责人: Robert Houze
• 金额: $ 0.75万
• 依托单位: University of Washington
• 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=1023539&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.

这是一个奖项，以支持继续规划的CNOO。美国国家科学基金会并不承诺为现场项目及相关分析和数值模拟工作提供资金。这些资助决定将通过进一步审查的方式来确定。马登-朱利安振荡（MJO）项目的动力学是一项研究马登-朱利安振荡（MJO）初始化的实地活动，随后是一套数据分析，建模和预测研究。MJO是从印度洋传播到太平洋的有组织对流的包络，构成了热带地区季节内降水和大气环流变率的主要形式。MJO影响各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开始和季节内波动，以及厄尔尼诺事件的开始。尽管它的重要性和几十年来的共同努力，MJO尚未得到充分的解释，全球大气环流模型很难模拟和预测它。实地活动计划于2011年10月至2012年3月进行，以利用被称为2011年印度洋季节内变率合作实验（CINDY 2011）的国际努力。该观测阵列将采用由两艘船和两个岛屿组成的四边形观测阵列的形式。这些岛屿是迭戈·加西亚（约7S，72 E）和甘，马尔代夫链最南端的岛屿（近0 S，73 E）。这些船将位于岛屿以东约10度，一个船站将由美国研究船（RV）控制，另一个将由日本，澳大利亚和印度的RV交替控制。考察船综合使用系泊浮标、船基海气通量测量、雷达和无线电探空仪，收集大气和海洋观测资料。除了在岛上发射无线电探空仪外，还计划在甘岛建立一个包括不同波长雷达的雷达“超级站点”。迭戈·加西亚提供无线电探空仪发射，以允许一个四点观测阵列，可用于计算大气热和水分通量的收敛。MJO项目旨在测试关于MJO启动的三个一般假设，重点是对流和环境水分之间的相互作用，云群的演变，以及海气相互作用。第一个假设是“只有当湿润层在MJO尺度的区域上变得足够深时，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爆发前状态的持续时间。第二个假设是，特定的对流云人口在不同的阶段是必不可少的MJO启动。云被认为起着两种作用，一种是通过疏散作为增湿剂，另一种是通过非绝热加热作为大尺度环流的驱动力。第三个假设是，海气相互作用和海洋条件发挥了至关重要的作用，在启动的MJO，特别是在建立热带印度洋作为MJO发作的轨迹，该项目旨在提高数值模式的能力，提供MJO活动的预测，这将是巨大的社会效益，由于MJO和天气和气候（包括飓风）的波动之间的联系。印度洋热带气象学和海洋学组织还将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而产生巨大的教育效益。以前从未在印度洋开展过1000万人规模的实地活动，活动期间收集的数据将有益于各种目的，包括改进气候模型中的对流参数化以及卫星检索的校准和验证。