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

这是一个奖励，以支持继续规划DYNAMO。NSF不承诺资助实地项目和相关的分析和数值模拟工作。这些供资决定将通过进一步审查确定。麦登-朱利安振荡动力学（DYNAMO）项目是一项研究麦登-朱利安振荡（MJO）起源的实地活动，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层，构成了热带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、非洲和美洲的季风和降雨的开始和季节内波动，以及厄尔尼诺现象的开始。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，全球大气环流模式难以模拟和预测它。实地活动计划于2011年10月至2012年3月进行，以利用名为“2011年印度洋季节内变化合作实验”（CINDY2011）的国际努力。发电机观测阵列将采取由两艘船和两个岛组成的四边形观测阵列的形式。这些岛屿是迪戈加西亚岛（约7S， 72E）和甘岛，马尔代夫群岛最南端的岛屿（近0S， 73E）。考察船将位于岛屿以东约10度的地方，其中一个考察站将由一艘美国考察船（RV）控制，而另一个考察船将由来自日本、澳大利亚和印度的RV轮流控制。rv利用系泊浮标、船载海气通量测量、雷达和发射无线电探空仪的组合收集大气和海洋学观测数据。除了在岛上发射无线电探空仪外，还计划在该岛建立一个包括不同波长雷达的雷达“超级基地”。迪戈加西亚提供无线电探空发射，允许一个四点观测阵列，可用于计算大气热量和水分通量的收敛。DYNAMO项目旨在测试关于MJO起源的三个一般假设，这些假设侧重于对流和环境湿度之间的相互作用，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尺度的一个区域上变得足够深时，深层对流才能组织成MJO对流包络，而这种湿润发生的速度决定了开始前状态的持续时间。”第二种假设是，不同阶段的特定对流云群对MJO的形成至关重要。云被认为扮演两个角色，一个是通过降水作为润湿剂，另一个是通过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在MJO的开始中起着重要作用，特别是在将热带印度洋确定为MJO开始的地点方面。该项目的目的是提高数值模式提供MJO活动预报的能力，由于MJO与天气和气候（包括飓风）波动之间的联系，这将带来巨大的社会效益。DYNAMO还将通过向年轻科学家，包括研究生介绍印度洋的热带气象学和海洋学，具有很强的教育效益。以前还没有在印度洋开展过DYNAMO规模的实地活动，在活动期间收集的数据将有助于各种目的，包括改进气候模式中的对流参数化以及对卫星检索的校准和验证。

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.