Atmospheric Sounding Network in the Dynamics of the Madden-Julian Oscillation Project (DYNAMO)

马登-朱利安涛动（DYNAMO）场运动的动力学是2011年底/ 2012年初在印度洋进行的一项国际实验——印度洋季节内变率合作实验（CINDY2011）的美国组成部分。DYNAMO的总体目标是加快对印度洋MJO形成的关键过程的理解，并改进对MJO的模拟和预测。实地考察活动将包括多部雷达、大气探测站点、一架研究飞机、多艘研究船和海洋测量。DYNAMO的三个主要假设是：1)只有当湿层在MJO尺度上足够深时，深层对流才能组织成MJO对流包络；2)不同阶段的特定对流种群对MJO的形成至关重要；3)阻挡层、风切变混合、浅层温跃层和混合层夹带通过控制上层海洋热含量和海温对印度洋MJO的形成起重要作用。本合同用于DYNAMO探空网络的规划和实施，以及后续的质量控制和分析。DYNAMO测深网络将由四个地点组成：Gan、Diego Garcia和两艘研究船。研究人员将为DYNAMO规划测深网络，并建立测深数据监测系统，该系统将用于数据的现场质量控制和快速产品的制备。活动结束后，该团队将为DYNAMO建模社区准备大规模强迫场，并进行诊断研究，包括辐散和绝热加热剖面以及MJO整个生命周期的边界层演变。这些任务将有助于解决DYNAMO活动的假设1和2。除了主要的DYNAMO假设之外，研究人员还确定了他们计划测试的另外两个假设：1)印度洋MJO开始前（变湿或预调节）阶段，并不是对流层下层水汽逐渐稳定积累的阶段，而是水汽场逐步演变的阶段，这与不同云群的发展有关；(2)印度洋中部混合层深度及其性质在MJO时间尺度上发生变化，这些变化与DYNAMO观测到的云和降水场的演变有对应关系。该研究的更广泛影响包括多个研究生参与实地活动和数据分析。一个成功的DYNAMO活动将提高对热带对流、MJO的可预测性以及MJO对美国和其他地区天气的下游影响的认识。

The Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign is the US component of an international experiment in late 2011/early 2012 in the Indian Ocean, the Cooperative Indian Ocean Experiment on Intraseasonal Variability (CINDY2011). The overarching goal of DYNAMO is to expedite understanding of processes key to MJO initiation over the Indian Ocean and to improve simulation and prediction of the MJO. The field campaign will include multiple radars, atmospheric sounding sites, a research aircraft, multiple research vessels, and oceanic measurements. The three main hypotheses of DYNAMO are: 1) 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; the pace at which this moistening occurs determines the duration of the pre-onset state, 2) Specific convective populations at different stages are essential to MJO initiation, and 3) The barrier layer, wind- and shear-driven mixing, shallow thermocline, and mixing-layer entrainment all play essential roles in MJO initiation in the Indian Ocean by controlling the upper-ocean heat content and SST, and thereby surface flux feedbackThis award is for planning and implementation of the sounding network for DYNAMO, as well as follow up quality control and analysis. The DYNAMO sounding network will consist of four locations: Gan, Diego Garcia, and two research vessels. The researchers will plan the sounding network for DYNAMO and establish a sounding data monitoring system which will be used for field quality control of the data and preparation of quick-look products. After the campaign, the team will prepare large-scale forcing fields for the DYNAMO modeling community, as well as conduct diagnostic studies involving the divergence and diabatic heating profiles and the boundary layer evolution through the life cycle of the MJO. These tasks will help to address Hypotheses 1 and 2 of the DYNAMO campaign. In addition to the overarching DYNAMO hypotheses, the researchers have identified two others that they plan to test: 1) The pre-onset (moistening or pre-conditioning) phase of the MJO over the Indian Ocean, rather than exhibiting a gradual, steady build-up of moisture in the lower troposphere, is characterized by a stepwise evolution of the moisture field, which is related to the development of distinct cloud populations, and 2) The mixed-layer depth and its properties over the central Indian Ocean vary on the timescale of the MJO and these variations have corresponding relationships to the evolving cloud and precipitation fields observed during DYNAMO.The broader impacts of the research include the involvement of multiple graduate students in the field campaign and data analysis. A successful DYNAMO campaign would lead to improved understanding of tropical convection, the predictability of the MJO, and downstream effects of the MJO on weather in the United States and other areas.