Collaborative Research: Dropsonde Measurements for Characterizing Lower Troposphere Moisture Variability and Air-sea Interaction over the Tropical Indian Ocean

合作研究：用于表征热带印度洋上空对流层低层湿度变化和海气相互作用的下投探空仪测量

• 批准号: 1062242
• 负责人: Shuyi Chen
• 金额: $ 24.78万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1062242&HistoricalAwards=false
• 关键词: Collaborative; Research; Dropsonde; Measurements; Characterizing

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 feedback Research under this award is conducted using dropsondes deployed from a NOAA WP-3D research aircraft, which will be based on the island of Diego Garcia. The dropsondes contain a full meterological instrument package and a GPS locator, and provide relatively high resolution measurements of atmospheric temperature, pressure, humidity, horizontal winds, and vertical velocity. The project also makes use of onboard aircraft measurements and data from airborne expendable bathythermographs (AXBTs) and airborne expendable conductivity-temperature-depth (AXCTD) probes, which can be launched from the aircraft along with the dropsondes. The aircraft also has substantial radar assets, and radar work is funded separately by NOAA, and additional funding for aircraft activities comes from the Office of Naval Research. The research considers the interaction between environmental moisture and convection (DYNAMO hypothesis 1) and the role of air-sea interaction (hypothesis 2) in the lifecycle of the MJO. The work on moisture-convection relationships is motivated by recent results showing that the outbreak of organized deep convection in the tropics resembles a non-equilibrium phase transition occurring at a temperature-dependent threshold value of column water vapor. But the moisture-convection relationship is complicated by the role of mid-tropospheric moisture and the fact that areas of shallow convection are prevalent following MJO initiation, as well as the drying effect of convective downdrafts. Work on air-sea interactions seeks to understand how air-sea interactions associated with the MJO in the Indian Oceand differ from their counterparts in the western equatorial Pacific observed during the TOGA-COARE field campaign in the 1990s. Air-sea interactions are expected to be different because large latent heat fluxes occur prior to convection in the Pacific Ocean (fig. 1 of the proposal), associated with MJO-related westerly wind bursts, while in the Indian Ocean the strongest winds (and presumably turbulent fluxes) occur during and after the convective phase of the MJO.Motivation for this project and more generally for DYNAMO comes from the many ways in which the MJO affects weather and climate worldwide. The MJO regulates the active and break periods of the Asian and Australian monsoon systems, serves as a forcing agent for El Nino events, and, when it propagates into the Pacific ocean, impacts weather over the United States. MJO activity over the Pacific Ocean has a strong influence on hurricane formation in the Gulf of Mexico. Improved prediction of the MJO could thus allow long-lead forecasts (up to two weeks) of its worldwide weather and climate impacts, and research conducted under this project could serve as the basis for such advances in MJO prediction. In addition, this project will provide support and training to a graduate student, thereby promoting the next generation of scientists in tropical meteorology and climate dynamics.

Madden-Julian振荡（Dynamo）现场运动的动力是2011年下旬/2012年印度洋的国际实验的美国，这是印度洋合作季节内变异性实验（CINDY2011）。 Dynamo的总体目标是加快对MJO在印度洋启动的过程的关键，并改善MJO的模拟和预测。现场运动将包括多个雷达，大气发声站点，一架研究飞机，多个研究船和海洋测量。发电机的三个主要假设是：1）只有当潮湿层在MJO尺度的一个区域内变得足够深时，才能将深对流组织成MJO对流的包膜；这种湿润发生的步伐决定了前发作状态的持续时间，2）在不同阶段进行的特定对流群体对于MJO的启动至关重要，3）屏障层，风和剪切驱动的混合，浅层热线，浅层热线，浅层热跃层，以及混合夹带在此中，所有在此中都在此中均在此供热中，在印度海洋范围内均在此中扮演并在印度海洋范围内发挥着重要的作用，并发挥着上层的含量，并在印度海洋的范围内发挥作用，并在SSOS海洋范围内供热。使用从NOAA WP-3D研究飞机部署的Dropsondes进行的，该飞机将基于迭戈·加西亚岛。 Dropsondes包含一个完整的计量仪器包和GPS定位器，并提供了相对较高的大气温度，压力，湿度，水平风和垂直速度的分辨率测量。 该项目还利用机载飞机测量和来自机载的消耗性沐浴仪（AXBT）和机载的可消耗性电导率 - 温度深度（AXCTD）探针的数据，这些探针可以与Dropsondes一起从飞机上启动。 飞机还具有大量的雷达资产，雷达工作由NOAA分别资助，飞机活动的额外资金来自海军研究办公室。该研究考虑了环境水分与对流之间的相互作用（Dynamo假设1）与MJO生命周期中气海相互作用（假设2）的作用（假设2）。 最近的结果表明，热带有组织的对流爆发类似于在柱水蒸气的温度依赖性阈值下发生的非平衡相变。 但是，水分转化关系使对流层中水分的作用以及MJO启动后普遍存在浅水区域以及对流下降气流的干燥作用的事实变得复杂。关于空气互动的工作旨在了解印度洋海洋中与MJO相关的空气互动与1990年代Toga-Coare Field竞选期间观察到的西赤道太平洋的同行不同。 预计气海相互作用会有所不同，因为在太平洋对流之前发生了大型潜热通量（提案的图1），与与MJO相关的西风爆发有关，而在印度洋，在印度洋，最有力的风（可能是湍流的磁通量（可能是动荡的磁通）在MJO的对流阶段和更为多样性的过程中，许多人都会出现多功能的方式。全球。 MJO规范亚洲和澳大利亚季风系统的积极和休息时间，是El Nino事件的强迫代理，当它传播到太平洋时，会影响美国的天气。太平洋上的MJO活动对墨西哥湾的飓风形成有很大影响。因此，改进对MJO的预测可以允许对其全球天气和气候影响的长期预测（长达两周），并且根据该项目进行的研究可以作为MJO预测的此类进步的基础。此外，该项目将为研究生提供支持和培训，从而促进热带气象和气候动态的下一代科学家。