CAREER: Development of a broadband acoustic system for quantifying the flux of free gas in methane seeps

职业：开发宽带声学系统，用于量化甲烷渗漏中游离气体的通量

• 批准号: 1352301
• 负责人: Thomas Weber
• 金额: $ 69.08万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1352301&HistoricalAwards=false
• 关键词: CAREER; Development; broadband; acoustic; system

In this CAREER proposal the PI requests funding to develop a broadband acoustic system to quantify the depth dependent bubble size distribution and gas void fraction in methane seeps, and to measure the flux of methane gas escaping the seabed and rising through the water column. Inversion of acoustic measurements for these quantities will exploit the mechanical resonance of bubbles by observing the bubbles response at a wide range of frequencies (1-100 kHz). The acoustic system will employ a constant beamwidth transducer for much of its frequency range (10-100 kHz) in order to accurately treat bubble plumes with different size distributions that are in close spatial proximity, as is sometimes observed to happen. The system will be designed to integrate into a deepwater remotely operated vehicle (ROV) and to function at full ocean depth. A second operational mode will be established where the system can be towed from a ship of opportunity as part of a more rapid, wide-scale acoustic survey strategy. The development and use of a wideband acoustic system can directly address hypotheses about the fate and evolution of methane gas bubbles escaping the seabed. The use of the proposed system has the potential to provide transformative results including 1) refined estimates of the global flux of methane escaping the seabed, 2) increased understanding of the oceans capacity as a methane sink, and 3) estimates of the global flux of methane reaching the atmosphere from seabed seeps.Broacer ImpactsThe data provided by the proposed instrument could be of considerable benefit to the wider scientific community. Methane seeps are thought to affect ocean chemistry, ocean microbial life and atmospheric chemistry, with consequences for ocean productivity, radiation balance in the atmosphere and paleoclimate studies. Basic information on these seeps is lacking, and the proposed instrument could make a significant contribution to plugging this hole in our understanding. Several undergraduate and graduate students would benefit from the experience of helping with the development and testing of a novel device. The idea of having undergraduates do the development work for the schools echo-sounder kit is excellent. The outreach component would reach the pupils at several local schools, and has the written support of both local teachers and the New Hampshire Sea Grant. The collaborations with industry, Sea Grant, and other agencies provides evidence that the project will have a wide spread and lasting impact and that it is perceived by many other scientists as an important problem and a good approach to the problem.

在这项职业建议中，PI要求资金开发宽带声学系统，以量化甲烷渗漏中的深度依赖性气泡尺寸分布和气体空隙分数，并测量甲烷气体的通量，从而逃脱了海床并通过水柱上升。这些数量的声学测量值的反转将通过观察到广泛频率（1-100 kHz）的气泡响应来利用气泡的机械共振。声学系统将在其大部分频率范围（10-100 kHz）中采用恒定的梁宽传感器，以便准确处理具有不同尺寸分布的气泡羽流，这些分布在空间上是紧密的，有时会观察到发生。该系统的设计旨在集成到深水远程操作的车辆（ROV）中，并在全海深度运行。将建立第二种操作模式，其中可以从机会船上拖走该系统，这是一种更快，大规模的声学调查策略的一部分。 宽带声系统的开发和使用可以直接解决有关逃避海床的命运和进化的假设。 The use of the proposed system has the potential to provide transformative results including 1) refined estimates of the global flux of methane escaping the seabed, 2) increased understanding of the oceans capacity as a methane sink, and 3) estimates of the global flux of methane reaching the atmosphere from seabed seeps.Broacer ImpactsThe data provided by the proposed instrument could be of considerable benefit to the wider scientific community.甲烷渗漏被认为会影响海洋化学，海洋微生物生命和大气化学，对海洋生产率，大气中的辐射平衡和古气候研究产生了影响。缺乏有关这些渗漏的基本信息，拟议的仪器可以为在我们的理解中填补这一漏洞做出重大贡献。几位本科生和研究生将从帮助开发和测试新颖设备的经验中受益。让本科生为学校回声的套件进行开发工作的想法非常好。外展部分将在几所当地学校到达学生，并得到当地教师和新罕布什尔州海补助金的书面支持。与行业，SEA Grant和其他机构的合作提供了证据，表明该项目将产生广泛的影响和持久的影响，并且许多其他科学家将其视为一个重要的问题，并且是解决该问题的良好方法。