Bubble Creation Rates From Breaking Wave Noise

破碎波噪声产生气泡的速度

• 批准号: 1061050
• 负责人: Grant Deane
• 金额: $ 63.14万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1061050&HistoricalAwards=false
• 关键词: Bubble; Creation; Rates; Breaking; Wave

Small-scale transfer processes between the ocean and atmosphere are central to determining weather and climate. During moderate to strong wind speeds the wind-driven ocean wave field entrains large numbers of bubbles thought to be important for a number of transfer mechanisms, including bubble-mediated CO2 transport and the production and biological enrichment of marine aerosols. Despite the importance of bubble-mediated processes very little open ocean data exists on bubble creation rates and the present time there is no reliable method for obtaining these data in the field. This project explores the idea of using the underwater ambient noise to estimate bubble entrainment rates at the air-sea interface by breaking wind waves. The immediate goal of the proposed experiments is to transition an existing wave noise model developed for single plunging laboratory breakers to wind-driven spilling breakers. The primary questions are: 1) Can the existing wave noise model accurately reproduce the noise from individual spilling breakers over a variety of energetic scales? 2) Can the noise from an ensemble of simultaneous spilling breakers be reproduced? 3) Can bubble creation rates, inferred from breaking wave noise, be reconciled with independent estimates of bubble creation rates made during the course of the experiment?These questions will be addressed with a series of laboratory studies with spilling breakers in a wind-wave channel. The noise of individual spilling breakers within a defined study volume will be monitored with hydrophone arrays and video cameras, and correlated with physical measurements of the wave and entrained bubble plumes. The primary plume characterization will be bubble size distributions measured with an array of fiber optic probes. Measurements will also be made of the noise field from simultaneous multiple spilling breakers. Tank reverberation will modify the measured wave noise and will be compensated for using a method successfully applied to earlier wave channel measurements. Wave noise measurements will be compared with model calculations of wave noise based on the measured physical properties of individual spilling breakers.Broader Impact. The experiment and data analysis will include the participation of undergraduate interns from UCSD and the SIO summer research fellowship program. These programs sponsor students from around the country to gain hands-on experience in oceanography. A post-doctoral scholar will be employed to manage the primary experiment. The results of the proposed research are likely have broad impact in the field of air-sea exchange processes during moderate to strong wind speeds, particularly those associated with air sea gas transfer of CO2 and marine aerosol production. These processes are ultimately tied to climate dynamics.

海洋和大气之间的小规模转移过程是决定天气和气候的核心。在中到强风速度期间，风力驱动的海浪场夹带大量气泡，这些气泡被认为对一些传输机制很重要，包括气泡介导的CO2传输以及海洋气溶胶的产生和生物富集。尽管气泡介导的过程非常重要，但关于气泡生成率的公海数据很少，目前还没有可靠的方法在实地获得这些数据。 本计画探讨利用水下环境杂讯，以破开风浪来估测海-气界面气泡卷吸率。拟议的实验的直接目标是过渡到现有的波噪声模型开发的单一暴跌实验室破碎机风驱动溢出破碎机。主要问题是：1）现有的波浪噪声模型能否准确地再现各种能量尺度上的单个溢出破碎机的噪声？2)从一个同时溢出的破碎机合奏噪音可以复制？3)从破碎波噪音推断出的气泡产生率能否与实验过程中对气泡产生率的独立估计相一致？这些问题将通过一系列的实验室研究来解决，在风浪通道中使用溢出式破碎机。将用水听器阵列和摄像机监测规定研究体积内的单个溢出破碎机的噪声，并将其与波浪和夹带气泡羽流的物理测量结果相关联。主要的羽流特性将是用光纤探针阵列测量的气泡尺寸分布。还将对同时多个溢流破碎机产生的噪声场进行测量。坦克混响将修改测量的波噪声，并将使用一种成功地应用于早期波通道测量的方法进行补偿。波浪噪声测量值将与基于单个溢流破碎机的测量物理特性的波浪噪声模型计算值进行比较。实验和数据分析将包括来自UCSD和SIO夏季研究奖学金计划的本科实习生的参与。这些项目赞助来自全国各地的学生获得海洋学方面的实践经验。将聘请一名博士后学者管理初步实验。拟议研究的结果可能会在中等至强风速度下的海气交换过程领域产生广泛影响，特别是与二氧化碳的海气转移和海洋气溶胶产生有关的海气交换过程。这些过程最终与气候动态有关。