Bubble Creation Rates From Breaking Wave Noise

海洋和大气之间的小范围转移过程是决定天气和气候的核心。在中到强风速期间，风力驱动的海洋波浪场携带大量气泡，这些气泡被认为对一些传输机制很重要，包括气泡介导的二氧化碳传输以及海洋气溶胶的产生和生物浓缩。尽管气泡调节过程很重要，但关于气泡产生速度的公开海洋数据很少，而且目前还没有可靠的方法在实地获得这些数据。这个项目探索了利用水下环境噪声通过破坏风浪来估计海-气界面上的气泡夹带率的想法。拟议实验的直接目标是将现有的为单沉降式实验室断路器开发的海浪噪声模型转换为风力驱动的溢流式断路器。主要问题是：1)现有的海浪噪声模型能准确地再现不同能量尺度上单个溢流破碎器产生的噪声吗？2)来自一组同时溢流破碎器的噪声能被再现吗？3)从破浪噪声推断出的气泡生成率能否与实验过程中对气泡生成率的独立估计相一致？这些问题将通过一系列关于风浪通道中溢出物破碎器的实验室研究来解决。在确定的研究体积内，将使用水听器阵列和摄像机监测单个泄漏破碎器的噪音，并将其与波浪和携带的气泡羽流的物理测量相关联。主要的羽流特征将是用光纤探头阵列测量的气泡尺寸分布。同时还将测量多个溢出式破碎器的噪声场。水槽混响将修正测量的海浪噪声，并将利用成功应用于早期波道测量的方法进行补偿。海浪噪声测量将与基于个别泄漏破碎器测量的物理特性的海浪噪声的模型计算进行比较。实验和数据分析将包括加州大学圣迭戈分校的本科生实习生和SIO夏季研究奖学金计划的参与。这些项目资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来管理初步实验。拟议的研究结果可能对中到强风速期间的海气交换过程产生广泛影响，特别是与二氧化碳的海气转移和海洋气溶胶产生有关的过程。这些过程归根结底与气候动态有关。

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.