Bubble Exchange in the Labrador Sea - 2023

这个项目的重点是了解海浪破碎形成的气泡是如何帮助海洋呼吸的。海洋和大气在海洋表面相连，大量的二氧化碳和氧气等气体不断地从两个方向穿过海洋表面。这是一个重要的过程，因为它有助于调节大气和海洋中碳和氧的数量；人类通过燃烧化石燃料向大气中排放的多余碳中，海洋吸收了大约25%。了解不同气体的呼吸过程对气候模型和了解这些气体对海洋生物的影响都很重要。当气体从大气转移到海洋时，它们可能在海洋表面附近保持溶解状态，或者在全球海洋的某些地方，它们可能被进一步向下输送，然后在许多世纪内不会回到表面。我们知道海上风暴加速了地表的海气交换，但我们还不能准确预测在最高风速下会交换多少气体。我们认为，在我们的理解中，关键的缺失环节是由波浪破碎形成的气泡，它有助于将气体推入海洋，尤其是在大风暴中。然而，我们并不确切地知道在最高的风中形成了多少气泡，一旦它们在水下，当气体被转移到海洋中时，它们会去哪里。我们还怀疑，风和海浪的复杂性，以及海洋表面附近复杂的水流模式，可能对结果有很大影响。这个项目的目的是在大风暴期间测量海洋顶部几米的气泡过程，以了解气泡如何促进气体交换。在这个项目中，我们将在北大西洋的一艘德国科考船上参加国际合作。我们的同事将测量气体交换、气象学和发生在海洋顶部几百米的过程。我们将测量气泡，溶解气体浓度和海洋顶部八米的流动模式。定制的气泡相机、气体传感器和测量水流的声学设备将安装在一个长桅杆浮标上，该浮标可以在大风暴中自行漂浮数天。这将使我们能够跟踪气泡是如何移动的，当它们向海洋释放气体时，以及这些气体是如何在海洋表面附近移动的。这些数据将用于理解气泡介导的气体交换机制，并将用于测试和开发由我们的同事建立的计算模型。这个项目的优势在于，在合作者之间，我们可以同时观察不同规模和时间尺度的所有关键过程，因此我们将能够了解它们如何相互影响。结果将是更好地理解气泡的重要性，这样我们就可以改进我们对所有气体的气体转移的预测。

The focus of this project is to understand how bubbles formed by breaking waves at sea can help the ocean breathe. The ocean and atmosphere are connected at the ocean surface, and huge quantities of gases like carbon dioxide and oxygen continuously cross that surface in both directions. This is an important process because it helps regulate the amount of carbon and oxygen in both atmosphere and ocean; the ocean has taken up around 25% of the excess carbon that humans have added to the atmosphere by burning fossil fuels. Understanding this breathing process for different gases is important for climate models and also to understand the influence of these gases on ocean life.When gases are transferred from the atmosphere to the ocean, they may remain dissolved near the ocean surface, or in some parts of the global ocean they may be transported further downwards and then won't return to the surface for many centuries. We know that storms at sea speed up the air-sea gas exchange across the surface, but we are not yet able to predict exactly how much gas will be exchanged at the highest wind speeds. We think that the critical missing link in our understanding is the bubbles formed by breaking waves, which help to push gas into the ocean, especially in big storms. However, we don't know exactly how many bubbles are formed in the highest winds, where they go once they're underwater and when the gas is transferred to the ocean. We also suspect that the complexities of wind and waves, and complicated water flow patterns near the ocean surface may have a strong influence on the outcome. The aim of this project is to measure the bubble processes in the top few metres of the ocean during large storms in order to understand how bubbles contribute to gas exchange.During this project, we will join an international collaboration on a German research ship in the North Atlantic. Our colleagues will be measuring gas exchange, meteorology and the processes occurring in the top few hundred metres of the ocean. We will measure the bubbles, the dissolved gas concentrations and the flow patterns in the top eight metres of the ocean. Custom-built bubble cameras, gas sensors and acoustic devices to measure water flow will be mounted on a long spar buoy which can float by itself for several days in large storms. This will enable us to follow how the bubbles move, when they give up their gas to the ocean, and how that gas moves around near the ocean surface. This data will be used to understand the mechanisms of bubble-mediated gas exchange, and will be used to test and develop computational models built by our colleagues. The advantage of this project is that between the collaborators, we can watch all the critical processes at different size and time scales simultaneously, so we will be able to learn how they influence each other. The outcome will be better understanding of why bubbles matter, so that we can improve our predictions of gas transfer for all gases.