Ocean Gateways and Choke Points: Progress and Challenges

全球海洋环流以无数种方式影响着我们的气候，并在调节地球对气候变化的反应中发挥着核心作用。这种循环的一个关键方面是特定的局部通道（或阻塞点）的重要性，它们控制着循环的强度、结构和盆地连通性。这种入口的例子是印度尼西亚的通流，阿古拉斯反射，以及罗斯海和威德尔海的流出。这些系统通常由多个在空间和时间尺度范围内变化的强喷流组成，因此观察、建模和预测仍然极具挑战性。阿诺德·戈登教授横跨50多年的独特研究生涯，改变了我们对海洋门户及其在气候、生物地球化学和生态系统中的作用的理解。鉴于新的观测技术的快速发展，以及一类新的高分辨率全球海洋模型的出现，这些模型对于理解气候变化的加速速度至关重要，评估海洋门户领域的知识状况并确定未来研究的关键挑战的时机已经成熟。这个为期两天的研讨会将汇集来自世界各地的杰出和早期职业研究人员，包括观察学家，理论家和建模者，以解决这些问题。该研讨会将于2020年2月在圣地亚哥的斯克里普斯海洋学研究所举行，恰逢阿诺德·戈登80岁生日，并在2020年海洋科学会议前一周举行，以尽量减少在旅行上花费的时间和金钱。该基金将支持15名早期职业研究人员的参与，他们将接触到海洋门户领域的机遇和挑战。除了出席专题讨论会的人员外，还将利用广泛的网络外展活动，确保有广泛、多样化的与会者。研究结果将通过EOS上的一篇文章进行分享，并纳入各国和国际科学议程。像阿尔戈这样的当代全球海洋观测项目并没有对海洋门户进行足够的空间和时间细节采样，以揭示它们的物理特性。监测这些门户需要专门的观测活动和持续的系泊观测站。关于这些通道在气候时间尺度上的路径、结构和变异性的许多基本问题仍未得到解答。至关重要的是，从过去获得的关于如何成功收集这些观测资料的知识应传递给下一代海洋学家，以保持早期研究的动力并推进新的观测技术。传统上，数值模型很难真实地代表海洋门户，但计算能力和数值技术的进步最近导致了重大改进。将观测界和建模界聚集在一个研讨会上将促进快速进展，并为确定系统中的知识差距提供一个独特的论坛，以便为未来的门户观测系统建立更好的综合战略。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The global ocean circulation affects our climate in myriad ways and plays a central role in mediating the planet's response to climate change. A key aspect of this circulation is the importance of specific localized gateways (or choke points) which control the strength, structure and basin connectivity of the circulation. Examples of such gateways are the Indonesian Throughflow, the Agulhas retroflection, and outflows from the Ross and Weddell Seas to name a few. These systems often consist of multiple strong jets that vary over a range of space and time scales and so remain extremely challenging to observe, model and predict. Professor Arnold Gordon's singular research career, spanning over 50 years, has transformed our understanding of ocean gateways and their role in climate, biogeochemistry and ecosystems. Given the rapid development of new observing technologies, and the emergence of a new class of high-resolution global ocean models that are critical for understanding the accelerating rate of climate change, the time is ripe to assess the state of knowledge in the field of ocean gateways and define key challenges for future research. This two-day workshop to bring together distinguished and early-career researchers from across the world, including observationalists, theoreticians and modellers to address these topics. The workshop, to be held at Scripps Institution of Oceanography in San Diego in February 2020, will coincide with Arnold Gordon's 80th birthday and occur in the week prior to the 2020 Ocean Science meeting to minimize time and money spent on travel. This grant will support the participation of 15 early career researchers, who will gain exposure to the opportunities and challenges in the field of ocean gateways. Extensive web-based outreach will be used to ensure a broad, diverse pool of participants in addition to those present at the symposium. Results will be shared via an article in EOS and incorporated in the various national and international science agendas. Contemporary global ocean observing programs like Argo do not sample ocean gateways with sufficient spatial and temporal detail to uncover their physics. Monitoring these gateways requires specialized, dedicated observational campaigns and sustained moored observatories. Many fundamental questions about the pathways, structure and variability of these gateways on climate time scales remain unanswered. It is crucial that the knowledge garnered from the past of how to successfully collect these observations is passed on to the next generation of oceanographers, to maintain the impetus from earlier studies and to advance new observing technology. Numerical models have traditionally struggled to realistically represent ocean gateways, but advances in computational power and numerical techniques have recently led to major improvements. Bringing together the observational and modeling communities at a single workshop will catalyze rapid progress and provide a unique forum for identifying knowledge gaps in the system so as to build a better integrated strategy for a gateway observing system of the future.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.