Glider observations of productivity in the Alboran Sea (GOPITAS)

海洋植物贡献了全球净初级产量的大约一半，从而维持渔业和世界粮食供应。目前由人为温室气体排放引起的气候变化可能会通过改变温度、海洋环流、pH、营养物质和光的可获得性来影响这种生产。因此，了解是什么推动了生产是海洋科学的一个关键问题。在这里，我们建议进行一项试点研究，涉及UEA的三架海洋滑翔机，通过观察推动地中海西部阿尔伯兰海生产的物理、化学和生物过程，为改善这种理解做出重大贡献。在温带和极地海洋，冬季翻转为表层生产提供营养，但在副热带涡旋中，这一机制太弱，无法克服营养限制。阿尔博兰海的涡旋行为类似于副热带涡旋，但要小得多，因此更容易研究。在这些区域，较小尺度的过程可能起到重要作用，例如，中尺度(10-100公里)和次中尺度(1-10公里)的风/湍流相互作用。通过传统的船上调查来解决这些小规模的过程成本高昂，在技术上也具有挑战性。最近开发的自主平台和传感器可以显著增强传统的舰载工作。例如，一支由3000个ARGO浮标组成的船队现在定期采集世界海洋上层2公里的温度和盐度分布(www.argo.ucsd.edu)，帮助我们更好地了解海洋热量收支和环流。生物和化学传感器为这些技术增添了更多的维度。特别是，氧气传感器可以测量群落的净生产量，即产氧光合作用和耗氧呼吸之间的平衡。因此，在全球范围内连续测量关键参数和进程成为可能。浮子只能在水柱中垂直漂浮，否则就会被动漂浮。滑翔机的开发在一定程度上克服了浮标的有限操纵性。这些自主飞行器可以在垂直方向和水平方向上进行交互导航，并在空间和时间上获得高分辨率的海洋物理和生物地球化学参数的深度剖面。他们可以看到卫星无法穿透海面的地方，一次工作几个月，而且比传统的海洋巡航便宜得多。我们建议使用三架滑翔机同时测量阿尔博兰海的物理、化学和生物参数。阿尔博兰海是地中海西部的一个小型季节性少营养环流系统，毗邻两个锋区。我们的总体目标是确定如何最好地利用滑翔机来提高我们对所有时间和空间尺度上维持生物生产的过程的理解。GOPITAS的试点研究将把一种生物地球化学成分带到由北约海底研究中心(NURC)组织的REP10奥波兰海国际实验中，涉及多达15架滑翔机。这笔小额赠款足以支持GOPITAS，这要归功于我们项目合作伙伴的慷慨实物支持，包括免费使用HMS Roebuck(英国海军)和NRV Alliance(北约)舰艇，以及滑翔机制造商(IRobot)的部署和技术支持。这将是全球同时部署三架生物地球化学滑翔机的首批项目之一。

Marine plants contribute about half of the global net primary production and thus sustain fisheries and world food supplies. Current climate change caused by anthropogenic greenhouse gas emissions is likely to affect this production through changes in temperature, ocean circulation, pH, nutrient and light availability. Understanding what drives production is therefore a key problem of marine science. Here, we propose a pilot study involving UEA's three ocean gliders, to make a significant contribution to improving this understanding by observing the physical, chemical and biological processes driving production in the Alboran Sea, western Mediterranean. In the temperate and polar oceans, winter overturning provides nutrients for surface production, but in the subtropical gyres this mechanism is too weak to overcome nutrient limitation. The gyres of the Alboran Sea behave like the subtropical gyres, but are much smaller and therefore easier to study. In such regions, smaller-scale processes are likely to contribute significantly, e.g., wind/turbulence interactions at the mesoscale (10-100 km) and submesoscale (1-10 km). Resolving these small-scale processes through traditional ship-board surveys is expensive and technically challenging. Recently developed autonomous platforms and sensors can significantly enhance traditional ship-based work. For example, a fleet of >3000 Argo floats now take regular temperature and salinity profiles of the upper 2 km of the world's oceans (www.argo.ucsd.edu) and help improve our understanding of oceanic heat budgets and circulation. Biological and chemical sensors add further dimensions to these technologies. In particular, oxygen sensors can measure net community production, i.e. the balance between oxygen-producing photosynthesis and oxygen-consuming respiration. Continuous measurements of key parameters and processes have thus become possible on a global scale. Floats can only vertically in the water column and are otherwise drifting passively. Gliders have been developed to partly overcome the limited manoeuvrability of floats. These autonomous vehicles can be interactively piloted in the vertical as well as horizontal direction and acquire depth profiles of marine physical and biogeochemical parameters with high resolution in space and time. They can 'see' where satellites cannot penetrate the surface, work for months at a time and are much cheaper than traditional oceanographic cruises. We propose the use of three gliders for simultaneous measurements of physical, chemical and biological parameters in the Alboran Sea, a small seasonally oligotrophic gyre system in the western Mediterranean Sea, adjacent to two frontal zones. Our overall goal is to establish how to best use gliders to improve our understanding of processes sustaining biological production, on all temporal and spatial scales. The GOPITAS pilot study will bring a biogeochemical component to the international REP10 Alboran Sea experiment organised by the NATO Undersea Research Centre (NURC) involving up to 15 gliders. The Small Grant is sufficient to enable GOPITAS thanks to the generous support in kind from our project partners, including free access to the ships HMS Roebuck (UK Navy) and NRV Alliance (NATO) as well as deployment and technical support from the glider manufacturer (iRobot). This will be one of the first deployments worldwide of three biogeochemical gliders simultaneously.