Processes Influencing Carbon Cycling: Observations of the Lower limb of the Antarctic Overturning (PICCOLO)

环绕着南极洲大陆的辽阔而遥远的海洋统称为南大洋。这一地区有着多山的海洋、冬季的黑暗、强风、冰冻的温度和冰的恶劣环境，不出所料，它是全球海洋中勘探最少、观测不足的部分之一。然而，由于这些极端情况，它在地球气候系统中扮演着巨大的、仍然无法量化的角色。在这个地区，大量的热量和二氧化碳在大气和海洋之间交换。控制这些大气-海洋交换的物理机制是NERC管弦乐队计划的主题。我们建议在短笛舞曲中专注于化学和生物在这些交流中所起的作用。特别是，Piccolo将重点了解海水中所含碳在上升到南极洲附近的表面时，在下降到海洋深处之前与近表面的大气、冰、浮游植物和浮游动物相互作用的机制。Piccolo将对南极洲附近的地区进行海洋研究考察，因为计算机模型和卫星图像显示，这些地区是碳过程的关键地区。这些地区冻结的海水会将盐分释放到下面的水中，使水更稠密，从而导致海水下沉。强风导致海冰被推离南极海岸线，留下了被称为波尼亚的开阔水域。在波利尼亚，夏季的水有足够的光线让浮游植物生长，还提供了沉入深海的稠密水，驱动着一个巨大的海洋传送带，这对地球的气候系统产生了很大的影响。Piccolo团队将测量控制该地区生物和化学过程的关键变量，包括铁、营养物质、浮游植物和浮游动物。至关重要的是，该团队将研究这一生物和化学系统不同部分之间的控制速率条件。Piccolo团队将利用包括自动潜水器、滑翔机和浮标在内的最新技术，在海冰下等原本无法进入和以前未被研究的区域观察这些过程。最雄心勃勃的是，我们将把一艘潜艇锚定在波尼亚号内的海床上，让它在冬季收集数据，第二年春天再找回它。Piccolo团队将在海豹身上放置仪器，海豹在水中上下潜水时将不断采集数据，并通过卫星通信链路实时发送给科学家。这些丰富的新数据将由Piccolo团队使用最先进的计算机模型进行分析，以测试我们关于整个复杂的物理、化学和生物过程如何影响碳的想法。从概念上讲，我们将通过这个系统追踪一个想象中的水团，观察大气和海洋之间的过程，表层的生物过程，上层和下层海洋之间的交换，以及碳的最终命运。短笛假说涉及下列问题：(1)控制海洋与大气之间二氧化碳交换的因素以及紫外线在控制海水中二氧化碳浓度方面的作用；(2)光、铁和营养物质在水中浮游生物处理碳的过程中的作用；(3)控制碳从上层海洋向深海输出的中介过程；(4)使碳进入下一阶段全球旅行深海的过程。

The vast, remote seas which surround the continent of Antarctica are collectively known as the Southern Ocean. This region with its severe environment of mountainous seas, winter darkness, strong winds, freezing temperatures and ice is unsurprisingly one of the least explored and under-observed parts of the global ocean. However, because of these extremes, it plays a large and still unquantified role in Earth's climate system. In this region, large amounts of heat and carbon dioxide are exchanged between the atmosphere and the ocean. The physical mechanisms controlling these atmosphere-ocean exchanges are the subject of the NERC ORCHESTRA programme. We propose within PICCOLO to concentrate on the role that chemistry and biology play within those exchanges. In particular, PICCOLO will focus on understanding the mechanisms that transform the carbon contained in the seawater as it rises to the surface near Antarctica, interacts with the atmosphere, ice, phytoplankton and zooplankton inhabiting the near surface, before descending to the ocean depths. PICCOLO will undertake an ocean research expedition to the region close to Antarctica, as computer models and satellite images show that these are areas crucial for carbon processes. Freezing seawater in these regions releases salt into the water below, making it denser and therefore causing it to sink. Strong winds cause the sea ice to be pushed away from the Antarctic coastline, leaving areas of open water called polynyas. Within the polynyas the water has enough light during the summer to allow phytoplankton to grow, as well as providing dense waters which sink to the deep, driving a giant ocean conveyor belt which has a large impact upon Earth's climate system. The PICCOLO team will measure the key variables that control the biological and chemical processes in this region including iron, nutrients, phytoplankton and zooplankton. Crucially the team will study the controlling rate terms between different parts of this biological and chemical system. The PICCOLO team will make use of the latest technologies, including autonomous submarines, gliders and floats, to observe these processes in otherwise inaccessible and previously unstudied areas such as under the sea ice. Most ambitiously we will anchor a submarine to the seabed within a polynya and leave it over a winter season to collect data, recovering it the following spring. The PICCOLO team will put instruments on seals which will continuously take data as they dive up and down through the water, sending it back to scientists in real-time via satellite communication links. This wealth of novel data will be analysed by the PICCOLO team, using state of the art computer models, to test our ideas about how the whole complex set of physical, chemical and biological processes affects carbon. Conceptually we will follow an imaginary parcel of water through the system looking at processes between the atmosphere and ocean, biological processes in the surface layer, exchanges between the upper and lower ocean and the final fate of the carbon. The PICCOLO hypotheses address the following: (i) Factors controlling the exchange of carbon dioxide between the ocean and atmosphere and the role of ultra-violet light in controlling the concentration of carbon dioxide in seawater;(ii) The role of light, iron and nutrients in how carbon is processed by the plankton in the water; (iii) The mediating processes governing the export of carbon from the upper ocean to depth;(iv) The processes that take the carbon into the deep ocean on the next stage of its global journey.