Physics and Recycling Efficiency as Factors Controlling New (Nitrate) Production in the Southern Ocean

该项目是美国联合全球海洋通量研究（U.S. jgofs）南大洋过程研究的一部分，旨在(1)更好地了解南大洋有机和无机碳通量，(2)确定调节这些通量的大小和变化的物理、生态和生物地球化学因素和过程，以及(3)将这些通量置于当代全球碳循环的背景下。作为美国jgofs的第四个研究区域，南大洋可能是这个跨学科项目研究的最重要的区域。南大洋的巨大面积和丰富的营养物质引起了人们对它在过去和现在与大气的碳交换中所起的作用的广泛猜测，以及这种作用如何响应未来的气候扰动而变化。因此，该项目将测量硝酸盐的吸收以及地表水中铵、区域和溶解氨基酸来源的氮的吸收和再生。将测量硝酸盐吸收的光响应，并分析大小分布，以确定垂直混合如何影响当地的新产量。虽然该项目将对南大洋的所有主要地理区域进行采样，但重点将放在研究区域北部的锋面系统以及南部的永久无冰区域。这个广阔的区域包含了世界海洋中最大的、不间断的生物地球化学省。因此，这项工作解决了JGOFS的目标，即确定调节生物生产的幅度和可变性及其从地表水的最终输出的因素，这将对打算预测南大洋对气候变化的反应的未来模式的成功至关重要。

9530981 Sambrotto This project is part of the U.S. Joint Global Ocean Flux Study (U.S.JGOFS) Southern Ocean Process Study aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological, and biogeochemical factors and processes regulating the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. As the fourth U.S.JGOFS study region, the Southern Ocean in potentially the most significant yet examined by this interdisciplinary program. The Southern Ocean's vast size together with its abundance of nutrients has led to extensive speculation about its role in past and present-day exchanges of carbon with the atmosphere as well as how this role may change in response to future climactic perturbation. Thus project will measure nitrate uptake and the uptake and regeneration of nitrogen from ammonium, area, and dissolved amino acid sources in surface water. The light response of nitrate uptake will be measured and the size distribution analyzed to determine how vertical mixing can affect the local rates of new production. Although all of the major physiographic regions of the Southern Ocean will be sampled during this project, the focus will be on the frontal systems at the northern portion of the study area as well as the permanently ice- free region immediately to the south. This extensive region encompasses the largest, uninterrupted biogeochemical province in the world ocean. Thus, the work addresses the JGOFS goal of identifying the factors that regulate the magnitude and variability of biological production and its ultimate export from surface water and will be critical to the success of future models that intend to predict the response of the Southern Ocean to climate change.