Sub-Tropical Gyre Study: Anthropogenic Carbon and Biological Degradation in the Twilight Zone (Forschungsantrag M 60/5)

拟议的北大西洋副热带环流水柱多学科调查是沿着上世纪80年代初S在海洋-北大西洋调查中的美国瞬变示踪器(TTO-NAS)期间最后一次占据的区段进行的。连同2003年的亚极地环流巡航(M.Rhein教授)，我们的邮轮为国际(德国、美国、英国)重新占领TO-NAS站提供了核心贡献。一个主要目标是使用无机碳和化学示踪剂数据来检查北大西洋22年间人为碳(Cant)的增加情况。这是凯勒Sonderforschungsbereich 460的Teilprojekt A5的目标。这些数据将使用多变量时间序列分析技术以及示踪剂-Cant相关性进行评估，以量化人为碳增加。巡航的第二个目标是检查中大洋水柱内生物成因物质的再矿化，因为大多数成分是从真光层底部到大约1.000米深之间的深度层中的颗粒中释放出来的。为审查再矿化过程，计划对中层带的中上层群落进行详细分析，并进行实验以评估颗粒崩解率。由于固氮被认为对这些水域的营养物质化学计量比有很大的影响，因此对重氮菌的固氮和生物多样性的研究也是这些调查的一部分。这样的研究还将允许检验有争议的建议(Pahlow和Riebesell，2001)，即北大西洋的营养-氧气化学计量比一直在改变。

The proposed multidisciplinary investigation of the water column of the North Atlantic subtropical gyre is oriented along sections last occupied during the US Transient Tracers in the Ocean - North Atlantic Survey (TTO-NAS) of the early 1980's. Together with a sub-polar gyre cruise in 2003 (Prof. M. Rhein), our cruise provides a central contribution to an international (Germany, USA, UK) reoccupation of TTO-NAS stations. A major goal is to use inorganic carbon and chemical tracer data to examine the increase of anthropogenic carbon (Cant) in the North Atlantic over a time interval of 22 years. This is the goal of Teilprojekt A5 of the Kieler Sonderforschungsbereich 460. The data will be assessed using multivariate time-series analysis techniques as well as tracer-Cant correlations in order to quantify the anthropogenic carbon increase. A second goal of the cruise is the examination of remineralization of biogenic materials within the mesopelagic water column, since most constituents are being released from particles in the depth horizon between the base of the euphotic zone and ca. 1.000 m depth. Detailed analysis of the pelagic community in the mesopelagic zone and experiments to asses rates of particle breakdown are planned to examine the remineralization processes. Since nitrogen fixation is assumed to have a substantial influence on nutrient stoichiometric ratios in these waters dephts, studies of nitrogen fixation and biodiversity of diazotrophs are also part of these investigations. Such studies will also allow for examination of the controversial suggestion (Pahlow and Riebesell, 2001) that the nutrient-oxygen stoichiometry of the North Atlantic has been changing.