The Gulf Nutrient Stream

We present the historical development of the nutrient stream concept, from the initial ideas on the nutrient-bearing stratum and the transport of inorganic nutrients by the Gulf Stream to the large-scale inorganic and organic connections in the entire Atlantic Ocean. We mostly analyze and discuss available literature but also present some novel calculations using cruise data and the velocity fields from numerical re-analysis data. We first examine and discuss the structure of the Gulf Nutrient Stream, the significance of boundary exchange, and the importance of epipycnal and diapycnal processes. We then move to explore the subtropical and remote pathways into the Gulf Nutrient Stream, including the effect of the returning limb of the global overturning circulation, and end up reviewing the concept of nutrient irrigation of the subpolar gyre and its relevance in the spring-fall maintenance of the spring bloom. We close the chapter with some thoughts on the role of streams in the Earth system, as the key conduit for recycling properties within any ocean subsystem while simultaneously connecting the different subsystems, hence bringing about the complexity of the living planet.