Radioisotopic Measurements to Determine Plankton Nutrient Sources and Carbon Export at Station ALOHA

越来越多的生态学证据表明，北太平洋中部的海洋生态系统可能正在经历从氮限制初级生产的系统向磷限制初级生产的系统的转变。 在我们评估这种可能性及其海洋学和生态学意义之前，我们必须首先了解海洋水柱中磷循环的生物地球化学机制。 为此，该项目的主要研究员将利用自然产生的短寿命放射性核素磷-32、磷-33、钍-234和铍-7，对北太平洋环流的磷循环和颗粒有机碳输出进行研究。 P同位素测量将允许估计P在溶解池和颗粒池中的停留时间。 这项工作将与已经建立的美国每月JGOFS-HOT（夏威夷海洋时间序列）巡航计划一起进行。

ABSTRACTOCE-9906634There is mounting ecological evidence that the oceanic ecosystem of the central North Pacific Ocean my be undergoing a shift from a system in which nitrogen limits primary production to one limited by the availability of phosphorous. Before we can evaluate this possibility and its oceanographic and ecological significance, we must first understand the biogeochemical mechanisms working in the cycling of phosphorous in the oceanic water column. To that end, the principal investigator on this project will conduct a study of phosphorous cycling and particulate organic carbon (POC) export in the North Pacific gyre using the naturally-occurring, short-lived radionuclides Phosphorous-32, Phosphorous-33, Thorium-234, and Beryllium-7. The P isotope measurements would permit the estimation of P residence times in the dissolved and particulate pools. The work would be carried out in conjunction with an already established monthly U.S.JGOFS-HOT (Hawaiian Ocean Time Series) cruise program.