Collaborative Research: GEOTRACES Arctic Section: The Geochemistry Size-fractionated Suspended Particles Collected by in-situ Filtration

参加2015年美国GEOTRACES北极考察的伍兹霍尔海洋研究所的一名研究人员将收集和分析北冰洋西部的悬浮颗粒物，以更好地了解该地区微量元素的循环。与国际GEOTRACES计划中的其他多国倡议一样，美国北极考察的目标是确定控制海洋中关键微量元素和同位素分布的过程和量化通量，并确定这些分布对环境条件变化的敏感性。一些微量元素是生命所必需的，另一些是已知的生物毒素，还有一些是重要的，因为它们可以用作海洋中各种物理，化学和生物过程的示踪剂。颗粒是GEOTRACES程序的一个关键参数，因为它们作为源、汇和微量元素循环的作用。这项研究的结果将通过与阿拉斯加土著群体的联系分享。该项目将涉及培训研究生和本科生。北冰洋的粒子循环与其他海洋盆地有着深刻的不同。北极中部常年被冰雪覆盖，初级生产力极低，导致生物泵非常薄弱。几乎没有粒子通量来自上面，粒子到北极盆地的主要来源似乎是从边缘的横向运输，这些横向运输的粒子有更高的成岩含量比通常发现在其他海洋盆地的粒子。北极地区颗粒的不同来源和组成可能会为从水柱中去除颗粒反应性微量元素及其同位素建立一个完全不同的动态，而不是目前所了解的。对北极地区悬浮颗粒的浓度和组成尚未进行全面调查。 在这项研究中，大小分级的悬浮颗粒将进行分析的主要阶段和微量元素的组成，测量需要确定清除去除颗粒反应元素，并提供深入了解控制生物泵的机制。

An investigator from Woods Hole Oceanographic Institution participating in the 2015 U.S. GEOTRACES Arctic expedition will collect and analyze suspended particulate matter in the Western Arctic Ocean to better understand cycling of trace elements in the region. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. Particles are a key parameter for the GEOTRACES program because of their role as sources, sinks, and in the cycling of trace elements. Results from this study will be shared through outreach to native groups in Alaska. The project will involve training of graduate and undergraduate students.Particle cycling in the Arctic Ocean is profoundly different from other ocean basins. Extremely low primary production in the perennially ice-covered central Arctic leads to a very weak biological pump. With little particle flux coming from above, the dominant source of particles to the Arctic Basin appears to be lateral transport from the margins, and these laterally transported particles have much higher lithogenic content than is typically found in particles in other ocean basins. The different source and composition of particles in the Arctic potentially sets up a completely different dynamic for the removal of particle-reactive trace elements and their isotopes from the water column than is currently understood. There has yet to be a comprehensive survey of the concentration and composition of suspended particles in the Arctic. In this study, the size-fractionated suspended particles will be analyzed for major phases and trace element composition, measurements needed to determine scavenging removal of particle reactive elements and provide insight into the mechanisms controlling the biological pump.