Collaborative Research: The Cariaco Basin Oceanographic Time Series Program

这项合同将提供资金，使1995年11月开始在北纬10°30‘，西经°40’的卡里亚科盆地继续经营海洋时间序列五年。Cariaco(有色海洋碳保持)是美国国家科学基金会(NSF)支持的三个海洋生物地球化学时间序列站之一。该时间序列旨在通过继续收集一组精心挑选的生物、化学、地质和物理测量数据，达到了解影响沉入加勒比盆地底部的颗粒物通量的海洋过程的科学目标。这项工作的一个主要目标是通过在加勒比盆地维持一个观测设施，为海洋碳和生物地球化学以及古气候研究界提供服务。该设施能够研究季节、年际和年代际时间尺度上的时间变异性和趋势，提供一套核心观察和样本与社区共享，并便利进入这一独特的海洋环境。Cariaco是由NSF(马萨诸塞大学达特茅斯分校、斯通布鲁克大学和哥伦比亚南卡罗林大学)与委内瑞拉自然科学基金会和国际热带生态中心合作的三个美国机构的科学家联合开展的研究工作。Cariaco盆地是位于加勒比海东南部委内瑞拉大陆边缘的一个1400米深的洼地，在浅(约140米)的海床上公开与热带大西洋表面相连。由于周转缓慢，下沉物质的分解导致250米以下的缺氧。这些条件保存了良好的沉积记录，被国际社会用来研究全新世和晚更新世的气候变化。了解影响下沉物质的过程是理解将物质从表层海洋转移到海底的“生物碳泵”，以及理解海洋在过去、现在和未来气候中的作用的关键。在这方面，Cariaco有助于解释保存在该沉积物记录中的气候历史。Cariaco计划还试图教育公众了解这种关系。智力价值：该科学计划遵循以下假设：(1)颗粒物的下沉通量包含上层海洋状况从事件到年际尺度的变化记录，包括上升流、通风、生产力和陆源输入事件。(2)养分有效性的变化导致了生态系统的变化，这些变化保存在化学和沉降物的数量上。(3)盆地水文地貌的时间变化与区域风变率、加勒比海涡旋在海床附近的通过以及大西洋环流的变化直接相关。(4)缺氧-缺氧过渡带附近的细菌产生和碳分解受中深层溶解氧的侧向输送(通风事件)控制。(5)缺氧-缺氧过渡带附近的化学自养细菌改变了垂直颗粒物通量和溶解有机质浓度的组成和数量。CARIACO生成的观测数据用于评估侧向输送和上升流的变异性、水柱化学、浮游植物、浮游动物和细菌群落组成的强迫和变化、初级生产力和细菌生产的变化(化学自养和异养)，以及由此导致的水柱化学和下沉到海底的颗粒物通量的组成和数量的变化。该项目使用密集的传统海洋学和气象技术，以及包括卫星和分子观测在内的现代工具。广泛影响：Cariaco解决了美国政府海洋研究优先计划和实施战略以及美国气候变化科学计划战略计划中确定的一些最优先事项。这种不间断的、长期的热带记录对于研究气候变化和大尺度海洋生物地球化学之间的关系很有价值。许多科学家认为，热带在各种时间尺度的盆地范围的过程中发挥着关键作用，包括那些与社会相关的过程。Cariaco的测量还将有助于了解影响区域渔业和灾难性天气模式的过程。Cariaco制定了开放共享数据、样本和基础设施的政策，以便利第三方在Cariaco盆地进行更广泛的研究或过程研究。该项目汇集了物理、化学、地质和生物海洋学家的国际劳动力。它具有技术转让和人力资源开发的影响，为拉丁美洲的科学家、技术人员和学生提供了参与物流规划、实地考察、数据分析和联合出版物的机会，以解决与当地和全球相关的问题。这些交流也对包括少数族裔在内的美国学生产生了重要的教育影响。委内瑞拉政府认为Cariaco是他们最重要的海洋研究项目之一，并将继续向当地参与者提供大量资金。

This award will provide funds to continue operating the oceanographic time series started in November 1995, in the Cariaco Basin at 10º 30'N, 64º 40'W, for five years. CARIACO (CArbon Retention In A Colored Ocean) is one of three ocean biogeochemistry time series stations supported by the National Science Foundation (NSF). The time series addresses the scientific objective of understanding ocean processes that affect the flux of particles sinking to the bottom of the Cariaco Basin, by continuing collection of a carefully-selected set of biological, chemical, geological and physical measurements. A key objective of this effort is to serve the Ocean Carbon and Biogeochemistry (OCB) and the paleoclimate research communities by maintaining an observing facility in the Cariaco Basin. The facility permits studies of the temporal variability and trends that span seasonal, interannual and interdecadal time scales, provides a set of core observations and samples to share with the community, and facilitates access to this unique oceanographic setting. CARIACO is a joint research effort by scientists at three U.S. institutions supported by NSF (University of Massachusetts at Dartmouth, Stony Brook University, and the University of South Carolin at Columbia) in partnership with the Fundacion LaSalle de Sciencias Naturales and the Centro Internacional de Ecologia Tropical in Venezuela.The Cariaco Basin is a 1,400-m deep depression located on the Venezuelan continental margin in the southeastern Caribbean Sea, openly connected to the surface tropical Atlantic Ocean above a shallow (~140 m) sill. Because of slow turnover, decomposition of sinking material leads to anoxia below about 250 m. These conditions preserve an excellent sediment record that is used by the international community to study Holocene and late Pleistocene changes in climate. Understanding processes that affect the sinking material is the key to understanding the "biological carbon pump" that transfers materials from the surface ocean to the bottom, and to understanding the ocean?s role in past, present, and future climate. In this regard, CARIACO aids in the interpretation of the climate history preserved in this sediment record. The CARIACO program also seeks to educate the public about this relationship.Intellectual merit: The scientific program is guided by the following hypotheses: (1) The sinking flux of particulate matter contains a record of event- to interannual-scale changes in upper ocean conditions, including upwelling, ventilation, productivity, and terrigenous input events. (2) Changes in nutrient availability results in ecosystem shifts that are preserved in the chemistry and amount of sinking particles. (3) Temporal changes in the hydrography of the basin are directly related to regional wind variability, the passage of Caribbean Sea eddies near the sill, and circulation changes in the Atlantic Ocean. (4) Bacterial production and carbon decomposition near the oxic-anoxic transition zone are controlled by lateral transport of dissolved oxygen at mid-depth (ventilation events). (5) Chemoautotrophic bacteria near the oxic-anoxic transition zone alter the composition and amount of the vertical particulate flux and the dissolved organic matter concentration.CARIACO generates observations used to assess variability in lateral transport and upwelling, forcing and variations in water column chemistry, phytoplankton, zooplankton and bacteria community composition, variations in primary productivity and bacterial production (chemoautotrophic and heterotrophic), and resulting changes in water column chemistry and the composition and quantity of particulate flux sinking to the bottom. This program uses intensive traditional oceanographic and meteorological techniques, as well as modern tools including satellite and molecular observations.Broader impacts: CARIACO addresses some of the highest priorities identified in the U.S. government's Ocean Research Priorities Plan and Implementation Strategy and the Strategic Plan for the U.S. Climate Change Science Program. The uninterrupted, long-term tropical record is of value to investigations of the relationship between climate change and large-scale ocean biogeochemistry. Many scientists believe the tropics play a pivotal role in these basin-wide processes on a variety of time scales including those relevant to society. CARIACO measurements will also help understand processes that affect regional fisheries and catastrophic weather patterns. CARIACO has established a policy of open sharing of data, samples, and infrastructure, to facilitate the conduct of broader studies or of process studies in the Cariaco Basin by third parties. This project brings together an international workforce of physical, chemical, geological and biological oceanographers. It has technology transfer and human resource development impacts, providing an opportunity for scientists, technicians and students from Latin America to participate in logistics planning, fieldwork, data analysis, and joint publications that address issues of local and global relevance. These exchanges also have an important educational impact on U.S. students including minorities. The Venezuelan government considers CARIACO among their most important oceanographic research programs, and will continue significant funding to local participants.