Time Series Particle Flux Measurements in the Sargasso Sea

鉴于人们对温室气体增加对全球气候的人为扰动的担忧，了解海洋在年际和年代际时间尺度上的变异性引起了广泛的兴趣和越来越大的相关性。可以肯定的是，海洋生态系统将受到气候模式变化的影响，迫切需要评估海洋对可能的气候变化情景的反应并对其进行建模。这需要从根本上了解海洋及其生物群如何对气候和环境强迫变量做出自然反应。海洋观测是必要的第一步。长期研究对我们了解海洋是如何工作的贡献是多方面和深远的。然而，这样的研究非常罕见--特别是那些专注于生物地球化学的研究。自1978年以来，海洋通量计划(OFP)一直在测量马尾藻海深处的颗粒通量。28年的OFP时间序列是迄今为止同类时间序列中最长的，其对深海的关注也是独一无二的。OFP在“生物泵”中制作了一份独特的、尽管经过“编辑”的时间变异性记录，这里大致指的是从表面向深海的物质转移。OFP为深海的季节性以及深海通量和上层海洋过程之间的紧密耦合提供了第一个直接证据。它提供了明确的证据，表明中上层水域对通量的生物再处理和对悬浮物质的清除的强度。该记录记录了由中尺度变率和气象强迫之间的相互作用所驱动的深层通量和短期波动的年际和更长时间的变化。时间序列变得足够长，可以开始研究多年盆地尺度气候强迫的可变性，例如北大西洋涛动。在这一奖项的资助下，百慕大生物研究站和海洋生物实验室的研究人员将继续运行这一独特的基本海洋学时间序列。随着记录的变长，我们能够更好地从气候和海洋功能之间的相互作用的角度来看待所观察到的波动。百慕大的三个共同协调和互补的时间序列--OFP、百慕大大西洋时间序列(BATS)和百慕大试验床系泊(BTM)--和新的海洋技术的同时，为研究海洋物理、生物和化学与物质通量之间的相互作用，以及这些相互作用又如何与大气和气候强迫相联系提供了无与伦比的机会。该项目预计将产生一些更广泛的影响：(1)系统的、长期的生物地球化学观测，例如OFP提供的观测，对于了解自然的海洋可变性和提供一个参考点以解释未来可能出现的气候变化情景的影响是必不可少的。(2)之前的NSF小组将OFP计划称为“社区资源”。该项目将继续与研究人员和学生共享其资源--样本材料、数据、辅助船运时间和系泊平台的使用--以极低的社区成本进行各种调查。(3)OFP样本档案是一笔不可多得的财富。将收集的样本材料将继续对当前和未来的生物地球化学和气候研究具有无价的价值。(4)OFP提供的教育经验将在关键时刻拓宽许多年轻研究人员的研究经验和视野。特别有价值的是有机会直接参与百慕大天文台的观测海洋学、时间序列研究和综合活动。

ABSTRACTOCE-0623505Understanding ocean variability over interannual and decadal time-scales is of widespread interest and increasing relevance given the concerns over anthropogenic perturbations on global climate due to increases in greenhouse gases. It is certain that ocean ecosystems will be affected by altered climate patterns, and an imperative exists to assess and model the ocean's response to possible climate change scenarios. This requires a fundamental understanding of how the ocean and its biota naturally respond to climate and environmental forcing variables. Ocean observation is a necessary first step. The contributions of long-term studies to our knowledge of how the ocean works are numerous and far-reaching. Yet, such studies are exceedingly rare- especially those with a biogeochemical focus. Since 1978, the Oceanic Flux Program (OFP) has continuously measured particle fluxes in the deep Sargasso Sea. The 28 year OFP time-series is, by far, the longest of its kind and unique in its focus on the deep ocean. OFP has produced a unique, albeit "edited", record of temporal variability in the "biological pump", a term loosely applied here to material transfer from the surface to the deep ocean. The OFP provided the first direct evidence for seasonality in the deep ocean and the tight coupling between deep fluxes and upper ocean processes. It has provided clear evidence of the intensity of biological reprocessing of flux and scavenging of suspended material in mesopelagic waters. The record has documented interannual and longer variations in deep fluxes and shorter term fluctuations driven by the interactions between mesoscale variability and meteorological forcing. The time-series is becoming long enough to begin study of variability in terms of multiyear basin-scale climatic forcing, such as the North Atlantic Oscillation. With funding from this award, researchers at the Bermuda Biological Station for Research and the Marine Biological Laboratory will continue operation of this unique and fundamental oceanographic time-series. As the record gets longer, we are better able to put into perspective the observed fluctuations in terms of the interplay between climate and ocean functioning. The concurrence of three co-coordinated and complementary time-series at Bermuda -- the OFP, the Bermuda Atlantic Time-Series (BATS) and the Bermuda Testbed Mooring (BTM) --and new ocean technology presents unparalleled opportunities to study the coupled interactions among ocean physics, biology and chemistry and material fluxes, and how these in turn are linked to atmospheric and climatic forcing. This project is expected to have a number of broader impacts: (1) Systematic, long-term biogeochemical observations, such as those provided by the OFP, are essential to gain an understanding of natural oceanic variability and to provide a reference point in which to interpret the repercussions of possible future climate change scenarios. (2) Previous NSF panels have termed the OFP program a "community resource". The project will continue to share its resources- sample material, data, ancillary shiptime, and use of the mooring platform- with researchers and students to make possible a diverse range of investigations at a very low cost to the community. (3) The OFP sample archive is a rare treasure. The sample material to be collected will continue to be invaluable for current and future biogeochemical and climate studies. (4) Educational experiences provided by the OFP will broaden the research experiences and horizons of many young research investigators at a critical juncture. Of particular value are opportunities to become directly involved with observational oceanography, time-series research and integrated activities of the Bermuda Observatory.