Temporal Variation in Organic Carbon Utilization by the Deep-Sea Sediment Community at the Hawaii Ocean Time-Series Station

发起了全球海洋通量联合研究（JGOFS），以在天到几十年的时间尺度上研究海洋碳循环。建立了两个长时间序列站，一个在北大西洋，一个在北太平洋，以代表广阔的亚热带海洋环流。虽然已经花费了相当大的努力来解决这两个站上层水柱中的碳循环问题，但对海底的碳通量基本上仍未进行研究。特别令人感兴趣的是地表水有机碳的生产和输出与深海沉积物群落对有机碳的利用之间的耦合。在大西洋和太平洋中，表面产生的颗粒物质以偶发脉冲的形式快速输送到深海海底。这些偶发事件叠加在一年中沉降到海底的颗粒物质的缓慢“雨”上。一旦这些物质到达海底，它就会被组成沉积物群落的生物进行生化转化。沉积物生物群利用有机质的速率可以通过测量沉积物群落耗氧量（SCOC）来估计。我们将在JGOFS夏威夷海洋时间序列站（ALOHA站）测量SCOC。利用漫游者的独特能力（一种独特的、自主的、底部横断面的车辆），我们将解决以下问题：1)根据SCOC估计，沉积物群落对有机碳的利用在几天到几个月的时间尺度上是否存在时间变异性？并且，考虑到夏威夷海洋时间序列计划（HOT）中其他研究者收集的数据，2)沉积物群落对有机碳的利用与通过水柱的颗粒物的产生和向下通量之间是否存在时间关系？这些测量将在两年的时间内以前所未有的时间分辨率进行，与其他研究人员正在进行的对表面生产力、向下颗粒通量和其他各种上层海洋参数的监测相一致。这一联合努力将构成第一个长时间序列研究，以类似的高时间分辨率提供从地表水到深海海底的全套测量数据。这项研究的结果将对模拟深海的碳循环有价值。

The Joint Global Ocean Flux Study (JGOFS) was initiated to study the oceanic carbon cycle on time scales of days to decades. Two long time series stations were established, one in the North Atlantic and one in the North Pacific, to represent the expansive subtropical oceanic gyres. Although considerable effort has been expended to resolve the cycling of carbon in the upper water column at these two stations, the fluxes of carbon at the sea floor remain largely unstudied. Of particular interest is the coupling between the production and export of organic carbon from surface waters and the utilization of organic carbon by the deep sea sediment community. Rapid transport of surface derived particulate matter in episodic pulses to the abyssal sea floor occurs in both the Atlantic and Pacific Oceans. These episodic events are superimposed on a slower `rain` of particulate matter sinking to the sea floor throughout the year. Once this material reaches the sea floor, it is transformed biochemically by the organisms comprising the sediment community. The rate at which this organic matter is utilized by the sediment biota can be estimated by measuring sediment community oxygen consumption (SCOC). We will measure SCOC at the JGOFS Hawaii Ocean Time series station (Station ALOHA). Using the unique capabilities of the ROVER (a unique, autonomous, bottom-transecting vehicle), we will address the following questions: 1) Is there temporal variability in the utilization of organic carbon by the sediment community, as estimated from SCOC, on time scales of days to months? And, considering data collected by other investigators in the Hawaii Ocean Time series program (HOT), 2) is there a temporal relationship between the utilization of organic carbon by the sediment community and the production and downward flux of particulate matter through the water column? These measurements will be made with unprecedented temporal resolution over a two year period, in concert with ongoing monitoring by other investigators of surface productivity, downward particulate fluxes, and a variety of other upper ocean parameters. This combined effort will constitute the first long time series study to provide such a complete suite of measurements from surface waters to the abyssal sea floor with similar, high temporal resolution. The results of this study will be valuable for modeling carbon cycling at the deep sea floor.