Model simulations of carbon sequestration in the northwest Pacific by patch fertilization     

Katsumi Matsumoto 《Journal of Oceanography》2006,62(6):887-902

Iron fertilization of nutrient-rich surface waters of the ocean is one possible way to help slow the rising levels of atmospheric CO₂ by sequestering it in the oceans via biological carbon export. Here, I use an ocean general circulation model to simulate a patch of nutrient depletion in the subpolar northwest Pacific under various scenarios. Model results confirm that surface fertilization is an inefficient way to sequester carbon from the atmosphere (Gnanadesikan et al., 2003), since only about 20% of the exported carbon comes initially from the atmosphere. Fertilization reduces future production and thus CO₂ uptake by utilizing nutrients that would otherwise be available later. Effectively, this can be considered as leakage when compared to a control run. This “effective” leakage and the actual leakage of sequestered CO₂ cause a significant, rapid decrease in carbon retention (only 30–45% retained after 10 years and less than 20% after 50 years). This contrasts markedly with the almost 100% retention efficiency for the same duration using the same model, when carbon is disposed directly into the northwest Pacific (Matsumoto and Mignone, 2005). As a consequence, the economic effectiveness of patch fertilization is poor in two limiting cases of the future price path of carbon. Sequestered carbon in patch fertilization is lost to the atmosphere at increasingly remote places as time passes, which would make monitoring exceedingly difficult. If all organic carbon from one-time fertilization reached the ocean bottom and remineralized there, acidification would be about −0.05 pH unit with O₂ depletion about −20 μmol kg⁻¹. These anomalies are probably too small to seriously threaten deep sea biota, but they are underestimated in the model because of its large grid size. The results from this study offer little to advocate purposeful surface fertilization as a serious means to address the anthropogenic carbon problem.  相似文献   

Carbon cycling through the pelagic foodweb in the northern Humboldt Current off Chile (23{degrees}S)     

Gonzalez  H.E.; Giesecke  R.; Vargas  C.A.; Pavez  M.; Iriarte  J.; Santibanez  P.; Castro  L.; Escribano  R.; Pages  F. 《ICES Journal of Marine Science》2004,61(4):572-584

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喀斯特荒漠化是一种地质—生态灾难   总被引：23，自引：0，他引：23  

杨汉奎 《海洋地质与第四纪地质》1995,15(3):137-147

ＫＤＮ是一种ＧＥＯＬ－ＥＣＯＬ灾难,是发生潮湿的碳酸盐岩区的土壤侵蚀、土地退化与生态系统凋萎,致使人类很难生活在其中。ＫＤＮ是我国四大ＧＥＯＬ－ＥＣＯＬ灾害中最难整治、最难摆脱贫困的地区。本文按国际公认的原则为准,认定“石山化”≠ＫＤＮ,从地质结构性气候、物候和生态系统多因子厘定了ＫＤＮ术语,认定人为扰动与人口超载是其产生的序参量。其过程最迟也是３００多年前明清朝代屯垦开始,近半个世纪加速衰竭,森  相似文献   

滤食性贝类在对虾综合养殖生态系统中的作用   总被引：6，自引：0，他引：6  

吴桂汉  陈品健  江瑞胜 《台湾海峡》2001,20(4):447-452

就混养虾池中滤食性贝类如何影响虾池整个生态系统这个问题，综合了国内外这方面的文献，从滤食性贝类对混养虾池的水质、底质和其中的浮游植物、浮游动物的影响，以及混养对养殖效益的影响这几个方面作了探讨。  相似文献   

Topographic Effect of Izu Ridge on the Distribution of the North Pacific Intermediate Water South of Japan     

Yoshihiko Sekine  Shingo Watanabe  Fukuji Yamada 《Journal of Oceanography》2000,56(4):429-438

The topographic effect of the Izu Ridge on the horizontal distribution of the North Pacific Intermediate Water (NPIW) south of Japan has been studied using observational data obtained by the Seisui-Maru of Mie University (Mie Univ. data) and those compiled by Japan Oceanographic Data Center (JODC data). Both data sets show that water of salinity less than 34.1 psu on potential density () surface of 26.8 is confined to the eastern side of the Izu Ridge, while water of salinity less than 34.2 psu is confined to the southern area over the Izu Ridge at a depth greater than 2000 m and to the southeastern area in the Shikoku Basin. It is also shown by T-S analysis of Mie Univ. data over the Izu Ridge that water of salinity less than 34.2 psu dominates south of 30°N, where the depth of the Izu Ridge is deeper than 2000 m and NPIW can intrude westward over the Izu Ridge. JODC data reveal that relatively large standard deviations of the salinity on surface of 26.7, 26.8 and 26.9 are detected along the mean current path of the Kuroshio and the Kuroshio Extension. Almost all of the standard deviations are less than 0.05 psu in other area with the NPIW, which shows that the time variation in the salinity can be neglected. This observational evidence shows that the topographic effect of the Izu Ridge on the horizontal distribution of the NPIW, which is formed east of 145°E by the mixing of the Kuroshio water and the Oyashio water, is prominent north of 30°N with a depth shallower than 2000 m.  相似文献   

郯庐断裂带的断裂活动对渤海东部中、新生代裂谷盆地发育的控制作用     

李桂群  李学伦 《中国海洋大学学报(自然科学版)》1988,(4)

郯庐断裂带自南而北穿越渤海东部,自中生代中期至新生代中期表现裂谷发育特征。裂谷发育经历两个旋回,各旋回的裂谷发育演化、盆地分布格局,沉积相带,沉积补偿速度等均受断裂带的断裂活动的强烈控制。  相似文献   

秋茄和榕树叶片中正构烷烃分布和单体化合物δ13C值及其光合作用   总被引：1，自引：0，他引：1  

李宝才  董玉莲  李超  周建元  闻克威  盛国英  傅家谟 《热带海洋学报》2003,22(1):62-69

对深圳福田、阳江、海南新竹红树林秋茄Kandelia candel及海口榕树Ficusm icrocarpa叶中类脂物进行萃取,分离出正构烷烃,通过气相色谱(GC)及色谱-质谱(GC MS)分析,测出了正构烷烃的碳数分布和相对含量.气相色谱-稳定同位素比质谱仪(GC-IRMS)测定了正构烷烃单体化合物的稳定同位素组成δ13C.秋茄叶和榕树叶正构烷烃的碳数分布均为C17C33,主要集中在C23-C31(＞90%).化合物含量最高为C27的有深圳福田秋茄、海南新竹秋茄、海口榕树,而阳江秋茄为C25.单体化合物的稳定同位素δ13C深圳福田秋茄为-31.42‰-34.48‰,阳江秋茄为-31.69‰-33.62‰,海南新竹秋茄为-30.30‰-33.04‰,海口榕树为-29.92‰33.56‰;平均值分别为-32.95‰、32.67‰、31.67‰、-31.74‰.结果表明,秋茄和陆地植物榕树的光合作用都是通过C3途径,是典型C3植物.  相似文献   

赤道东北太平洋沉积物中生物钡的分布特征     

倪建宇  张美  周怀阳 《海洋地质与第四纪地质》2006,26(2):49-54

分析了赤道东北太平洋海域沉积物中Ba、Ti、Al和有机碳(Corg)的含量。研究表明,研究区沉积物中钡为0.198%~0.792%;采用标准陆源物质扣除法获得的生物钡(Babio)的含量为0.162%~0.764%,占沉积物中总钡含量的81.6%~96.5%,平均为88.7%,其在沉积物中的分布表现为上部一致,下部变化较大;有机碳(Corg)的含量为0.18%~0.58%,并表现为随沉积物深度的增加而降低。沉积物中Babio/Ti的比值表现为东区高于西区,且向高纬度降低的特点,而沉积物中Corg/Ti和Babio/Ti则表现为负相关关系,表明研究区沉积物中钡可能和上层海洋生产力的相关性不明显。  相似文献   

Validity of sea surface temperature observed with the TRITON buoy under diurnal heating conditions     

Yoshimi Kawai  Hiroshi Kawamura  Sumio Tanba  Kentaro Ando  Kunio Yoneyama  Norio Nagahama 《Journal of Oceanography》2006,62(6):825-838

In order to investigate the validity of buoy-observed sea surface temperature (SST), we installed special instruments to measure near-surface ocean temperature on the TRITON buoy moored at 2.07°N, 138.06°E from 2 to 13 March 2004, in addition to a standard buoy sensor for the regular SST measurement at 1.5-m depth. Large diurnal SST variations were observed during this period, and the variations of the temperatures at about 0.3-m depth could be approximately simulated by a one-dimensional numerical model. However, there was a notable discrepancy between the buoy-observed 1.5-m-depth SST (SST_1.5m) and the corresponding model-simulated temperature only during the daytime when the diurnal rise was large. The evaluation of the heat balance in the sea surface layer showed that the diurnal rise of the SST_1.5m in these cases could not be accounted for by solar heating alone. We examined the depth of the SST_1.5m sensor and the near-surface temperature observed from a ship near the buoy, and came to the conclusion that the solar heating of the buoy hull and/or a disturbance in the temperature field around the buoy hull would contribute to the excessive diurnal rise of the SST_1.5m observed with the TRITON buoy. However, the temperature around the hull was not sufficiently homogenized, as suggested in a previous paper. For the diurnal rise of the SST_1.5m exceeding 0.5 K, the daytime buoy data became doubtful, through dynamics that remain to be clarified. A simple formula is proposed to correct the unexpected diurnal amplitude of the buoy SST_1.5m.  相似文献   

The POC / Th ratio of settling particles isolated using split flow-thin cell fractionation (SPLITT)     

rjan Gustafsson  Jenny Larsson  Per Andersson  Johan Ingri 《Marine Chemistry》2006,100(3-4):314

The common assumption that the ratio between particulate organic carbon (POC) and particulate ²³⁴Th obtained from shallow sediment traps and filterable particles are representative of the ratio in the total particle settling flux should be treated with caution in view of well-known biases associated with tethered shallow sediment traps and the decoupling between size and settling velocity of many natural particle regimes. To make progress toward reliably constraining the POC / ²³⁴Th ratio on truly settling particles, we have tested here a settling collection technique designed to remove any hydrodynamic bias; split flow-thin cell fractionation (SPLITT). These first results from a North Sea fjord and an open Baltic Sea time-series station indicates that the POC / ²³⁴Th ratio on the more complete particle-settling spectrum, isolated with SPLITT, was higher than the POC / ²³⁴Th ratio obtained simultaneously from tethered shallow sediment traps in seven out of seven parallel deployments with an average factor of 210%. The POC / ²³⁴Th ratio from the SPLITT was either in the same range or higher than that obtained on filtered “bulk” particles. To explain this novel data we hypothesize that the slowest settling fraction is organic-matter rich and does not strongly complex ²³⁴Th (i.e., high POC / ²³⁴Th). We suggest that this ultra-slow sinking fraction is better collected by SPLITT than with tethered sediment traps because of minimized hydrodynamic bias.This was tested using the ratio of POC / Al as a tracer of detrital mineral-ballast influenced settling velocity. The higher POC / Al ratios in SPLITT samples relative to in traps is consistent with the hypothesis that SPLITT is better suited for collecting also the slow-settling component of sinking particles. This important slow-settling component appears to here consist primarily of non-APS/TEP components of plankton exudates or other less-strongly ²³⁴Th-complexing organic matter. Further applications of the SPLITT technique are likely to return increasingly new insights on the composition (including “truly settling” POC / ²³⁴Th) of the total spectrum of particles settling out of the upper ocean.  相似文献