共查询到20条相似文献，搜索用时 125 毫秒
1.
James P. Barry Kurt R. Buck Chris F. Lovera Linda Kuhnz Patrick J. Whaling Edward T. Peltzer Peter Walz Peter G. Brewer 《Journal of Oceanography》2004,60(4):759-766
Purposeful deep-sea carbon dioxide sequestration by direct injection of liquid CO2 into the deep waters of the ocean has the potential to mitigate the rapid rise in atmospheric levels of greenhouse gases.
One issue of concern for this carbon sequestration option is the impact of changes in seawater chemistry caused by CO2 injection on deep-sea ecosystems. The effects of deep-sea carbon dioxide injection on infaunal deep-sea organisms were evaluated
during a field experiment in 3600 m depth off California, in which liquid CO2 was released on the seafloor. Exposure to the dissolution plume emanating from the liquid CO2 resulted in high rates of mortality for flagellates, amoebae, and nematodes inhabiting sediments in close proximity to sites
of CO2 release. Results from this study indicate that large changes in seawater chemistry (i.e. pH reductions of ∼0.5–1.0 pH units)
near CO2 release sites will cause high mortality rates for nearby infaunal deep-sea communities.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Features of coastal upwelling regions that determine net air-sea CO<Subscript>2</Subscript> flux 总被引：1，自引：0，他引：1
Debby Ianson Richard A. Feely Christopher L. Sabine Lauren W. Juranek 《Journal of Oceanography》2009,65(5):677-687
The influence of the coastal ocean on global net annual air-sea CO2 fluxes remains uncertain. However, it is well known that air-sea pCO2 disequilibria can be large (ocean pCO2 ranging from ∼400 μatm above atmospheric saturation to ∼250 μatm below) in eastern boundary currents, and it has been hypothesized
that these regions may be an appreciable net carbon sink. In addition it has been shown that the high productivity in these
regions (responsible for the exceptionally low surface pCO2) can cause nutrients and inorganic carbon to become more concentrated in the lower layer of the water column over the shelf
relative to adjacent open ocean waters of the same density. This paper explores the potential role of the winter season in
determining the net annual CO2 flux in temperate zone eastern boundary currents, using the results from a box model. The model is parameterized and forced
to represent the northernmost part of the upwelling region on the North American Pacific coast. Model results are compared
to the few summer data that exist in that region. The model is also used to determine the effect that upwelling and downwelling
strength have on the net annual CO2 flux. Results show that downwelling may play an important role in limiting the amount of CO2 outgassing that occurs during winter. Finally data from three distinct regions on the Pacific coast are compared to highlight
the importance of upwelling and downwelling strength in determining carbon fluxes in eastern boundary currents and to suggest
that other features, such as shelf width, are likely to be important. 相似文献
3.
The method proposed for determining the total inorganic carbon (TC) concentrations in sea ice (Arctic region, North Pole-35
expedition) based on the measurement of the total alkalinity (TA) and the pH in the melt waters without the CO2 exchange with the atmosphere is considered. It is shown that the TC/Sal and TA/TC values through the entire ice section remain
similar to these parameters in the subice water. The surface snow and the uppermost ice layers are characterized by elevated
TA/TC values, which indicate the reaction Ca2+ + 2HCO3− = ↓CaCO3 + ↑CO2 + H2O. The release of CO2 to the atmosphere due to the decomposition of calcium hydrocarbonate is as high as ∼20 mmol/m2. The meltwater of the examined ice is undersaturated with CO2, which may result in a sink of atmospheric CO2 (∼30 mmol/m2). 相似文献
4.
Toru?Iwata Keiko?Yoshikawa Katsutoshi?Nishimura Yoshihisa?Higuchi Takao?Yamashita Shigeru?Kato Eiji?Ohtaki
The measurements of the vertical transport of CO2 were carried out over the Sea of Japan using the specially designed pier of Kyoto University on September 20 to 22, 2000. CO2 fluxes were measured by the eddy correlation and aerodynamic techniques. Both techniques showed comparable CO2 fluxes during sea breeze conditions: −0.001 to −0.08 mg m−2s−1 with the mean of −0.05 mg m−2s−1. This means that the measuring site satisfies the fetch requirement for meteorological observations under sea breeze conditions. Moreover, the eddy diffusivity coefficient used in the aerodynamic technique is found to be consistent with the coefficient used in the eddy correlation technique. The present result leads us to conclude that the aerodynamic technique may be applicable to underway CO2 flux measurements over the ocean and may be used in place of the bulk technique. The important point is the need to maintain a measuring accuracy of CO2 concentration difference of the order of 0.1 ppmv on the research vessels or the buoys. 相似文献
5.
Kevin R. Carman David Thistle John W. Fleeger James P. Barry 《Journal of Oceanography》2004,60(4):767-772
An experiment was performed to determine the effect of injected CO2 on the deep-sea (3200 m) meiofaunal community in the Monterey Canyon. Approximately 20 L of liquid CO2 was added to each of three cylindrical corrals (PVC rings pushed into the seabed) that were arranged in a triangular array
10 m on a side. After a 30-day period, sediment cores were collected within an area exposed to the dissolution plume emanating
from the CO2 pools and from a reference site approximately 40 m away; cores were also collected from within two of the CO2 corrals. Sediment cores were sectioned into 0–5, 5–10, and 10–20 mm layers. Abundances of major groups (harpacticoid copepods,
nematodes, nauplii, kinorhynchs, polychaetes, and total meiofauna) were determined for each layer. CO2 exposure did not significantly influence the abundances or vertical distributions of any of the major taxa. However, other
evidence suggests that abundance alone did not accurately reflect the effect of CO2 on meiofauna. We argue that slow decomposition rates of meiofaunal carcasses can mask adverse effects of CO2 and that longer experiments and/or careful examination of meiofaunal condition are needed to accurately evaluate CO2 effects on deep-sea meiofaunal communities.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Direct measurements of the air-sea CO2 flux by the eddy covariance technique were carried out in the equatorial Indian Ocean. The turbulent flux observation system
was installed at the top of the foremast of the R/V MIRAI, thus minimizing dynamical and thermal effects of the ship body.
During the turbulent flux runs around the two stations, the vessel was steered into the wind at constant speed. The power
spectra of the temperature or water vapor density fluctuations followed the Kolmogorov −5/3 power law, although that of the
CO2 density fluctuation showed white noise in the high frequency range. However, the cospectrum of the vertical wind velocity
and CO2 density was well matched with those of the vertical velocity and temperature or water vapor density in this frequency range,
and the CO2 white noise did not influence the CO2 flux. The raw CO2 fluxes due to the turbulent transport showed a sink from the air to the ocean, and had almost the same value as the source
CO2 fluxes due to the mean vertical flow, corrected by the sensible and latent heat fluxes (called the Webb correction). The
total CO2 fluxes including the Webb correction terms showed a source from the ocean to the air, and were larger than the bulk CO2 fluxes estimated using the gas transfer velocity by mass balance techniques. 相似文献
7.
Ulf Riebesell 《Journal of Oceanography》2004,60(4):719-729
Rising atmospheric CO2 and deliberate CO2 sequestration in the ocean change seawater carbonate chemistry in a similar way, lowering seawater pH, carbonate ion concentration
and carbonate saturation state and increasing dissolved CO2 concentration. These changes affect marine plankton in various ways. On the organismal level, a moderate increase in CO2 facilitates photosynthetic carbon fixation of some phytoplankton groups. It also enhances the release of dissolved carbohydrates,
most notably during the decline of nutrient-limited phytoplankton blooms. A decrease in the carbonate saturation state represses
biogenic calcification of the predominant marine calcifying organisms, foraminifera and coccolithophorids. On the ecosystem
level these responses influence phytoplankton species composition and succession, favouring algal species which predominantly
rely on CO2 utilization. Increased phytoplankton exudation promotes particle aggregation and marine snow formation, enhancing the vertical
flux of biogenic material. A decrease in calcification may affect the competitive advantage of calcifying organisms, with
possible impacts on their distribution and abundance. On the biogeochemical level, biological responses to CO2 enrichment and the related changes in carbonate chemistry can strongly alter the cycling of carbon and other bio-active elements
in the ocean. Both decreasing calcification and enhanced carbon overproduction due to release of extracellular carbohydrates
have the potential to increase the CO2 storage capacity of the ocean. Although the significance of such biological responses to CO2 enrichment becomes increasingly evident, our ability to make reliable predictions of their future developments and to quantify
their potential ecological and biogeochemical impacts is still in its infancy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Feasibility studies recently suggest that sequestration of anthropogenic CO2 in the deep ocean could help reduce the atmospheric CO2 concentration. However, implementation of this strategy could have a significant environmental impact on marine organisms.
This has highlighted the urgent need of further studies concerning the biological impact of CO2 ocean sequestration. In this paper we summarize the recent literature reporting on the biological impact of CO2 and discuss the research work required for the future. Although fundamental research of the effect of CO2 on marine organisms before the practical consideration of CO2 ocean sequestration was limited, laboratory and field studies concerning biological impacts have been increasing after the
first international workshop in 1991 discussing CO2 ocean sequestration. Acute impacts of CO2 ocean sequestration could be determined by laboratory and field experiments and assessed by simulation models as described
by the following papers in this section. On the other hand, chronic effects of CO2 ocean sequestration, those directly related to the marine ecosystem, would be difficult to verify by means of experiments
and to assess using ecosystem models. One of the practical solutions for this issue implies field experiments starting with
controlled small scale and eventually to a large scale of CO2 injection intended to determine ecosystem alteration.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Peter G. Brewer Edward T. Peltzer Gernot Friederich Izuo Aya Kenji Yamane 《Marine Chemistry》2000,72(2-4)
We have carried out a series of in situ experiments to investigate the formation of a CO2 hydrate (CO2:5.75 H2O) for the purpose of evaluating scenarios for ocean fossil fuel CO2 disposal with a solid hydrate as the sequestered form. The experiments were carried out with a remotely operated vehicle in Monterey Bay at a depth of 619 m. pH measurements made in close proximity to the hydrate–seawater interface showed a wide range of values, depending upon the method of injection and the surface area of the hydrate formed. Rapid injection of liquid CO2 into an inverted beaker to form a flocculant mass of hydrate resulted in pH initially as low as 4.5 within a few centimeters of the interface, decaying slowly over 1–2 h towards normal seawater values as dense CO2 rich brine drained from the hydrate mass. In a second experiment, slower injection of the liquid CO2 to produce a simple two-layer system with a near planar interface of liquid CO2 with a thin hydrate film yielded pH values indistinguishable from the in situ ocean background level of 7.6. Both field and laboratory results now show that the dissolution rate of a mass of CO2 hydrate in seawater is slow but finite. 相似文献
10.
Fugacity of CO2 (fCO2), temperature, salinity, nutrients, and chlorophyll-a were measured in the surface waters of southwestern East Sea/Japan Sea in July 2005. Surface waters were divided into three
waters based on hydrographic characteristics: the water with moderate sea surface temperature (SST) and high sea surface salinity
(SSS) located east of the front (East water); the water with high SST and moderate SSS located west of the front (West water);
and the water with low SST and SSS located in the middle part of the study area (Middle water). High fCO2 larger than 420 μatm were found in the West water. In the Middle water, CO2 was undersaturated with respect to the atmosphere, with values between 246 and 380 μatm. Moderate fCO2 values ranging from 370 to 420 μatm were observed in the East water. For the East and West waters, estimates of temperature
dependency of fCO2 (12.6 and 15.1 μatm °C−1, respectively) were rather similar to a theoretical value, indicating that SST is likely to be a major factor controlling
the surface fCO2 distribution in these two regions. In the Middle water, however, the estimated temperature dependence was somewhat lower
than the theoretical value, and relatively high concentrations of surface chlorophyll-a coincided with the low surface fCO2, implying that biological uptake may considerably affect the fCO2 distribution. The net sea-to-air CO2 flux of the study area was estimated to be 0.30±4.81 mmol m−2 day−1 in summer, 2005. 相似文献
11.
Yoshiyuki Nakano Hideshi Kimoto Shuichi Watanabe Koh Harada Yutaka W. Watanabe 《Journal of Oceanography》2006,62(1):71-81
We have developed new systems capable of profiling to >1000 m for measuring in situ pH and fugacity of CO2 (fCO2) in the ocean using spectrophotometric analysis (pH and CO2 profilers). The in situ pH is determined by detecting the color change of the pH indicator (m-cresol purple). It can withstand ambient pressure to 1000 m depth. The CO2 profiler analyzed in situ fCO2 by detecting the change of pH in an inner solution, equilibrated with the seawater through a gas permeable membrane. It can
be operated to 2500 m depth. We used an amorphous fluoropolymer tubing form of AF-2400 for the gas permeable membrane due
to its high gas permeability coefficients. The inner solution was a mixture of 2 μM bromocresol purple (BCP) and 5 μM sodium
hydroxide. This system gave us a response time of 1 minute, which is twice as fast as previous systems. The precisions of
pH and CO2 profilers were within 0.002 and 2.5% respectively. We have used these profilers to study the North Pacific, obtaining good
agreement with the difference between the data from profilers and a discrete bottle of 0.002 ± 0.005 pH (SE, n = 25) and −0.4
± 3 μatm (SE, n = 31). 相似文献
12.
Environmental challenges such as ocean acidification and eutrophication influence the physiology of kelp species. We investigated their interactive effects on Saccharina japonica (Laminariales, Phaeophyta) under two pH conditions [Low, 7.50; High (control), 8.10] and three NH 4 + concentrations (Low, 4; Medium, 60; High, 120 μM). The degree of variation of pH values in the culture medium and inhibition rate of photosynthetic oxygen evolution by acetazolamide were affected by pH treatments. Relative growth rates, carbon, nitrogen, and the C:N ratio in tissue samples were influenced by higher concentrations of NH 4 + . Rates of photosynthetic oxygen evolution were enhanced under elevated CO2 or NH 4 + conditions, independently, but these two factors did not show an interactive effect. However, rates of NH 4 + uptake were influenced by the interactive effect of increased CO2 under elevated NH 4 + treatment. Although ocean acidification and eutrophication states had an impact on physiological performance, chlorophyll fluorescence was not affected by those conditions. Our results indicated that the physiological reactions by this alga were influenced to some extent by a rise in the levels of CO2 and NH 4 + . Therefore, we expect that the biomass accumulation of S. japonica may well increase under future scenarios of ocean acidification and eutrophication. 相似文献
13.
In order to examine temporal variations of the surface oceanic and atmospheric fCO2 and the DIC concentration, we analyzed air and seawater samples collected during the period May 1992–June 1996 in the northwestern
North Pacific, about 30 km off the coast of the main island of Japan. The atmospheric CO2 concentration has increased secularly at a rate of 1.9 ppmv yr−1, and it showed a clear seasonal cycle with a maximum in spring and a minimum late in summer, produced mainly by seasonally-dependent
terrestrial biospheric activities. DIC also showed a prominent seasonal cycle in the surface ocean; the minimum and maximum
values of the cycle appeared in early fall and in early spring, respectively, due primarily to the seasonally-dependent activities
of marine biota and partly to the vertical mixing of seawater and the coastal upwelling. The oceanic fCO2 values were almost always lower than those of the atmospheric fCO2, suggesting that this area of the ocean acts as a sink for atmospheric CO2. Values varied seasonally, mainly reflecting seasonal changes of SST and DIC, with a secular increase at a rate of 3.7 μatm
yr−1. The average values of the annual net CO2 flux between the ocean and the atmosphere calculated by using the different bulk equations ranged between −0.8 and −1.7 mol
m−2yr−1, and its magnitude was enhanced and reduced late in spring and mid-summer, respectively, due mainly to the seasonally varying
oceanic fCO2. 相似文献
14.
热液喷口附近的羽状流中存在明显的化学及浊度异常,通过探测这些异常可判断是否存在热液喷口及确定喷口的具体位置。本文研制了一款可用于探测热液喷口的多通道化学传感器,该传感器具有体积小、精度高的特点,且可在4000米深海中进行工作。该化学传感器共配备五个全固态电极,一个为参比电极,其余四个为离子选择性电极,并且可根据所测量的化学离子进行更换。本文基于该化学传感器共进行了两组实验。在第一组浅海试验中,化学传感器集成了pH,Eh,CO32-和SO42-电极,在浅海海域中测量对应化学量,结果表明该化学传感器可在实际应用中获得高精度、稳定的测量数据。第二组实验为深海热液探测,装配了pH,Eh,CO32-和H2S电极的化学传感器在西南印度洋中脊区域的29次测线中投入使用,共获得有效数据27组。通过对测量所得到的化学量进行分析,本文提出了一种确定热液喷口的化学异常探测方法,若某时间段内Eh和H2S的电势降低,而pH和CO32-的电势上升则可判定存在化学异常。利用该方法对27组有效数据进行分析,共发现5个潜在的热液喷口。实验结果表明,该化学传感器可有效地探测由热液引起的化学异常,适用于实际热液探测中。 相似文献
15.
The responses of atmospheric pCO2 and sediment calcite content to changes in the export rain ratio of calcium carbonate to organic carbon are examined using
a diffusion-advection ocean biogeochemical model coupled to a one-dimensional sediment geochemistry model. Our model shows
that a 25% reduction in rain ratio decreases atmospheric pCO2 by 59 ppm. This is caused by alkalinity redistribution by a weakened carbonate pump and an alkalinity increase in the whole
ocean via carbonate compensation with decreasing calcite burial. The steady state responses of sedimentary calcite content
and calcite preservation efficiency are rather insensitive to the deepening of the saturation horizon of 1.9 km. This insensitivity
is a result of the reduced deposition flux that decreases calcite burial, counteracting the saturation horizon deepening that
increases calcite burial. However, in the first 10,000 years the effect of reduced calcite deposition on the burial change
is more prominent; while after 10,000 years, the effect of saturation horizon deepening is more dominant. The lowering of
sediment calcite content for the first 10,000 years is effectively decoupled from the 1.9 km downward shift of the saturation
horizon. Our results are in part a consequence of the more dominant role that respiration CO2 plays in sediment calcite dissolution over bottom water chemistry in our control run and support the decoupling of calcite
lysocline depth and saturation horizon shifts, as suggested originally by Archer and Maier-Reimer (1994) and Archer et al. (2000). 相似文献
16.
To study the biological impacts of CO2 ocean sequestration on floating marine organisms, a full Eulerian-Eulerian scheme model has been developed in a large-eddy
simulation (LES) version using one-way coupling of the equations of seawater flow to the transport equations of the bio-scalar
variables. Special attention was paid to deriving the transport equation, involving non-conservative scalars to describe the
degree of injury to floating organisms due to the change in the pH environment resulting from CO2 dissolution. The source terms of the transport equations of bio-scalar variables are based on experimental data on zooplankton
activities affected by lower pH seawater, allowing construction of empirical sub-models of three kinds of floating marine
organisms: Gaidius variabilis, Paraeuchaeta Birostrata, and Multi-organisms. An example is given to show the applicability
of the model to the assessment of the biological impact of CO2 sequestration in the ocean. Given an initial CO2 droplet diameter of 8.0 mm and an injection rate of 1.0 kg/sec, the model simulation predicts that the zooplanktons lose
approximately 90% of their activity when the lowest pH inside the plume decreases from 7.57 to 5.61. These injured zooplanktons
then recovered gradually to their normal state within two hours due to dilution of the plume.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
本文在实验室模拟近期海洋酸化水平,对海洋酸化对海水青鳉鱼(Oryzia melastigma)胚胎骨骼发育的影响进行了初步研究。实验中,通过往实验水体中充入一定浓度CO2气体酸化海水。对照组CO2分压为450×10-6,两个处理组CO2浓度分别为1 160×10-6和1 783×10-6,对应的水体pH值分别为8.14,7.85和7.67。将海水青鳉鱼受精卵放入实验水体中至仔鱼孵化出膜,对初孵仔鱼经骨骼染色、显微拍照,挑取了仔鱼头部、躯干及尾部骨骼染色清晰的28个骨骼参数的长度进行了显微软件测量及数据统计分析。结果发现,酸化处理对实验鱼所测量的骨骼长度影响均不显著。因此推测,未来100~200年间海洋酸化对海水青鳉鱼的胚胎及初孵仔鱼的骨骼发育没有显著影响。 相似文献
18.
Data on the NO2 content in the vertical column of the atmosphere obtained with the Ozone Monitoring Instrument (OMI) aboard the EOS Aura
satellite (United States) in the period from October 2004 to October 2007 are compared with the results of ground-based measurements
at the Zvenigorod Scientific Station (55.7° N, 36.8° E). The “unpolluted”; part of the total NO2 content in the atmospheric column, which mostly represents the stratosphere, and the NO2 contents in the vertical column of the troposphere, including the lower layer, which is subject to pollution, are included
in the comparison. The correlation coefficient between the results of ground-based and satellite measurements of the “unpolluted”
total NO2 content is ∼0.9. The content values measured with the OMI instrument are smaller than the results of ground-based measurements
(on average, by (0.30 ± 0.03) × 1015 cm−2 or by (11 ± 1)%). Therms discrepancy between the satellite and ground-based data is 0.6 × 1015 cm−2. The NO2 content in the vertical column of the troposphere from the results of satellite measurements is, on average, (1.4 ± 0.5)
× 1015 cm−2, (or about 35%) smaller than from the results of ground-based measurements, and the rms discrepancy between them is about
200%. The correlation coefficient between these data is ∼0.4. This considerable discrepancy is evidently caused by the strong
spatial (horizontal) inhomogeneity and the temporal variability of the NO2 field during episodes of pollution, which leads to different (and often uncorrelated) estimates of the NO2 content in the lower troposphere due to different spatial resolutions of ground-based and satellite measurements. 相似文献
19.
The ecological consequences of ocean acidification are unclear due to varying physiological properties of macroalgae and species-specific responses. Therefore, in the present study, we used a laboratory culture experiment to analyse the eco-physiological responses of the Mediterranean subtidal red alga Peyssonnelia squamaria to CO2-induced lower pH. Our results showed an increase in the photosynthetic performance and growth rate of P. squamaria, despite the reduction in CaCO3 content in the low pH treatment. According to our results, we believe that samples exposed to elevated CO2 could be regulated own nitrogen metabolism to support increased growth rate and it may be down-regulated nitrate uptake. As a result, we hypothesize that P. squamaria may benefit from ocean acidification. 相似文献
20.
Atsushi Ishimatsu Takashi Kikkawa Masahiro Hayashi Kyoung-Seon Lee Jun Kita 《Journal of Oceanography》2004,60(4):731-741
CO2-enriched seawater was far more toxic to eggs and larvae of a marine fish, silver seabream, Pagrus major, than HCl-acidified seawater when tested at the same seawater pH. Data on the effects of acidified seawater can therefore
not be used to estimate the toxicity of CO2, as has been done in earlier studies. Ontogenetic changes in CO2 tolerance of two marine bony fishes (Pag. major and Japanese sillago, Sillago japonica) showed a similar, characteristic pattern: the cleavage and juvenile stages were most susceptible, whereas the preflexion
and flexion stages were much more tolerant to CO2. Adult Japanese amberjack, Seriola quinqueradiata, and bastard halibut, Paralichthys olivaceus, died within 8 and 48 h, respectively, during exposure to seawater equilibrated with 5% CO2. Only 20% of a cartilaginous fish, starspotted smooth-hound, Mustelus manazo, died at 7% CO2 within 72 h. Arterial pH initially decreased but completely recovered within 1-24 h for Ser. quinqueradiata and Par. olivaceus at 1 and 3% CO2, but the recovery was slower and complete only at 1% for M. manazo. During exposure to 5% CO2, Par. olivaceus died after arterial pH had been completely restored. Exposure to 5% CO2 rapidly depressed the cardiac output of Ser. quinqueradiata, while 1% CO2 had no effect. Both levels of ambient CO2 had no effect on blood O2 levels. We tentatively conclude that cardiac failure is important in the mechanisms by which CO2 kills fish. High CO2 levels near injection points during CO2 ocean sequestration are likely to have acute deleterious effects on both larvae and adults of marine fishes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献