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1.
Like most other deep basins in Southeast Asia, the deep Sulu Sea (SS) basin is isolated from the neighboring seas by surrounding topography. While the near-surface circulation is mainly governed by the seasonally reversing monsoon winds, below the warm and fresh surface layer, the core of the incoming Subtropical Lower Water from the West Philippine Sea (WPS), by way of the South China Sea (SCS), can be seen, at a depth of around 200 m, to have a distinct salinity maximum. It lies well above the sill depth (420 m) in the Mindoro Strait and thus, its spreading is not hampered by topography. The deep circulation is forced by an inflow of upper North Pacific Intermediate Water (NPIW) from the SCS through the Mindoro Str. Below 1000 m, the physico-chemical properties are remarkably homogeneous. The higher temperature, but lower salinity, oxygen and nutrients, of the deep SS waters, compared to those of the SCS, is indicative of the intrusion of NPIW above the sill depth. The excess, anthropogenic CO2 penetrates the entire water column, because of the over-spill of the excess CO2-laden water from the SCS.It has been reported that the bottom of the SS is CaCO3 rich, relative to the SCS. Previous investigators attribute this to the higher θ in the SS. Indeed, the aragonite does not become undersaturated in the SS until below 1400 m, compared to 600 m in both the WPS and SCS; and the calcite does not become undersaturated until below 3800 m in the SS, compared to 2500 m in the SCS and around 1600 m in the WPS. However, the temperature effect is relatively small. These large differences are, in fact, largely a result of higher CO32− concentrations in the SS, relative to the WPS and SCS. The higher CO32− concentration in the SS, in turn, is mainly caused by the smaller amounts of organic carbon decomposition.  相似文献   

2.
南海东北部春季海表pCO_2分布及海-气CO_2通量   总被引：1，自引：1，他引：0  
2013年南海东北部春季共享航次采用走航观测方式,现场测定了表层海水和大气的二氧化碳分压(pCO2)及相应参数。结合水文、化学等同步观测要素资料,对该海域pCO2的分布变化进行了探讨。结果表明,陆架区受珠江冲淡水、沿岸上升流及生物活动的影响,呈现CO2的强汇特征;吕宋海峡附近及吕宋岛西北附近海域受海表高温、黑潮分支"西伸"、吕宋岛西北海域上升流等因素影响,呈现强源特征。根据Wanninkhof的通量模式,春季整个南海东北部海域共向大气释放约4.25×104 t碳。  相似文献   

3.
This paper evaluates the simultaneous measurement of dissolved gases (CO2 and O2/Ar ratios) by membrane inlet mass spectrometry (MIMS) along the 180° meridian in the Southern Ocean. The calibration of pCO2 measurements by MIMS is reported for the first time using two independent methods of temperature correction. Multiple calibrations and method comparison exercises conducted in the Southern Ocean between New Zealand and the Ross Sea showed that the MIMS method provides pCO2 measurements that are consistent with those obtained by standard techniques (i.e. headspace equilibrator equipped with a Li–Cor NDIR analyser). The overall MIMS accuracy compared to Li–Cor measurements was 0.8 μatm. The O2/Ar ratio measurements were calibrated with air-equilibrated seawater standards stored at constant temperature (0 ± 1 °C). The reproducibility of the O2/Ar standards was better than 0.07% during the 9 days of transect between New Zealand and the Ross Sea.The high frequency, real-time measurements of dissolved gases with MIMS revealed significant small-scale heterogeneity in the distribution of pCO2 and biologically-induced O2 supersaturation (ΔO2/Ar). North of 65°S several prominent thermal fronts influenced CO2 concentrations, with biological factors also contributing to local variability. In contrast, the spatial variation of pCO2 in the Ross Sea gyre was almost entirely attributed to the biological utilization of CO2, with only small temperature effects. This high productivity region showed a strong inverse relationship between pCO2 and biologically-induced O2 disequilibria (r2 = 0.93). The daily sea air CO2 flux ranged from − 0.2 mmol/m2 in the Northern Sub-Antarctic Front to − 6.4 mmol/m2 on the Ross Sea shelves where the maximum CO2 influx reached values up to − 13.9 mmol/m2. This suggests that the Southern Ocean water (south of 58°S) acts as a seasonal sink for atmospheric CO2 at the time of our field study.  相似文献   

4.
The seasonal and interannual variability of the air–sea CO2 flux (F) in the Atlantic sector of the Barents Sea have been investigated. Data for seawater fugacity of CO2 (fCO2sw) acquired during five cruises in the region were used to identify and validate an empirical procedure to compute fCO2sw from phosphate (PO4), seawater temperature (T), and salinity (S). This procedure was then applied to time series data of T, S, and PO4 collected in the Barents Sea Opening during the period 1990–1999, and the resulting fCO2sw estimates were combined with data for the atmospheric mole fraction of CO2, sea level pressure, and wind speed to evaluate F.The results show that the Atlantic sector of the Barents Sea is an annual sink of atmospheric CO2. The monthly mean uptake increases nearly monotonically from 0.101 mol C m− 2 in midwinter to 0.656 mol C m− 2 in midfall before it gradually decreases to the winter value. Interannual variability in the monthly mean flux was evaluated for the winter, summer, and fall seasons and was found to be ± 0.071 mol C m− 2 month− 1. The variability is controlled mainly through combined variation of fCO2sw and wind speed. The annual mean uptake of atmospheric CO2 in the region was estimated to 4.27 ± 0.68 mol C m− 2.  相似文献   

5.
彭鹏飞  马媛  史荣君  王迪  许欣  颜彬 《海洋科学》2022,46(10):140-149
根据2018年7月、11月和2019年1月、4月对广东考洲洋牡蛎养殖海域进行4个季节调查获得的pH、溶解无机碳(DIC)、水温、盐度、溶解氧(DO)及叶绿素a(Chla)等数据,估算该区域表层海水溶解无机碳体系各分量的浓度、初级生产力(PP)、表层海水CO2分压[p(CO2)]和海-气界面CO2交换通量(FCO2),分析牡蛎养殖活动对养殖区碳循环的影响。结果表明:牡蛎养殖区表层海水中Chla、DIC、HCO3–和PP显著低于非养殖区;养殖淡季表层海水中pH、DO、DIC、HCO3–、和CO32–显著大于养殖旺季,养殖旺季的p(CO2)和FCO2显著大于养殖淡季。牡蛎养殖区表层海水夏季、秋季、冬季和春季的海-气界面CO2交换通量FCO2平均值分别是(42.04±9.56)、(276.14±52.55)、(–11.59±18.15)和(–13.02±6.71)mmol/(m2·d),冬季各站位FCO2值离散度较大,其中位数是–10.73mmol/(m2·d)。在全年尺度,表层海水p(CO2)及FCO2与水温呈显著正相关,与盐度呈显著负相关。在非养殖区,浮游植物光合作用可能对影响表层海水p(CO2)及FCO2起主导作用。养殖牡蛎钙化、呼吸作用等生理因素释放的CO2对表层海水p(CO2)及FCO2未产生显著影响。考洲洋养殖海域养殖旺季为CO2的源,养殖淡季整体为CO2的弱汇。  相似文献   

6.
Excess CO2 and pHexcess showing an increase in dissolved inorganic carbon and a decrease in pH from the beginning of the industrial epoch (middle of the 19th century) until the present time have been calculated in the intermediate water layer of the northwestern Pacific and the Okhotsk Sea. It is concluded that: (1) The Kuril Basin (Okhotsk Sea) and the Bussol' Strait areas are characterized by the greatest concentrations of excess CO2 at isopycnal surfaces due to the processes of formation and transformation of intermediate water mass. (2) The largest difference in excess CO2 concentration between the Okhotsk Sea and the western subarctic Pacific (about 8 µmol/kg) is found at the = 27.0. (3) The difference in excess CO2 between the western subarctic Pacific and subtropical regions is significant only in the upper part of the intermediate water layer ( = 26.7–27.0). (4) About 10% of the excess CO2 accumulation in the subtropical north Pacific is determined by water exchange with the subarctic Pacific and the Okhotsk Sea.  相似文献   

7.
In the summers of 1999 and 2003, the 1st and 2nd Chinese National Arctic Research Expeditions measured the partial pressure of CO2 in the air and surface waters (pCO2) of the Bering Sea and the western Arctic Ocean. The lowest pCO2 values were found in continental shelf waters, increased values over the Bering Sea shelf slope, and the highest values in the waters of the Bering Abyssal Plain (BAP) and the Canadian Basin. These differences arise from a combination of various source waters, biological uptake, and seasonal warming. The Chukchi Sea was found to be a carbon dioxide sink, a result of the increased open water due to rapid sea-ice melting, high primary production over the shelf and in marginal ice zones (MIZ), and transport of low pCO2 waters from the Bering Sea. As a consequence of differences in inflow water masses, relatively low pCO2 concentrations occurred in the Anadyr waters that dominate the western Bering Strait, and relatively high values in the waters of the Alaskan Coastal Current (ACC) in the eastern strait. The generally lower pCO2 values found in mid-August compared to at the end of July in the Bering Strait region (66–69°N) are attributed to the presence of phytoplankton blooms. In August, higher pCO2 than in July between 68.5 and 69°N along 169°W was associated with higher sea-surface temperatures (SST), possibly as an influence of the ACC. In August in the MIZ, pCO2 was observed to increase along with the temperature, indicating that SST plays an important role when the pack ice melts and recedes.  相似文献   

8.
The complicated flow pattern in the intermediate layer of the Luzon Strait could directly affect the efficiency of the water and energy exchange between the South China Sea (SCS) and the North Pacific. Here we present a subsurface anticyclonic eddy in the Luzon Strait deduced using observations conducted in October 2005. On the basis of the hydrographic and current measurements, an anticyclonic eddy was found in the intermediate layer, i.e., about 26.8–27.3σθ, 500–900 m. It captures part of the SCS Intermediate Water outflow in the northern Luzon Strait, and carries it to flow southward and then westward back into the SCS in the southern Luzon Strait, with volume transport of about 1.9 × 106 m3 s−1. The simulated results from Hybrid Coordinate Ocean Model also suggest the existence of this anticyclonic eddy that develops and lingers for a month long.  相似文献   

9.
南海北部春季非水华期的CO_2分压及其调控   总被引：1，自引：0，他引：1  
翟惟东 《海洋学报》2015,37(6):31-40
针对南海北部和吕宋海峡附近海域的海-气CO2通量及其调控问题,研究了2009年3月底至4月中旬在这些海域通过走航观测的方法取得的海-气CO2分压和海表温度、盐度等相关数据。结果表明,在河口、沿岸流以外的南海北部开阔海域,与大气平衡的CO2分压分布在368~380μatm,南低北高,平均值为371μatm;而海表CO2分压分布在293~405μatm,南高北低。南海北部开阔海域的海表CO2分压主要受温度效应调控,也在一定程度上受水团混合、海-气交换、生物活动等非温度效应的影响。在相同水温条件下,黑潮区的海表CO2分压比南海北部的海表CO2分压低。本研究和大多数前人研究的结果都表明,南海北部海盆区域和吕宋海峡西侧海域在春季与大气CO2接近源汇平衡,而非大气CO2的显著源区。  相似文献   

10.
Marginal seas play important roles in regulating the global carbon budget, but there are great uncertainties in estimating carbon sources and sinks in the continental margins. A Pacific basin-wide physical-biogeochemical model is used to estimate primary productivity and air-sea CO_2 flux in the South China Sea(SCS), the East China Sea(ECS), and the Yellow Sea(YS). The model is forced with daily air-sea fluxes which are derived from the NCEP2 reanalysis from 1982 to 2005. During the period of time, the modeled monthly-mean air-sea CO_2 fluxes in these three marginal seas altered from an atmospheric carbon sink in winter to a source in summer. On annualmean basis, the SCS acts as a source of carbon to the atmosphere(16 Tg/a, calculated by carbon, released to the atmosphere), and the ECS and the YS are sinks for atmospheric carbon(–6.73 Tg/a and –5.23 Tg/a, respectively,absorbed by the ocean). The model results suggest that the sea surface temperature(SST) controls the spatial and temporal variations of the oceanic pCO_2 in the SCS and ECS, and biological removal of carbon plays a compensating role in modulating the variability of the oceanic pCO_2 and determining its strength in each sea,especially in the ECS and the SCS. However, the biological activity is the dominating factor for controlling the oceanic pCO_2 in the YS. The modeled depth-integrated primary production(IPP) over the euphotic zone shows seasonal variation features with annual-mean values of 293, 297, and 315 mg/(m~2·d) in the SCS, the ECS, and the YS, respectively. The model-integrated annual-mean new production(uptake of nitrate) values, as in carbon units, are 103, 109, and 139 mg/(m~2·d), which yield the f-ratios of 0.35, 0.37, and 0.45 for the SCS, the ECS, and the YS, respectively. Compared to the productivity in the ECS and the YS, the seasonal variation of biological productivity in the SCS is rather weak. The atmospheric pCO_2 increases from 1982 to 2005, which is consistent with the anthropogenic CO_2 input to the atmosphere. The oceanic pCO_2 increases in responses to the atmospheric pCO_2 that drives air-sea CO_2 flux in the model. The modeled increase rate of oceanic pCO_2 is0.91 μatm/a in the YS, 1.04 μatm/a in the ECS, and 1.66 μatm/a in the SCS, respectively.  相似文献   

11.
In order to understand the influence of the South China Sea (SCS) water on the Kuroshio, and to study the dissolved carbonate system, we participated in six WOCE cruises aboard R/V Ocean Researcher 1. The areas studied were the northeast South China Sea and the West Philippine Sea near the Luzon Strait. Temperature, salinity, pH, alkalinity and total CO2 were measured. Our data indicate that, although the Kuroshio and the SCS waters flow in and out of the Luzon Strait near surface, the SCS water seems mainly to flow out of the SCS at mid-depth. There exists a mid-depth front near 122°E between 350 and 1350 m in all seasons and years that we studied. The water mass between 350 and 1350 m east of the front belongs to the West Philippine Sea proper water, while on the west is the mixed water of the South China Sea and the West Philippine Sea.  相似文献   

12.
The role of coastal lagoons and estuaries as sources or sinks of inorganic carbon in upwelling areas has not been fully understood. During the months of May–July, 2005, we studied the dissolved inorganic carbon system in a coastal lagoon of northwestern Mexico during the strongest period of upwelling events. Along the bay, different scenarios were observed for the distributions of pH, dissolved inorganic carbon (DIC) and apparent oxygen utilization (AOU) as a result of different combinations of upwelling intensity and tidal amplitude. DIC concentrations in the outer part of the bay were controlled by mixing processes. At the inner part of the bay DIC was as low as 1800 μmol kg−1, most likely due to high water residence times and seagrass CO2 uptake. It is estimated that 85% of San Quintín Bay, at the oceanic end, acted as a source of CO2 to the atmosphere due to the inflow of CO2-rich upwelled waters from the neighboring ocean with high positive fluxes higher than 30 mmol C m−2 d−1. In contrast, there was a net uptake of CO2 and HCO3− by the seagrass bed Zostera marina in the inner part of the bay, so the pCO2 in this zone was below the equilibrium value and slightly negative CO2 fluxes of −6 mmol C m−2 d−1. Our positive NEP and ΔDIC values indicate that Bahía San Quintín was a net autotrophic system during the upwelling season during 2005.  相似文献   

13.
An improved model is presented for the calculation of the solubility of carbon dioxide in aqueous solutions containing Na+, K+, Ca2+, Mg2+, Cl−, and SO42− in a wide temperature–pressure–ionic strength range (from 273 to 533 K, from 0 to 2000 bar, and from 0 to 4.5 molality of salts) with experimental accuracy. The improvements over the previous model [Duan, Z. and Sun, R., 2003. An improved model calculating CO2 solubility in pure water and aqueous NaCl solutions from 273 to 533K and from 0 to 2000 bar. Chemical Geology, 193: 257–271] include: (1) By developing a non-iterative equation to replace the original equation of state in the calculation of CO2 fugacity coefficients, the new model is at least twenty times computationally faster and can be easily adapted to numerical reaction-flow simulator for such applications as CO2 sequestration and (2) By fitting to the new solubility data, the new model improved the accuracy below 288 K from 6% to about 3% of uncertainty but still retains the high accuracy of the original model above 288 K. We comprehensively evaluate all experimental CO2 solubility data. Compared with these data, this model not only reproduces all the reliable data used for the parameterization but also predicts the data that were not used in the parameterization. In order to facilitate the application to CO2 sequestration, we also predicted CO2 solubility in seawater at two-phase coexistence (vapor–liquid or liquid–liquid) and at three-phase coexistence (CO2 hydrate–liquid water–vapor CO2 [or liquid CO2]). The improved model is programmed and can be downloaded from the website http://www.geochem-model.org/programs.htm.  相似文献   

14.
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   

15.
Calcification in the marine environment is the basis for the accretion of carbonate in structures such as coral reefs, algal ridges and carbonate sands. Among the organisms responsible for such calcification are the Corallinaceae (Rhodophyta), recognised as major contributors to the process world-wide. Hydrolithon sp. is a coralline alga that often forms rhodoliths in the Western Indian Ocean. In Zanzibar, it is commonly found in shallow lagoons, where it often grows within seagrass beds and/or surrounded by green algae such as Ulva sp. Since seagrasses in Zanzibar have recently been shown to raise the pH of the surrounding seawater during the day, and since calcification rates are sensitive to pH, which changes the saturation state of calcium carbonate, we measured the effects of pH on photosynthetic and calcification rates of this alga. It was found that pH had significant effects on both calcification and photosynthesis. While increased pH enhanced calcification rates both in the light and in the dark at pH >8.6, photosynthetic rates decreased. On the other hand, an increase in dissolved CO2 concentration to 26 μmol kg−1 (by bubbling with air containing 0.9 mbar CO2) caused a decrease in seawater pH which resulted in 20% less calcification after 5 days of exposure, while enhancing photosynthetic rates by 13%. The ecological implications of these findings is that photosynthetically driven changes in water chemistry by surrounding plants can affect calcification rates of coralline algae, as may future ocean acidification resulting from elevated atmospheric CO2.  相似文献   

16.
The interannual variations of CO2 sources and sinks in the surface waters of the Antarctic Ocean (south of 50°S) were studied between 1986 and 1994. An existing, slightly modified one-dimensional model describing the mixed-layer carbon cycle was used for this study and forced by available satellite-derived and climatological data. Between 1986 and 1994, the mean Antarctic Ocean CO2 uptake was 0.53 Pg C year−1 with an interannual variability of 0.15 Pg C year−1.Interannual variation of the Antarctic Ocean CO2 uptake is related to the Antarctic Circumpolar Wave (ACW), which affects sea surface temperature (SST), wind-speed and sea-ice extent. The CO2 uptake in the Antarctic Ocean has increased from 1986 to 1994 by 0.32 Pg C. It was found that over the 9 years, the surface ocean carbon dioxide fugacity (fCO2) increase was half that of the atmospheric CO2 increase inducing an increase of the air–sea fCO2 gradient. This effect is responsible for 60% of the Antarctic Ocean CO2 uptake increase between 1986 and 1994, as the ACW effect cancels out over the 9 years investigated.  相似文献   

17.
We report several biogeochemical parameters (dissolved inorganic carbon (DIC), total alkalinity (TA), dissolved oxygen (DO), phosphate (PO4), nitrate + nitrite (NO3 + NO2), silicate (Si(OH)4)) in a region off Otaru coast in Hokkaido, Japan on a “weekly” basis during the period of April 2002–May 2003. To better understand the long-term temporal variations of the main factors affecting CO2 flux in this coastal region and its role as a sink/source of atmospheric CO2, we constructed an algorithm of DIC and TA using other hydrographic properties. We estimated the CO2 flux across the air–sea interface by using the classical bulk method. During 1998–2003 in our study region, the estimated fCO2sea ranged about 185–335 μatm. The maximum of fCO2sea in the summer was primarily due to the change of water temperature. The minimum of fCO2sea in the early spring can be explained not only by the change of water temperature but also the change of nutrients and chlorophyll-a. To clarify the factors affecting fCO2sea (water temperature, salinity, and biological activity), we carried out a sensitivity analysis of these effects on the variation of fCO2sea. In spring, the biological effect had the largest effect for the minimum of fCO2sea (40%). In summer, the water temperature effect had the largest effect for the maximum of fCO2sea (25%). In fall, the water temperature effect had the largest effect for the minimum of fCO2sea (53%). In winter, the biological effect had the largest effect for the minimum of fCO2sea (35%).We found that our study region was a sink region of CO2 throughout a year (−0.78 mol/m2/yr). Furthermore, we estimated that the increase of fCO2sea was about 0.56 μatm/yr under equilibrium with the atmospheric CO2 content for the period 1998–2003, with the temporal changes in the variables (T, S, PO4) on fCO2sea, thus as the maximum trend of each variable on fCO2sea was 0.22 μatm/yr, and the trend of residual fCO2 including gas exchange was 0.34 μatm/yr. This result suggests that interaction among variables would affect gas exchange between air and sea effects on fCO2sea. We conclude that this study region as a representative coastal region of marginal seas of the North Pacific is special because it was measured, but there is no particular significance in comparison to any other area.  相似文献   

18.
We observed the partial pressure of oceanic CO2, pCO2 sea, and related surface properties in the westernmost region of the subarctic North Pacific, seasonally from 1998 to 2001. The pCO2 sea in the Oyashio region showed a large decrease from winter to spring. In winter, pCO2 sea was higher than 400 μatm in the Oyashio region and this region was a source of atmospheric CO2. In spring, pCO2 sea decreased to extremely low values, less than 200 μatm (minimum, 139 μatm in 2001), around the Oyashio region with low surface salinity and this region turned out to be a strong sink. The spatial variations of pCO2 sea were especially large in spring in this region. The typical Oyashio water with minimal mixing with subtropical warm water was extracted based on the criterion of potential alkalinity. The contribution of main oceanic processes to the changes in pCO2 sea from winter to spring was estimated from the changes in the concentrations of dissolved inorganic carbon and nutrients, total alkalinity, temperature and salinity observed in surface waters in respective years. These quantifications indicated that photosynthesis made the largest contribution to the observed pCO2 sea decreases in all years and its magnitude was variable year by year. These year-to-year differences in spring biological contribution could be linked to those in the development of the density stratification due to the decrease in surface salinity. Thus, the changes in the surface physical structure could induce those in pCO2 sea in the Oyashio region in spring. Furthermore, it is suggested that the direction and magnitude of the air-sea CO2 flux during this season could be controlled significantly by the onset time of the spring bloom. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
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   

20.
Measurements of pCO2, pH and alkalinity in the surface waters of an iron fertilised patch of sub-Antarctic water were made during SAGE (SOLAS SAGE: Surface-Ocean Lower Atmosphere Studies Air-Sea Gas Experiment). The iron addition induced a minor phytoplankton bloom, however the patch dynamics were dominated by physical processes which suppressed and masked the biological effects. The Lagrangian nature of the experiment allowed the carbonate chemistry in the patch to be followed for 15.5 days, and the relative importance of the biological and physical factors influencing the surface water pCO2 was estimated. The pCO2 of the surface waters of the patch increased from 327 ??atm prior to iron addition to 338 ??atm on Day 14, effects of vertical and horizontal mixing offset the 15 ??atm drawdown that would have occurred had the induced biological uptake been the sole factor to influence the pCO2. The air-sea carbon flux calculated using the measured skin temperature and a piston velocity parameterisation determined during SAGE (Ho et al., 2006) was 98.5% of the flux determined using conventional bulk temperature measurement and the Wanninkhof (1992) piston velocity parameterisation. The skin temperature alone contributed to an 8% increase in the flux compared with that determined using bulk temperature.  相似文献   

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