共查询到20条相似文献，搜索用时 18 毫秒
1.
The uptake of atmospheric carbon dioxide in the water transported over the Bering–Chukchi shelves has been assessed from the change in carbon-related chemical constituents. The calculated uptake of atmospheric CO2 from the time that the water enters the Bering Sea shelf until it reaches the northern Chukchi Sea shelf slope (1 year) was estimated to be 86±22 g C m−2 in the upper 100 m. Combining the average uptake per m3 with a volume flow of 0.83×106 m3 s−1 through the Bering Strait yields a flux of 22×1012 g C year−1. We have also estimated the relative contribution from cooling, biology, freshening, CaCO3 dissolution, and denitrification for the modification of the seawater pCO2 over the shelf. The latter three had negligible impact on pCO2 compared to biology and cooling. Biology was found to be almost twice as important as cooling for lowering the pCO2 in the water on the Bering–Chukchi shelves. Those results were compared with earlier surveys made in the Barents Sea, where the uptake of atmospheric CO2 was about half that estimated in the Bering–Chukchi Seas. Cooling and biology were of nearly equal significance in the Barents Sea in driving the flux of CO2 into the ocean. The differences between the two regions are discussed. The loss of inorganic carbon due to primary production was estimated from the change in phosphate concentration in the water column. A larger loss of nitrate relative to phosphate compared to the classical ΔN/ΔP ratio of 16 was found. This excess loss was about 30% of the initial nitrate concentration and could possibly be explained by denitrification in the sediment of the Bering and Chukchi Seas. 相似文献
2.
3.
The 3rd Chinese National Arctic Research Expedition(CHINARE–Arctic III) was carried out from July to September in 2008. The partial pressure of CO2(pCO2) in the atmosphere and in surface seawater were determined in the Bering Sea during July 11–27, 2008, and a large number of seawater samples were taken for total alkalinity(TA) and total dissolved inorganic carbon(DIC) analysis. The distributions of CO2 parameters in the Bering Sea and their controlling factors were discussed. The pCO2 values in surface seawater presented a drastic variation from 148 to 563 μatm(1 μatm = 1.013 25×10-1 Pa). The lowest pCO2 values were observed near the Bering Sea shelf break while the highest pCO2 existed at the western Bering Strait. The Bering Sea generally acts as a net sink for atmospheric CO2 in summer. The air-sea CO2 fluxes in the Bering Sea shelf, slope, and basin were estimated at-9.4,-16.3, and-5.1 mmol/(m2·d), respectively. The annual uptake of CO2 was about 34 Tg C in the Bering Sea. 相似文献
4.
Strong hydrographic controls on spatial and seasonal variability of dissolved organic carbon in the Chukchi Sea 总被引：1，自引：0，他引：1
Jeremy T. Mathis Dennis A. Hansell Nicholas R. Bates 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3245
A detailed analysis of dissolved organic carbon (DOC) distribution in the Western Arctic Ocean was performed during the spring and summer of 2002 and the summer of 2003. DOC concentrations were compared between the three cruises and with previously reported Arctic work. Concentrations of DOC were highest in the surface water where they also showed the highest degree of variability spatially, seasonally, and annually. Over the Canada Basin, DOC concentrations in the main water masses were: (1) surface layer (71±4 μM, ranging from 50 to 90 μM); (2) Bering Sea winter water (66±2 μM, ranging from 58 to 75 μM); (3) halocline layer (63±3 μM, ranging from 59 to 68 μM), (4) Atlantic layer (53±2 μM, ranging from 48 to 57 μM), and (5) deep Arctic layer (47±1 μM, ranging from 45 to 50 μM). In the upper 200 m, DOC concentrations were correlated with salinity, with higher DOC concentrations present in less-saline waters. This correlation indicates the strong influence that fluvial input from the Mackenzie and Yukon Rivers had on the DOC system in the upper layer of the Chukchi Sea and Bering Strait. Over the deep basin, there appeared to be a relationship between DOC in the upper 10 m and the degree of sea-ice melt water present. We found that sea-ice melt water dilutes the DOC signal in the surface waters, which is contrary to studies conducted in the central Arctic Ocean. 相似文献
5.
6.
David Kadko Robin Muench 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3227
Shelf–basin exchange in the western Arctic was evaluated by use of water-column analyses of 228Ra/226Ra ratios and the first measurements of the short-lived 224Ra (T1/2=3.64 d) in the Arctic. During the 2002 shelf–basin interaction (SBI) program, excess 224Ra was detected over the shelf but was not found seaward of the shelf-break. Similarly, the 228Ra/226Ra ratio dropped rapidly from the shelf across the shelf-break. Consequently, the model age gradient (elapsed time since shelf residence) northward across the Chukchi Shelf increased from 1–5 years nearshore to approximately 14 years in surface waters sampled off shelf at the southern margin of the Beaufort Gyre. This steep gradient is consistent with very slow exchange between the Chukchi Shelf and the Beaufort Gyre, whereby Bering Strait inflow is constrained by the Earth's rotation to follow local isobaths and does not easily move into deeper water. The strong dynamic control inhibiting water that enters the system through Bering Strait from flowing north across isobaths also would lead to a long recirculation time of river water emptied into the Beaufort Gyre. Possible mechanisms that can generate cross-shelf currents that break the topographic constraint to follow isobaths, and thereby transport water (and associated properties) off the shelves include wind-induced upwelling/downwelling, meandering jets, and eddies. Evidence of such a process was found during the ICEX project in the Beaufort Sea in April 2003 when excess 224Ra was measured over 200 km from any shelf source. This required an NE offshore flow of 40 cm s−1 assuming that the source water derives from the mouth of Barrow Canyon. A weak northeastward flow was measured using an LADCP within the upper 300 m of the ocean, but was of lower speed than required by the 224Raxs at the time of the ICEX occupation. 相似文献
7.
Dong-Chan Oh Mi-Kyung Park Sang-Hwa Choi Dong-Jin Kang Sun Young Park Jeom Shik Hwang Andrey Andreev Gi Hoon Hong Kyung-Ryul Kim 《Journal of Oceanography》1999,55(2):157-169
During CREAMS expeditions, fCO2 for surface waters was measured continuously along the cruise tracks. The fCO2 in surface waters in summer varied in the range 320–440 μatm, showing moderate supersaturation with respect to atmospheric
CO2. In winter, however, fCO2 showed under-saturation of CO2 in most of the area, while varying in a much wider range from 180 to 520 μatm. Some very high fCO2 values observed in the northern East Sea (Japan Sea) appeared to be associated with the intensive convection system developed
in the area. A gas-exchange model was developed for describing the annual variation of fCO2 and for estimating the annual flux of CO2 at the air-sea interface. The model incorporated annual variations in SST, the thickness of the mixed layer, gas exchange
associated with wind velocity, biological activity and atmospheric concentration of CO2. The model shows that the East Sea releases CO2 into the atmosphere from June to September, and absorbs CO2 during the rest of the year, from October through May. The net annual CO2 flux at the air-sea interface was estimated to be 0.032 (±0.012) Gt-C per year from the atmosphere into the East Sea. Water
column chemistry shows penetration of CO2 into the whole water column, supporting a short turnover time for deep waters in the East Sea.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
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
9.
V. M. Sergeeva I. N. Sukhanova M. V. Flint L. A. Pautova J. M. Grebmeier L. W. Cooper 《Oceanology》2010,50(2):184-197
The phytoplankton community was studied in Bering Strait and over the shelf, continental slope, and deep-water zones of the
Chukchi and Beaufort seas in the middle of the vegetative season (July–August 2003). Its structure was analyzed in relation
to ice conditions and the seasonal patterns of water warming, stratification, and nutrient concentrations. The overall ranges
of variation in phytoplankton abundance and biomass were estimated at 2.0 × 102 to 6.0 × 106 cells/l and 0.1 to 444.1 mg C/m3. The bulk of phytoplankton cells concentrated in the seasonal picnocline, at depths of 10–25 m. The highest values of cell
density and biomass were recorded in regions influenced by the inflow of Bering Sea waters or characterized by intense hydrodynamics,
such as the Bering Strait, Barrow Canyon, and the outer shelf and slope of the Chukchi Sea. In the middle of the vegetative
season, the phytoplankton in the study region of the Western Arctic proved to comprise three successional (seasonal) assemblages,
namely, the early spring, late spring, and summer assemblages. Their spatial distribution was dependent mainly on local features
of hydrological and nutrient regimes rather than on general latitudinal trends of seasonal succession characteristic of arctic
ecosystems. 相似文献
10.
Hengxiang Deng Hongwei Ke Peng Huang Xiaodan Chen Minggang Cai 《Journal of Oceanography》2018,74(5):439-452
The Arctic Ocean is connected to the Pacific by the Bering Sea and the Bering Strait. During the 4th Chinese National Arctic Research Expedition, measurements of carbon tetrachloride (CCl4) were used to estimate ventilation time-scales and anthropogenic CO2 (Cant) concentrations in the Arctic Ocean and Bering Sea based on the transit time distribution method. The profile distribution showed that there was a high-CCl4 tongue entering through the Canada Basin in the intermediate layer (27.6?<?σθ?<?28), at latitudes between 78 and 85°N, which may be related to the inflow of Atlantic water. Between stations B09 and B10, upwelling appeared to occur near the continental slope in the Bering Sea. The ventilation time scales (mean ages) for deep and bottom water in the Arctic Ocean (~?230–380 years) were shorter than in the Bering Sea (~?430–970 years). Higher mean ages show that ventilation processes are weaker in the intermediate water of the Bering Sea than in the Arctic Ocean. The mean Cant column inventory in the upper 4000 m was higher (60–82 mol m?2) in the Arctic Ocean compared to the Bering Sea (35–48 mol m?2). 相似文献
11.
The temperature minimum layer, called “dichothermal water”, is a characteristic feature of the North Pacific subarctic gyre.
In particular, dichothermal water having a density of approximately 26.6 sigma-theta (σθ), which corresponds to the densest water outcropping in winter in the North Pacific, is seen in the Bering Sea. In order
to clarify the water properties, and the area in which and the process by which the dichothermal water is formed, a new seasonal
mean gridded climatological dataset with a fine resolution for the Bering Sea and adjacent seas has been prepared using historically
accumulated hydrographic data. Although the waters of the Alaskan Stream have temperature minimum layers, their temperature
inversions are very weak in climatologies and the core densities of the temperature minimum layers are much lighter than 26.6σθ. On the other hand, in the Bering Sea one can see the robust structure of temperature minimum layers, the core density of
the dichothermal water being around 26.6σθ. In addition, it has been found that the properties of the dichothermal water observed in the warming season are almost the
same as those in the winter mixed layer. That is, the dichothermal waters are formed in the winter mixed layer in the Bering
Sea. Since these waters are found in the Kamchatka Strait, i.e., the main exit of the Bering Sea waters, it can be supposed
that the dichothermal waters are exported from the Bering Sea to the Pacific Ocean by the Kamchatka Current.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
A quasi-two dimensional model of the carbon and nitrogen cycling above the 70m isobath of the southeastern Bering Sea at 57°N replicates the observed seasonal cycles of nitrate, ammonium, ΣCO2, pCO2, light penetration, chlorophyll, phytoplankton growth rate, and primary production, as constrained by changes in wind, incident radiation, temperature, ice cover, vertical and lateral mixing, grazing stress, benthic processing of phytodetritus and zooplankton fecal pellets, and the pelagic microbial loop of DOC, bacteria, and their predators. About half of the seasonal resupply of nitrate stocks to their initial winter conditions is derived from in situ nitrification, with the rest obtained from deep-sea influxes. Under the present conditions of atmospheric forcing, shelf-break exchange, and food web structure, this shelf ecosystem serves as a sink for atmospheric CO2, with storage in the forms of exported DOC, DIC, and unutilized POC (phytoplankton, bacteria, and fecal pellets).As a consequence of just the rising levels of atmospheric pCO2 since the the Industrial Revolution, however, the biophysical CO2 status of the Southeastern Bering Sea shelf may have switched over the last 250 years, from a prior source to the present sink, since this relatively pristine ecosystem has unergone little eutrophication. Such fluctuations of CO2 status may thus be reversed by the physical processes of : (1) reduction of atmospheric pCO2, (2) increased on welling of deep-sea ΣCO2, and (3) warming of shelf waters. Based on our application of this model to the Chukchi Sea and the Gulf of Mexico, about 1.0–1.2 gigatons C y-1 of atmospheric CO2 may now be sequestered by temperate and polar shelf ecosystems. When tropical systems are included, however, a positive net sink of only 0.6–0.8. × 1015g C y−1 may prevail over all shelves. 相似文献
13.
In 1999, synoptic and hydrological conditions in the western Bering Sea were characterized by negative SST and air temperature anomalies, extensive ice coverage and late melting. Biological processes were also delayed. In 1999, the average zooplankton biomass was 1.76 g/m3, approximately half the average 3.07 g/m3 in 1998. Pacific salmon migrated to the northeastern Kamchatka streams two weeks later. This contrasts with 1997 (spring and summer) and 1998 (summer) when positive SST anomalies were widely distributed throughout the northwestern Bering Sea shelf. Since the second half of the 1990s, seasonal atmospheric processes developed over the western Bering Sea that were similar to those of the cold decades of the 1960–1970s. A meridional atmospheric circulation pattern began to replace zonal transport. Colder Arctic air masses have shifted over the Bering Sea region and shelf water temperatures have cooled considerably with the weakening of zonal atmospheric circulation. Temperature decreased in the cold intermediate layer during its renewal in winter. Besides, oceanic water inflow intensified into the Bering Sea in intermediate layers. Water temperature warmed to 4°C and a double temperature maximum existed in the warm intermediate layer in late summer in both 1997 and 1998. Opposing trends of cold water temperature and a warm intermediate layer led to an increase of vertical gradients in the main thermocline and progressing frontogenesis. It accelerates frontal transport and can be regarded as a chief cause of increased water exchange with the Pacific Ocean. 相似文献
14.
On the basis of the CTD data obtained within the Bering Sea shelf by the Second to Sixth Chinese National Arctic Research Expedition in the summers of 2003, 2008, 2010, 2012 and 2014, the classification and interannual variation of water masses on the central Bering Sea shelf and the northern Bering Sea shelf are analyzed. The results indicate that there are both connection and difference between two regions in hydrological features. On the central Bering Sea shelf, there are mainly four types of water masses distribute orderly from the slope to the coast of Alaska: Bering Slope Current Water(BSCW), MW(Mixed Water), Bering Shelf Water(BSW) and Alaska Coastal Water(ACW). In summer, BSW can be divided into Bering Shelf Surface Water(BSW_S) and Bering Shelf Cold Water(BSW_C). On the northern Bering Sea shelf near the Bering Strait,it contains Anadyr Water(AW), BSW and ACW from west to east. But the spatial-temporal features are also remarkable in each region. On the central shelf, the BSCW is saltiest and occupies the west of 177°W, which has the highest salinity in 2014. The BSW_C is the coldest water mass and warmest in 2014; the ACW is freshest and mainly occupies the east of 170°W, which has the highest temperature and salinity in 2012. On the northern Bering Sea shelf near the Bering Strait, the AW is saltiest with temperature decreasing sharply compared with BSCW on the central shelf. In the process of moving northward to the Bering Strait, the AW demonstrates a trend of eastward expansion. The ACW is freshest but saltier than the ACW on the central shelf,which is usually located above the BSW and is saltiest in 2014. The BSW distributes between the AW and the ACW and coldest in 2012, but the cold water of the BSW_C on the central shelf, whose temperature less than 0°C, does not exist on the northern shelf. Although there are so many changes, the respond to a climate change is synchronized in the both regions, which can be divided into the warm years(2003 and 2014) and cold years(2008, 2010 and 2012). The year of 2014 may be a new beginning of warm period. 相似文献
15.
Roles of Continental Shelves and Marginal Seas in the Biogeochemical Cycles of the North Pacific Ocean 总被引：4，自引：0，他引：4
Chen-Tung Arthur Chen Andrey Andreev Kyung-Ryul Kim Michiyo Yamamoto 《Journal of Oceanography》2004,60(1):17-44
Most marginal seas in the North Pacific are fed by nutrients supported mainly by upwelling and many are undersaturated with
respect to atmospheric CO2 in the surface water mainly as a result of the biological pump and winter cooling. These seas absorb CO2 at an average rate of 1.1 ± 0.3 mol C m−2yr−1 but release N2/N2O at an average rate of 0.07 ± 0.03 mol N m−2yr−1. Most of primary production, however, is regenerated on the shelves, and only less than 15% is transported to the open oceans
as dissolved and particulate organic carbon (POC) with a small amount of POC deposited in the sediments. It is estimated that
seawater in the marginal seas in the North Pacific alone may have taken up 1.6 ± 0.3 Gt (1015 g) of excess carbon, including 0.21 ± 0.05 Gt for the Bering Sea, 0.18 ± 0.08 Gt for the Okhotsk Sea; 0.31 ± 0.05 Gt for
the Japan/East Sea; 0.07 ± 0.02 Gt for the East China and Yellow Seas; 0.80 ± 0.15 Gt for the South China Sea; and 0.015 ±
0.005 Gt for the Gulf of California. More importantly, high latitude marginal seas such as the Bering and Okhotsk Seas may
act as conveyer belts in exporting 0.1 ± 0.08 Gt C anthropogenic, excess CO2 into the North Pacific Intermediate Water per year. The upward migration of calcite and aragonite saturation horizons due
to the penetration of excess CO2 may also make the shelf deposits on the Bering and Okhotsk Seas more susceptible to dissolution, which would then neutralize
excess CO2 in the near future. Further, because most nutrients come from upwelling, increased water consumption on land and damming
of major rivers may reduce freshwater output and the buoyancy effect on the shelves. As a result, upwelling, nutrient input
and biological productivity may all be reduced in the future. As a final note, the Japan/East Sea has started to show responses
to global warming. Warmer surface layer has reduced upwelling of nutrient-rich subsurface water, resulting in a decline of
spring phytoplankton biomass. Less bottom water formation because of less winter cooling may lead to the disappearance of
the bottom water as early as 2040. Or else, an anoxic condition may form as early as 2200 AD.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
对白令海表层海水228Ra的分析表明,白令海表层海水228Ra比活度从低于检测限变化至0.81 Bq/m3,低于西北冰洋陆架区的报道值。表层水228Ra比活度和228Ra/226Ra)A.R.的空间分布均呈现由西南部中心海盆向东北部陆架区增加的趋势。由228Ra/226Ra)A.R.和盐度的关系揭示出白令海环流、白令海陆坡流和阿拉斯加沿岸流对228Ra和228Ra/226Ra)A.R.分布有明显影响。运用一维稳态扩散模型计算出白令海由中心海盆向东北部陆架方向上水体混合的水平涡动扩散系数为1.9×108 m2/d。结合海盆-陆架界面营养盐的水平浓度梯度,估算得硝酸盐、活性磷酸盐和活性硅酸盐由白令海中心海盆向东北部陆架区的水平输送通量,该通量对白令海东北部陆架区新生产力的贡献很小,其他途径输送的营养盐更为重要。 相似文献
17.
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
18.
Laboratory measurements of all four CO2 parameters [fCO2 ( = fugacity of CO2), pH, TCO2 ( = total dissolved inorganic carbon), and TA ( = total alkalinity)] were made on the same sample of Gulf Stream seawater (S = 35) as a function of temperature (5–35 °C) and the ratio of TA/TCO2 (X) (1.0–1.2). Overall the measurements were consistent to ±8 μ atm in fCO2, ± 0.004 in pH, ± 3 μ mol kg−1 in TCO2, and ± 3 μ mol kg−1 in TA with the thermodynamic constants of Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995). Deviations between the measured pH, TCO2, TA and those calculated from various input combinations increase with increasing X when the same constants are used. This trend in the deviations indicates that the uncertainties in pK2 become important with increasing X (surface waters), but are negligible for samples with the lower X (deep waters). This trend is < 5 μ mol kg−1 when the pK2 values of Lee and Millero (1995) are used.The overall probable error of the calculated fCO2 due to uncertainties in the accuracy of the parameters (pH, TCO2, TA, pK0, pk1, and pK2) is ± 1.2%, which is similar to the differences between the measured values and those calculated using the thermodynamic constants of Millero (1995).The calculated values of pK1, (from fCO2-TCO2-TA) agree to within ± 0.004 compared to the results of Dickson and Millero (1987), Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995) over the same experimental conditions. The calculated values of pK2 (from pH-TCO2-TA) are in good agreement (± 0.004) with the results of Lee and Millero (1995) and also in reasonable agreement (± 0.008) with the results of Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995). The salinity dependence of our derived values of pK1 and pK2, (S = 35) can be estimated using the equations determined by Millero (1995). 相似文献
19.
Carbonate chemistry and projected future changes in pH and CaCO3 saturation state of the South China Sea 总被引：3，自引：0，他引：3
Chen-Tung Arthur Chen Shu-Lun Wang Wen-Chen Chou David D. Sheu 《Marine Chemistry》2006,101(3-4):277-305
To study the dissolved carbonate system in the South China Sea (SCS) and to understand the water mass exchange between the SCS and the West Philippine Sea (WPS), pH, total alkalinity and total CO2 were measured aboard the R/V Ocean Researcher 1. Because of the sill that separates these two seas in the Luzon Strait with a maximum depth of 2200 m, the SCS Deep Water has characteristics similar to those of water at about 2200 m in the WPS. The minimum pH and the maxima of normalized alkalinity and total CO2 commonly found in the open oceans at mid-depth also prevail in the WPS but are, however, very weak in the SCS. Rivers and inflows from Kuroshio Surface and Deep Waters through the Luzon Strait as well as those through the Mindoro Strait transport carbon to the SCS year-round. Meanwhile, the outflowing Taiwan Strait water as well as the SCS Surface and Intermediate Waters of the Luzon Strait transports carbon out of the SCS year-round. The Sunda Shelf is also a channel for carbon transport into the SCS in the wet season and out of the SCS in the dry season.fCO2 data and mass balance calculations indicate that the SCS is a weak CO2 source in the wet season but an even weaker CO2 sink in the dry season. With these facts taken together, the SCS is likely a very weak CO2 source. Anthropogenic CO2 penetrates to about 1500 m in depth in the SCS, and the entire SCS contains 0.60 ± 0.15 × 1015 g of excess carbon. Typical profiles of pH as well as the degree of saturation of each of calcite and aragonite in 1850 and 1997 are presented, and those for 2050 AD are projected. The maximum decrease in pH is estimated to be 0.16 pH units in the surface layer when the amount of CO2 is doubled. It is anticipated that aragonite in the upper continental slope will likely start to dissolve, thereby neutralizing excess CO2 by around 2050 AD. This paper is unique in that it presents the results of the first attempt ever to estimate the past, present and future physico-chemical properties of the world's largest marginal sea. 相似文献
20.
对中国第四次北极科学考察期间在白令海北部获取的海水样品进行悬浮体含量及其颗粒组分特征的分析。结果表明,白令海陆架海区悬浮体含量大体呈现出表层浓度低而底层浓度高的特点。表层海水悬浮体含量在白令海峡西侧和陆架东侧靠近阿拉斯加沿岸含量较高,而底层海水中悬浮体含量则在白令海峡西侧,以及白令海陆架西南部的圣马修岛西北侧较高。陆架流系对底床物质的再悬浮作用致使白令海悬浮颗粒物浓度的高值区多位于近底层海水中。受白令陆坡流沿陆架坡折带输运作用,研究区西南部悬浮体浓度较高。白令海陆架水以及阿纳德尔流携带悬浮颗粒向北输运,使得底层悬浮体浓度呈现出自南向北逐渐减弱的模式。圣劳仑斯岛以北靠近楚科奇半岛一侧海域,受高营养盐的阿纳德尔流的影响,悬浮颗粒物以藻类为主;东侧阿拉斯加沿岸流区悬浮颗粒则以陆源的碎屑矿物为主。 相似文献