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南黄海西部的陆架锋及冷水团锋区环流结构的初步研究 总被引：28，自引：8，他引：28
本文依据1984年7月的实测水文资料和卫星图片,指出了南黄海西部存在着因潮混合形成的浅水陆架锋,分析了陆架锋区的水文结构,指出在冷水团锋面区域海洋上层存在着一个因下层冷水上升而形成的低温、高盐、高氧带,沿陆架锋及冷水团边界区域,是黄海的主要上升流区。本文还指出,夏季黄海沿岸流主要是一支沿黄海冷水团锋面南下的强流(jet)。在冷水团衰退时期,随着冷水团的退缩,这一沿锋面的流动将向外海推移。 相似文献
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东海中陆架晚第四纪底栖有孔虫定量分析 总被引：5，自引：0，他引：5
利用东海中陆架EY02-1孔的柱状样品对底栖有孔虫动物群进行了定量分析研究，结合Q型因子分析及AMS“C测年数据，对东海中陆架古水团演化进行了初步探讨。Q型因子分析得到5个主因子．方差累积贡献为84．9％，这5个有孔虫组合在钻孔相关层位上反映特定的古水团特征。主因子1为Elphidium magellanicum组合，代表低温低盐沿岸水团(5～10m)；主因子2为Bolivina robusta组合，代表中陆架水团(50～100m)；主因子3为Protelphidium tuberculatum组合，代表外延的古黄海冷水团；主因子4为Florilus decorus组合,代表内陆架水团(0～50m)；主因子5为Epistominella naraensis组合，代表水体较凉的水深大于30m的内陆架水团。结果表明，冰后期以古长江冲淡水为主体的低温低盐沿岸水团、中陆架水团及内陆架水团交替影响EY02-1孔附近中陆架。在氧同位素3期以古长江冲淡水为主体的东海沿岸流与外延的古黄海冷水团控制着有孔虫组合。在氧同位素5a-5c期间，EY02-1孔附近中陆架可能已受到古黄海冷水团的影响。该孔顶部11．4m含大量贝壳的细砂沉积可能对应氧同位素1期U2层潮流沙脊脊部沉积，细砂平均沉积速率高达0.877mm／a。 相似文献
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黄海潮生陆架锋的分布 总被引：4，自引：0，他引：4
潮汐的搅拌作用,即潮混合,常常在中纬度陆架浅海中形成一种重要的水文现象——浅水陆架锋,亦称潮汐锋。黄海是一个半封闭的中纬度陆架浅海,水温的季节变化非常显著。黄海的潮能消耗又非常可观。据此,作者指出:夏季黄海的层化现象与潮混合有关;年复一年,黄海冷水团边界基本稳定,并且在冷水团边界附近海面总是存在着一些冷水分布,这类现象也是由潮混合形成的;由于近岸冷水的形成,在黄海冷水团边界附近海面还存在着浅水陆 相似文献
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本文研究了2008年7月黄海冷水团海域可培养细菌的多样性。AODC和DVC计数总菌数和活菌数分别为(1.3~4.8)×105/mL和(0.6~1.6)×105/mL;2216E平板以菌落计数法可培养细菌浓度为(0.56~2.2)×103cfu/mL。从分离到的475株中选取163株进行16S rDNA扩增,并用HhaⅠ酶进行ARDRA(扩增性rDNA限制酶切片段分析)多态性分析,取114株不同带型测序。结果显示,冷水团细菌归为4个细菌类群:变形菌门(Proteobacteria)、放线菌门(Acti-nobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes),共24个属,其中包括α-,β-,γ-变形菌纲;非冷水团细菌也归为这4个门类,共15个属,但未分离到β-变形菌纲。γ-变形菌纲在冷水团和非冷水团区域的不同深度都是优势菌群,不同的是冷水团区域α-变形菌纲比例较高(26.8%),而非冷水团区域α-变形菌纲比例相对较低(15.6%)。这表明黄海冷水团和非冷水团区域细菌多样性都很丰富,但其群落组成和优势菌群有所不同。此外,16S rDNA测序结果表明,6株细菌可能为海洋细菌新种。 相似文献
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黄海南部及东海北部夏季若干水文特征 总被引：17，自引：2，他引：17
本文就近几年作者在黄海南部和东海北部进行调查研究(夏季)的主要成果予以阐述,结论为:(1)南黄海底层冷水可进一步划分为三个次级水团;(2)潮混合对黄海冷水团边界和黄海温跃层等有重要影响,它还形成海面的陆架锋;(3)夏季南黄海上层存在着闭合的密度环流,而黄海沿岸流性质上属锋面强流,济州岛西南存在着气旋式海水运动;(4)黄海暖流不再深入黄海冷水团内部,但其内部可能存在着方向相反的一对弱环流;(5)长江口海区存在着可能是因台湾暖流逆坡行进产生的上升流现象。 相似文献
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黄海冷水团的变化特征 总被引：3，自引：2，他引：3
本文根据1957—1967,1972—1973和1975—1985这24年的温、盐度资料,利用“相似系数”法分析了夏季(8月)黄海冷水团分布范围、低温中心、体积和温、盐特性的多年变化。结果表明,黄海冷水团的分布范围具有比较明显的年间变化,强年的“相对体积”约为弱年的2.2倍。黄海冷水团的温、盐性质比较稳定,多年最大变幅分别为7.7℃和2.58‰。三个低温中心温、盐度的多年变幅,盐度以北黄海低温中心为最大(约1‰),温度以南黄海西侧低温中心最显著(3.51℃);而南黄海东侧低温中心温、盐度的变幅最小,分别为1.58℃和0.63‰。 相似文献
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本文根据t957—1967,1972—1973和1975—1985这24年的温、盐度资料,利用“相似系数”法分析了夏季(8月)黄海冷水团分布范围、低温中心、体积和温、盐特性的多年变化。结果表明,黄海冷水团的分布范围具有比较明显的年间变化,强年的“相对体积”约为弱年的2.2倍。黄海冷水团的温、盐性质比较稳定,多年最大变幅分别为7.7℃和2.58‰。三个低温中心温、盐度的多年变幅,盐度以北黄海低温中心为最大(约1‰),温度以南黄海西侧低温中心最显著(3.51℃);而南黄海东侧低温中心温、盐度的变幅最小,分别为1.58℃和0.63‰。 相似文献
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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
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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
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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
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The hydrographic and bio-optical properties of the Bering Sea shelf were analyzed based on in-situ measurements obtained during four cruises from 2007 to 2009. According to the temperature and salinity of the seawater, the spring water masses on the Bering Sea shelf were classified as the Alaskan Coast Water, Bering Sea Shelf Water, Anadyr Water, Spring Mixed Layer Water, Remnant Winter Water, and Winter Water, each of which had varying chlorophyll a concentrations. Among them, the highest chlorophyll a concentration occurred in the nutrient-rich Anadyr Water ((7.57±6.16) mg/m3 in spring). The spectrum-dependent diffuse attenuation coefficient (Kd(λ)) of the water column for downwelling irradiance was also calculated, exhibiting a decrease at 412–555 nm and then an increase within the range of 0.17–0.48 m–1 in spring. Furthermore, a strong correlation between the chlorophyll a concentration and the attenuation coefficient was found at visible wavelengths on the Bering Sea shelf. Spatially, the chlorophyll a concentration was higher on the northern shelf ((5.18±3.78) mg/m3) than on the southern shelf ((3.64±2.51) mg/m3), which was consistent with the distribution of the attenuation coefficient. Seasonally, the consumption of nutrients by blooms resulted in minimum chlorophyll a concentration ((0.78±0.51) mg/m3) and attenuation coefficient values in summer. In terms of the vertical structure, both the attenuation coefficient and the chlorophyll a concentration tended to reach maximum values at the same depth, and the depth of the maximum values increased as the surface temperature increased in summer. Moreover, an empirical model was fitted with a power function based on the correlation between the chlorophyll a concentration and the attenuation coefficient at 412–555 nm. In addition, a spectral model was constructed according to the relationship between the attenuation coefficients at 490 nm and at other wavelengths, which provides a method for estimating the bio-optical properties of the Bering Sea shelf. 相似文献
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Giorgio Budillon Pasquale Castagno Stefano AlianiGiancarlo Spezie Laurie Padman 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(10):1002-1018
We use hydrological and current meter data collected in the Ross Sea, Antarctica between 1995 and 2006 to describe the spatial and temporal variability of water masses involved in the production of Antarctic Bottom Water (AABW). Data were collected in two regions of known outflows of dense shelf water in this region; the Drygalski Trough (DT) and the Glomar-Challenger Trough (GCT). Dense shelf water just inshore of the shelf break is dominated by High Salinity Shelf Water (HSSW) in the DT and Ice Shelf Water (ISW) in the GCT. The HSSW in the northern DT freshened by ∼0.06 in 11 y, while the ISW in the northern GCT freshened by ∼0.04 in 8 y and warmed by ∼0.04 °C in 11 y, dominated by a rapid warming during austral summer 2001/02. The Antarctic Slope Front separating the warm Circumpolar Deep Water (CDW) from the shelf waters is more stable near GCT than near DT, with CDW and mixing products being found on the outer DT shelf but not on the outer GCT shelf. The different source waters and mixing processes at the two sites lead to production of AABW with different thermohaline characteristics in the central and western Ross Sea. Multi-year time series of hydrography and currents at long-term moorings within 100 km of the shelf break in both troughs confirm the interannual signals in the dense shelf water and reveal the seasonal cycle of water mass properties. Near the DT the HSSW salinities experienced maxima in March/April and minima in September/October. The ISW in the GCT is warmest in March/April and coolest between August and October. Mooring data also demonstrate significant high-frequency variability associated with tides and other processes. Wavelet analysis of near-bottom moored sensors sampling the dense water cascade over the continental slope west of the GCT shows intermittent energetic pulses of cold, dense water with periods from ∼32 h to ∼5 days. 相似文献
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东海陆架表层水温年际变化时空特征分析 总被引：2，自引：2，他引：0
结合东海沿岸嵊山(北)和厦门(南)站1960—2001年海表温度(SST)监测数据与东中国海1982—2011年AVHRR水温资料,讨论了台站监测的空间代表范围,分析了东海陆架SST年际变化的时空特征。结果表明,嵊山和厦门站SST变化分别代表内陆架和台湾海峡。东海陆架52年来SST总体呈升温趋势,冬季最为显著;内陆架的升幅远大于台湾海峡。内陆架水温冬季分别在1977年和1995年发生两次跃升,共升温2.34℃;春、夏、秋季均在1994年发生冷暖转折,分别升高1.19℃、1.43℃和1.16℃。台湾海峡水温冬季在1989年跃升0.91℃,夏季在1987年跃升0.38℃,春、秋季则在1996—1997年间分别升温0.80℃和0.58℃。全年水温变化最大处在长江口附近内陆架海区,可能的主导因素是低盐水与外海水混合:随季风、降水、径流变化的沿岸流、长江冲淡水和台湾暖流给该区域带来不同水团,使得热量向下层输运减少,从而导致东海内陆架升温快于其它海区。 相似文献
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Distribution of Pacific-origin water in the region of the Chukchi Plateau in the Arctic Ocean in the summer of 2003 总被引：6，自引：1，他引：6
1Introduction Besidestheprecipitationandriverdischarges,the watersinthePacificOceanandtheAtlanticOceanare thesourcesoftheArcticOceanwater.TheAtlantic waterenterstheArcticOceanviatheFramStraitand theBarentsSea.Foritsdenserfeatureduetohigh salinity,mostofitsinkstothenorthofSvaldbardand circulatesinallthedeepbasinsintheArcticOcean, formingthedeepandbottomwatersoftheArcticO- cean(Aagaardetal.,1985;Rudelsetal.,1999).The BeringStraitistheonlychannelforthePacificwater toflowintotheArcticOce… 相似文献
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Micro- and macronutrients in the southeastern Bering Sea: Insight into iron-replete and iron-depleted regimes 总被引：2，自引：0，他引：2
Ana M. Aguilar-Islas Matthew P. Hurst Bettina Sohst Maeve C. Lohan 《Progress in Oceanography》2007,73(2):99-126
Surface transects and vertical profiles of macronutrients, dissolved iron (D-Fe), and dissolved manganese (D-Mn) were investigated during August 2003 in the southeastern Bering Sea. We observed iron-limited, HNLC surface waters in the deep basin of the Bering Sea (15-20 μmol/kg nitrate, ∼0.07 nmol/kg D-Fe, and ?1.0 nmol/kg D-Mn); nitrate-limited, iron-replete surface waters over the shelf (<0.1 μmol/kg nitrate, 0.5-4 nmol/kg D-Fe, and 2-33 nmol/kg D-Mn); and high biomass at the shelf break (“Green Belt”), where diatoms appeared to have been stressed by low D-Fe concentrations (<0.3 nmol/kg). Sources of nitrate and iron to the Green Belt were investigated. A mixture of Aleutian North Slope Current water (with elevated, but non-sufficient iron concentrations relative to its high nitrate concentrations) and surface waters from the vicinity of the Bering Canyon (with lower nitrate concentrations, but similar dissolved iron concentrations) was carried along the shelf break by the Bering Slope Current. This water mixture provided macro- and micronutrients at the southern end of the shelf break. The oceanic domain supplied additional macronutrients to Green Belt waters, while the bottom layer of the outer shelf domain supplied additional macro- and micronutrients through enhanced vertical mixing at the shelf break. Surface waters near the Pribilof Islands, where the highest surface D-Fe concentrations were observed (∼5-6 nmol/kg), represent a potential source of additional iron to Green Belt waters. During summer, the subsurface water of the middle shelf domain is a potential source of nitrate to the nitrate depleted waters of the shelf. In this subsurface cool pool, we observed evidence of substantial denitrification with lower than expected nitrate concentrations. 相似文献
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Thomas M. Church Christopher N.K. Mooers Arthur D. Voorhis 《Estuarine, Coastal and Shelf Science》1984,19(4):393-411
A synoptic oceanographic study was conducted in August 1978 at the Middle Atlantic shelfbreak along the shelf-slope front and over the Wilmington Canyon. Four masses (surface, cold pool, shelf, and slope waters) were identified from nutrients and hydrographic variables. Also identified were two pycnocline mixing regimes; one between cold pool and slope waters across the inverted thermocline at the bottom of the cold bool protruding off the shelf, and the other directly across the summer thermocline between slope and shelf waters seaward of the cold pool. These two distinct mixing regimes appear to provide some of the common means for water exchange across the shelf-slope front. The associated mixing may be promoted by the circulation and mixing anomalies induced over canyon topographies. Physical data suggested a cyclonic flow pattern over the Wilmington Canyon, with warm slope water moving up its axis and cold pool water moving off its southwest flank. The above water masses were best identified chemically on the basis of oxygen saturation due to the high apparent photosynthesis at the shelf-slope front. This high primary productivity at the front seems linked to the cold pool and its nutrient supplies. 相似文献