共查询到20条相似文献，搜索用时 62 毫秒
1.
2.
234 Th示踪法测定北太平洋西北海域冬季真光层中颗粒态有机碳输出通量 总被引：1，自引：0，他引：1
讨论了1997年冬季在北太平洋西北海域7个站位的表层至200m水深水柱中溶解及颗粒态234Th,颗粒态有机碳(POC)、氮(PON)及叶绿素a浓度的垂直分布剖面.溶解态、颗粒态及总的234Th的放射性在真光层中显著低于母体238U的放射性,总的234Th放射性在水深大于100m时趋于平衡.利用234Th-238U在海洋表层海水中的放射性不平衡推导出了北太平洋西北海域冬季真光层海水中234Th的平均停留时间和输出通量以及颗粒态有机碳和有机氮的输出通量.在亚北极环流区溶解态234Th的停留时间为40~50d,而在黑潮-亲潮共同影响区为20d左右.颗粒态有机碳和有机氮从真光层的输出通量范围分别为3.8~8.2和0.50~0.98mmol/(m2·d),西部海区高于东部海区,南部海区高于北部海区.在黑潮-亲潮共同影响区较高的颗粒态有机碳输出通量表明光照量及陆源营养盐物质的提供是两个决定生产力的主要因素.叶绿素a的水深分布和POC/PON的值同Redfield的比值的一致性表明这个海区的冬季颗粒物主要由浮游植物构成.北太平洋西北海域在冬季的颗粒有机碳输出通量可高于世界大洋一些海区春、夏季的颗粒有机碳输出通量. 相似文献
3.
南沙海域基于234Th-238U不平衡的颗粒态有机碳输出通量研究 总被引：1，自引：0，他引：1
利用234Th-238U不平衡方法研究南沙群岛海域春季真光层颗粒动力学性质,测定了4个站位水柱中颗粒态有机碳(POC)、溶解态及颗粒态234Th和238U的含量,讨论了各站位水柱中234Th/238U)A.R.的垂直分布.运用稳态箱式模型计算各站位不同水层中溶解态234Th相对于清除至颗粒物的平均停留时间和颗粒态234Th相对于迁出作用的平均停留时间.结合POC/234ThP比值,用两种方法估算出各站位的颗粒态有机碳输出通量分别为8.51-34.94和13.28-50.06mmol·(m2·d)-1.两种方法结果一致,说明234Th是表征POC循环的良好示踪剂. 相似文献
4.
南极普里兹湾外海沉降颗粒物通量、组成变化及其与罗斯海对比研究 总被引：1，自引：2，他引：1
在南极普里兹湾外开阔海域布放时间系列沉积物捕获器,研究沉降颗粒物中生源组分(生物硅、有机质、碳酸钙)通量、组成、来源及元素的摩尔比值的生物地球化学意义,结果表明Ⅲ-1+站在1000m处颗粒物总通量的变化为13.00~334.59mg/(d·m2),颗粒物中以生物硅为主,占总通量的80%以上;各组分通量呈现明显的季节性变化.结合罗斯海沉降颗粒物通量和元素的摩尔比值的对比研究表明,研究海域1000m深的沉降颗粒物中生物硅与有机碳元素摩尔比值、无机碳与有机碳的元素摩尔比值较高,表明研究海域生物硅与有机碳生物地球化学循环过程是非耦合的,生物活动有效地将CO2由表层水中移出. 相似文献
5.
利用234Th－238U不平衡研究南海东北部海域3个站位上层水体中的颗粒动力学性质，测定了水往中溶解态及颗粒态234Th的比活度，具体讨论各相中234Th／238U）AR（放射性活度比）比值的垂直分布情况及其与水化学要素间的关系。运用稿态箱式模型计算出各站位不同水层中溶解态234Th相对于清除至颗粒物的平均停留时间和颗粒态234Th相对于迁出作用的停留时间。由模型得出的参数表明3个站位的真光层具有两种不同的层化图像，这一情形与我们在南沙群岛海域得到的结果相一致。结合POC／PTh比值，估算出3个站位从真光层输出的颗粒有机碳（POC）通量分别为4.025.0和5．4mmolC·m－3－d-1。文中进一步讨论了234Th与POC两者停留时间的关系。 相似文献
6.
本文首次报道用沉物捕捉器研究南沙群岛珊瑚礁泻湖沉降颗粒物中主要元素垂直通量、垂直转移形态,与表层海水温度的关系。 相似文献
7.
南海北部生源要素的垂直输运和保存及其与东太平洋的对比研究 总被引：1，自引：0，他引：1
通过对南海北部夏、冬两个季节的生源要素垂直输运剖面和时间系列沉积物捕获器的测量资料进行综合研究表明:南海北部颗粒物质主要是由钙质生物壳、生物硅、海洋浮游生物的有机质以及岩源物质组成,颗粒物质通量在1 000 m处大约为90.0 mg/(m2·d);研究还表明颗粒有机碳在进入沉积物保存之前被大量溶解,南海北部来自底层顺坡搬运的有机碳远大于垂直沉降;与开阔大洋(东太平洋海域)的对比研究表明,边缘海对于季节的变化更加敏感,而东太平洋调查区位于热带赤道高生产力带,生物作用十分明显,其海洋生物呼吸和物质转移同样也较活跃. 相似文献
8.
黄海夏季水域沉降颗粒物垂直通量的研究 总被引：12，自引：1，他引：12
20 0 2年 8月 ,沿穿过黄海冷水团的青岛至济州岛断面 ,在 4个站位放置沉积物捕获器采集沉降颗粒物。镜检发现无机颗粒物、生物粪球以及混杂聚合体是本断面沉降颗粒物主要类型。测定结果显示沉降颗粒物中的颗粒有机碳 (POC)、颗粒有机氮 (PON)、颗粒碳 (PC)、颗粒氮 (PN)和颗粒磷 (PP)的百分含量均呈现从表层到底层逐渐下降的趋势。采用两个改进的模型对底层颗粒物再悬浮比率进行了计算 ,显示黄海海域夏季底层沉降颗粒物再悬浮比率为 90 %— 96%,表明底层沉降颗粒物主要来源于沉积物的再悬浮。两模型所得结果一致 ,证明用温跃层底部颗粒物沉降通量代表水体中颗粒物净沉降通量的假设是合理的。水体中颗粒物、POC及PON的净沉降通量 (±SE)分别为 ( 1 2 65± 3 5 5 )g/(m2 ·d)、( 0 2 9± 0 0 4 )g/(m2 ·d)和( 0 0 6± 0 0 1 )g/(m2 ·d)。 相似文献
9.
10.
桑沟湾夏、秋季悬浮颗粒物的沉降通量及再悬浮的影响 总被引：1，自引：0，他引：1
应用锚式悬挂沉积物捕捉器法,研究了我国北方重要海水养殖区域桑沟湾悬浮颗粒物沉降通量的分布特征,并通过金属Al标记法,同步测定了沉降颗粒物再悬浮比率。结果表明,桑沟湾的底层悬浮颗粒物(SPM)、颗粒有机碳(POC)、颗粒态总氮(PTN)和颗粒态总磷(PTP)平均表观沉降通量分别为1 511.4g/(m2·d)、20.01g/(m2·d)、1.497g/(m2·d)和0.474g/(m2·d),显著高于我国其他近岸海域,但底层沉降颗粒物再悬浮比率平均值高达92.8%,认为在养殖内湾,受再悬浮程度的影响,测得的底层表观沉降通量是中层的2.7倍,秋季明显大于夏季,海带和扇贝养殖区大于牡蛎养殖区。经再悬浮比率校正后的净沉降通量,仍存在着显著的空间和季节变化,但受控因素发生了根本转变;这主要表现为净沉降颗粒物质主要源于生物代谢活动强烈中上层水体,贝类的排泄作用使牡蛎和扇贝养殖区的净沉降通量显著大于海带养殖区,养殖贝类个体增大、排泄量增加使秋季净沉降通量高于夏季。在我国近岸海域,再悬浮作用的影响,会对该区域悬浮颗粒物沉降通量的估算带来巨大误差,因此该作用不容忽视。 相似文献
11.
This paper analyses the global tendency of the sea level rise (SLR) and its long term influence on the sea level upstream drainage cascade based on the example of the level’s variation in the Vistula Lagoon of the Baltic Sea compared to the other lagoons and coastal regions of the southeastern part of the Baltic Sea. A steady positive trend in the water level variations was revealed; its magnitude varies significantly depending on the time period. In general, during the 100–150 year period, the rate of the SLR in the lagoons and coastal areas of the Baltic Sea (1.7–1.8 mm per year) is close to the SLR rate in the World Ocean. In the second half of the 20th century, the increased rate of the SLR in the lagoons and marine areas became stronger (up to 3.6 mm per year in the Vistula Lagoon and in 1959–2006 in the sea and exceeded the rate of global ocean SLR). It dramatically increased at the end of the last century both in the lagoons and in the sea (up to 10.0–15.0 mm per year). This is the response not only to the global climate warming but it is likely that it is also a response to the changes of the climate driving forces that influence the regimes of the local wind and precipitation in the catchment. 相似文献
12.
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
13.
1 古新-下渐新统含油气层系 古新-始新统母岩形成于滨海和湖泊沉积环境中，并在大量冲积源的参与之下，促进了含分散有机质混合类型砂-黏土质陆源岩层的堆积。在中国东北诸盆地中，含工业油气的白垩-早第三纪建造形成于开阔的浅水和深水湖泊环境中。与中国的盆地类似，在下第三系下部 相似文献
14.
Izvestiya, Atmospheric and Oceanic Physics - The Great Andaman–Sumatra earthquake (GASE) on December 26, 2004, with magnitude Mw of 9.2, occurred in the Indian Ocean near the northwestern... 相似文献
15.
Data on the contents and compositions of the hydrocarbons (HCs)—aliphatic (AHCs) and polycyclic aromatic (PAHs)—are provided
in comparison with the contents of the total organic carbon (Corg), the lipids in the particulates, and the Corg in bottom sediments. Particular attention has been paid to the distribution of the HCs in the water area of the Kravtsov
oil field. It has been established that the concentrations of AHCs in the water are governed by the content of particulates,
and the elevated AHC concentrations are confined to the coastal areas. In the water area of platform D-6, the sandy bottom
sediments were notable for the great variability of the HC concentrations, both laterally and from year to year. In the summer
of 2010, the content of AHCs averaged 40 μg/g (19% in the Corg), and that of PAHs, 23 ng/g. Natural seepage from the sediment mass is considered to be a source of HCs along with oil contamination. 相似文献
16.
Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east 总被引：2，自引：0，他引：2
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry
dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly
goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with
the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then
passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state. 相似文献
17.
Causes of the bottom hypoxia in the eastern part of the Gulf of Finland in the baltic sea 总被引：1，自引：0，他引：1
A. A. Maximov 《Oceanology》2006,46(2):185-191
The data on the bottom concentrations of dissolved oxygen in the eastern part of the Gulf of Finland obtained in 1923–1939 and in 1962–1989 were analyzed. No statistically reliable differences were found between the two periods studied. It was found that, during the 20th century, the fluctuations in the oxygen concentration were caused by the interannual variability of the winter severity and water salinity. A strong oxygen deficit in the summer was recorded after cold winters, when early freezing suppressed the vertical mixing, and/or in the years of a significant inflow of salt waters from the Baltic Sea with low oxygen contents. It is likely that the long-term dynamics of the oxygen concentration near the bottom in the open parts of the bay is determined by the large-scale variability of the hydrometeorological parameters. 相似文献
18.
The role of the small-size (SF; 0.1–0.5 mm) and large-size (LF; 0.5–20.0 mm) fractions in the biomass and abundance of mesozooplankton
(0.1–20.0 mm) was assessed using the database of samples obtained during the cruises of RV Akvanavt in the northeastern Black Sea in November 2000 and October 2006. The mesozooplankton was collected by means of Juday nets
(37/50, filtering gauze 160 μm) and Niskin bottles in two areas: (1) the shelf and continental slope (30–1480 m depth) and
(2) the deep sea (depths of more than 1500 m). The plankton net was considerably less effective in collecting the SF of the
mesozooplankton (by a factor of 30–36) than the Niskin bottles. When comparing the SF and LF, we estimated the abundance and
biomass of the SF in the samples obtained with the Niskin bottles. The abundance of the SF in the deep-sea area was 2.5 times
lower compared to the shelf and continental slope, and the LF abundance was 5.0 times lower in the same way. The abundance
of the SF constituted 88% of the total mesozooplankton on the shelf and continental slope, and 78% in the deep-sea area. The
biomass of the SF was higher as well on the shelf and continental slope. Meroplankton played a significant role in the SF
zooplankton abundance (0.5 × 103 + 0.16 ind. m−3) in this area. The SF grazing impact was 10% of the total mesozooplankton grazing on the shelf and continental slope, and
17% in the deepsea area. Appendicularia and nauplii of copepods had the greatest contribution to the mesozooplankton grazing
among the SF group. 相似文献
19.
20.
Using the data of long-term simultaneous optical, biological, and hydrological observations (1980–1993), particular features of the horizontal distribution of the transparency and the total particulate matter content and the contents of its organic components (organic carbon and nitrogen and chlorophyll a) and their variability in the surface water layer (0–5m) over the northwestern shelf and the adjacent abyssal part of the Black Sea in the autumn season are considered. The detritus/phytoplankton ratio in the particulate organic matter and their relative contents in the total particulate matter are calculated. The distributions of the transparency and particulate matter content were found to be in good agreement and both depend on the water dynamics. It was established that, during the period of the abrupt growth in the Black Sea water turbidity (in the early 1990s), a significant decrease in the transparency and an increase in the particulate matter content caused by the production-destruction processes were observed only in the central and southern regions of the sea. 相似文献