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1.
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   

2.
Variability of the Kuroshio in the East China Sea in 1992   总被引：3，自引：3，他引：0  
INTRODUCTIONMostofpreviousstudiesshowthatthedynamicmethodswereoftenusedtocomputethevelocityandVToftheKuroshiointheEastChinaSea(Guan,1988;Nishizawaetal.,1982;SunandKaneko,1993).Duringrecentyearsdifferentkindsofinversemethodshavebeentriedby*ThisprojectwassupportedbytheNationalNaturalScienceFoundationofChinaundercontractNo.49776287.1.Secondinstituteofoceanography,StateOceanicAdministration,Hangzhou310012,ChinaYuanetul(1988,1991,1992a,1992b,1993,1994,1995).Theircalculatedresultsshowt…  相似文献   

3.
利用9层15波全球大气环流谱模式研究了太平洋海温异常对南海西南季风建立早晚的影响作用.结果表明:西-中太平洋海温异常数值试验结果最能反映出南海西南季风爆发早、晚年4～5月份大气环流的差异特征.数值试验结果显示:西太平洋海温正(负)异常可导致西太平洋副高减弱(加强);中太平洋海温正(负)异常主要使得中太平洋上空的洋中槽减弱(加深);东太平洋海温正(负)异常可造成东太平洋赤道两侧高层环流产生反气旋性(气旋性)变化,孟加拉湾-南海-西太平洋热带地区出现东风(西风)异常,西太副高加强(减弱).可见西太平洋海温异常和东太平洋海温异常都可以对副高强弱变化产生明显影响,从而对南海西南季风建立早晚产生影响,只不过西太平洋海温异常的影响作用更为显著.西太平洋正(负)海温异常与中太平洋负(正)海温异常经常是同时出现的,其激发出的与向东传的Kelvin波和向西传的行星波相联系的环流异常为南海季风建立早(晚)提供有利的条件,因而这一海温分布型是影响南海西南季风建立早晚的重要影响因子.  相似文献   

4.
The results of ground-based measurements of the total content (TC) of hydrogen fluoride in the atmosphere in Peterhof near St. Petersburg for one year (from April 2009 through April 2010) using a Bruker IFS125 Fourier spectrometer with a high spectral resolution (0.005 cm?1) are presented. The well-known computer code SFIT2 (Zephyr-2) was used for the radiation data inversion. Random measurement errors were 1–5% and the systematic error was 5–10%. The seasonal trend of the HF TC in Peterhof is characterized by a minimum in summer and a maximum in winter through early spring and is very close to the seasonal HF TC trend obtained at the Harestua Network for the Detection of Atmospheric Composition Change (NDACC) station located at about the same latitude. A comparison of the St. Petersburg State University (SPbSU) ground-based measurements with the data of satellite HF TC measurements (with an ACE-FTS instrument) showed a good quantitative agreement of the results for the entire period of observations. According to our ground-based measurements and the satellite measurements with the ACE-FTS instrument, the mean values of the HF TC and its rms variations during the period under investigation are 1.77 × 1015 and 1.80 × 1015 cm?2 (difference 1.5%) and 21 and 18%, respectively.  相似文献   

5.
Anoxia and hypoxia have been widely observed in estuarine and coastal regions over the past few decades; however, few reports have focused on the East China Sea (ECS). In June and August 2003, two cruises sampled at stations covering almost the entire shelf of the ECS to examine hypoxic events and their potential causes. In August, DO concentrations <2-3 mg l(-1) covered an area estimated at greater than 12,000 km(2) (or 432 km(3) volume). In contrast, water column DO concentrations exceeded 4 mg l(-1) throughout most of the shelf region. A sharp density gradient was observed under the mixed layer in August, restricting vertical re-aeration across this strong pycnocline. Oxygen depletion events, such as that described here for the ECS shelf, are fueled by decomposition of newly produced marine and river-borne biogenic substances (as well as older residual organic matter) deposited to the bottom waters.  相似文献   

6.
本文分析该海域约７０个测站的温、盐资料，获得以下结果：（１）夏季在对马暖流的源区，于１０～７５ｍ水层内，其流路成一明显的分界线，左（西）侧温、盐度较低，右（东）侧温、盐度较高。（２）夏季对马暖流源区存在着三种海水：高温、高盐水，高温、低盐水和高温、次高盐水。（３）夏季朝鲜海峡地区，东水道的温、盐度高于西水道温、盐度。（４）１９８７年，东海黑潮区、长江口、杭州湾外及东海酉南部海域，夏季的表层盖度，皆比１９８９年同季、同一海域的盐度偏高；而对马暖流“东海段”却出现相反的低盐现象。其原因之一，１９８７年冲淡水势力极强，几乎盘踞了对马暖流源区的大部分海域，使源区盐度下降，并随对马暖流北上输送的缘故。其中：（１）和（４）两点认识系首次提出。  相似文献   

7.
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   

8.
本文利用美国NCEP/NCAR逐月的再分析资料、HadISST海温、中国160台站气温和反映渤海冰情轻重的渤海冰情等级资料,研究了前秋巴伦支海海温异常对后期渤海冰情和东亚冬季风的影响,并对相关的物理过程进行分析。结果表明,前秋巴伦支海关键区海温与该区域海冰密集度呈显著的负相关,且具有较好的持续性,通过调节随后冬季向大气释放的热通量,引起后期环流变化。偏高(偏低)年冬季亚洲纬向环流偏弱(偏强),东亚大槽加深(减弱),东亚冬季风加强(减弱),我国东北、华北及西北地区地区显著偏冷(偏暖),这与冬季渤海海冰异常的强度和范围都偏大(小)及与之相联系的环流异常相一致。进一步的分析揭示了联系上游关键区海温变化与后期东亚地区气候异常的重要途径,前秋巴伦支海海温偏高会导致200 hPa高度场形成一个自西向东的波列形式,在东亚局地Hadley环流异常的作用下,加强了我国北方地区地表的北风异常。因此,前秋巴伦支海海温异常可以作为冬季渤海冰情的预报因子。  相似文献   

9.
Massive mucilage events occur in the Northern Adriatic Sea presumably by cytoplasmic excretions from deteriorated diatoms. During three such events in the summer of 1991, 1997 and 1998 the presence of reduced sulfur species (RSS) was determined in samples of macroaggregate using electrochemical methods (in-phase alternating current (AC) and linear sweep voltammetry). The detected levels of sulfur, expressed as equivalent to sulfide concentrations, were about 200 nM. In the same mucilage samples, concentrations of organic matter were determined in the range from 60 to 600 mg/l of total organic carbon (TOC). The physico-chemical properties of organic matter in the macroaggregates correspond to those of polysaccharides of very high molecular mass. Scanning confocal laser microscopy (SCLM) and fluorescent molecular probes for sugars (the lectins concanvaline A (Con-A)) showed the transformation of polysaccharide polymer structure resulting in the formation of very stable filaments and layers after the treatment of mucilage samples with sodium sulfide. Commercial polysaccharides of bacterial and algal origin (xanthan, carrageenans types I and II, dextran-T-500) have been used to simulate macroaggregate formation under laboratory conditions after treatment with sodium sulfide. Raman spectroscopy indicated that for all model polysaccharides used, sulfide interaction occurred, as evidenced by visible change of the O–H stretching region in the vibration spectra of the water molecules.Our data suggest that the aggregated polysaccharides from the Adriatic Sea are: (1) structurally affected by addition of sulfide as was the case for most of the model polysaccharides, and (2) the stabilizing effect of sulfide on the aggregated polysaccharides is due to the formation of sulfur-organic compounds.  相似文献   

10.
应用Argo资料分析西北太平洋冬、夏季水团   总被引：1，自引：0，他引：1  
应用Argo剖面浮标观测的温、盐度资料,分析了西北太平洋海域冬、夏季的温、盐度分布、水团结构及其分布。首先采用T-S点聚图法分析了该海域水团分布的基本情况,由点聚分析结果可知,该海域至少存在6种以上水团;再用模糊聚类软化法对水团作进一步划分,分别计算了该海域6至11类水团的F和△F值,结果表明,冬、夏季的△F值都以划分为8类时为最大,这与大洋水团的稳定性是一致的,因此,该海域冬、夏季水团以划分为8类最佳,它们分别是北太平洋热带表层水、北太平洋次表层水、北太平洋中层水、北太平洋副热带模态水、北太平洋深层水和赤道表层水,以及南太平洋次表层水和南太平洋中层水。  相似文献   

11.
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   

12.
锯缘青蟹卵黄发生期卵巢和肝胰腺脂类的变化   总被引：16，自引：0，他引：16  
锯缘青蟹2次卵巢发育时的卵黄发生旺期与卵黄发生初期相比,卵巢指数和卵巢脂肪含量(%卵巢干重或湿重)均显著增加,积累了大量的脂类,而这一时期的肝胰腺指数和肝胰腺脂肪含量均无显著变化,说明在卵黄发生时期,肝胰腺吸收的脂肪均及时转运到正在发育的卵巢.卵黄发生期,卵巢或肝胰腺磷脂/总脂的百分含量,均无显著变化,肝胰腺中游离脂肪酸逐步增加,甚至在卵黄发生后期超过甘油三酯的含量.卵黄发生阶段,无论肝胰腺或卵巢,其磷脂长链多不饱和脂肪酸显著高于中性脂,而饱和脂肪酸含量相对较低;肝胰腺脂类脂肪酸组成的最主要变化是中性脂的n3系列的长链多不饱和脂肪酸,尤其是C22:6n3显著降低.卵黄发生初期,肝胰腺磷脂与卵巢中性脂的脂肪酸组成(肝胰腺转运脂肪时,首先要将吸收或储存的脂类转换成磷脂,才能运出)无显著差异,但卵黄发生旺期,肝胰腺磷脂的长链多不饱和脂肪酸显著高于卵巢中性脂的含量.文中讨论了这些变化的原因.  相似文献   

13.
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   

14.
The Belgian MPA designation process started in 1999, a journey that was characterized by several conflicts related to the multi-level government system in Belgium and obstacles, e.g. the de-designation of the Special Area of Conservation (SAC) 'Vlakte van de Raan' in 2008. On the other hand a number of successful events could be noted as well, e.g. the designation of three Special Protection Areas (SPAs) in 2005 in front of the three marine harbors, and the extension of the SAC 'Trapegeer-Stroombank' (designated in 2005) to an area >30% of the BPNS surface in 2012 (now renamed to SAC 'Vlaamse Banken'). The most important aspects that contributed to the successful designation of these MPAs in the BPNS were (1) the appointment of a minister of the North Sea in 2003 (and 2011), who was dedicated and specifically mandated to coordinate all federal North Sea matters (thus excluding fisheries); (2) the growing awareness of the need for nature conservation through different EU Directives (e.g. Marine Strategy Framework Directive (MSFD)); and (3) the level of stakeholder and public involvement, especially focusing on transparency throughout the process.  相似文献   

15.
夏季珠江口水体中多环芳烃的分布、组成及来源   总被引：2，自引：0，他引：2  
利用1999年7月对珠江口海域的调查资料,对该区表层海水中优控多环芳烃的分布、组成及来源进行了分析和讨论,结果表明:(1)夏季珠江口海域表层海水中14种溶解态多环芳烃[苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、艹屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)艹北、茚并(1,2,3-cd)艹比]的质量浓度为63.8~171.7 ng/L,且沿着冲淡水流向呈降低趋势;(2)颗粒态中15种多环芳烃[萘、苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、艹屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)艹北、茚并(1,2,3-cd)艹比]的质量浓度为60.7~186.7 ng/L,其分布与水体载沙量及悬浮颗粒物的性质、粒径有关,具有从河口内向外海降低的分布特征;(3)多环芳烃组成和特征参数比值的分析表明,珠江口海域高温裂解来源的多环芳烃在伶仃洋海区输入最多,且主要为人类活动中煤燃烧排放的,而在香港岛周围海区的输入则相对较少,且主要为油燃烧排放的;(4)与法国塞纳河及长江口等河口相比,珠江三角洲海域水体中存在高菲含量排放源。  相似文献   

16.
In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and i  相似文献   

17.
1 IntroductionTheBeringStrait, with them aximum depth lessthan 60 m , isthe uniquepassagebetween the ArcticOcean and the North Pacific Ocean, and links twoshelfseas:theBeringSeainthesouthandtheChukchiSea in the north. The background flow field oftheBering…  相似文献   

18.
Using the 28°C isotherm to define the Western Pacific Warm Pool(WPWP), this study analyzes the seasonal variability of the WPWP thermohaline structure on the basis of the monthly-averaged sea temperature and salinity data from 1950 to 2011, and the dynamic and thermodynamic mechanisms based on the monthly-averaged wind,precipitation, net heat fluxes and current velocity data. A DT=–0.4°C is more suitable than other temperature criterion for determining the mixed layer(ML) and barrier layer(BL) over the WPWP using monthly-averaged temperature and salinity data. The WPWP has a particular thermohaline structure and can be vertically divided into three layers, i.e., the ML, BL, and deep layer(DL). The BL thickness(BLT) is the thickest, while the ML thickness(MLT) is the thinnest. The MLT has a similar seasonal variation to the DL thickness(DLT) and BLT.They are all thicker in spring and fall but thinner in summer. The temperatures of the ML and BL are both higher in spring and autumn but lower in winter and summer with an annual amplitude of 0.15°C, while the temperature of the DL is higher in May and lower in August. The averaged salinities at these three layers are all higher in March but lower in September, with annual ranges of 0.41–0.45. Zonal currents, i.e., the South Equatorial Current(SEC)and North Equatorial Counter Current(NECC), and winds may be the main dynamic factors driving the seasonal variability in the WPWP thermohaline structure, while precipitation and net heat fluxes are both important thermodynamic factors. Higher(lower) winds cause both the MLT and BLT to thicken(thin), a stronger(weaker)NECC induces MLT, BLT, and DLT to thin(thicken), and a stronger(weaker) SEC causes both the MLT and BLT to thicken(thin) and the DLT to thin(thicken). An increase(decrease) in the net heat fluxes causes the MLT and BLT to thicken(thin) but the DLT to thin(thicken), while a stronger(weaker) precipitation favors thinner(thicker)MLT but thicker(thinner) BLT and DLT. In addition, a stronger(weaker) NECC and SEC cause the temperature of the three layers to decrease(increase), while the seasonal variability in salinity at the ML, BL, and DL might be controlled by the subtropical cell(STC).  相似文献   

19.
On the basis of hydrographic data obtained in November 28 to December 27, 1998 cruise, the calculation of the circulation in the South China Sea (SCS) is made by using the P-vector method, in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of winter circulation in the SCS, the diagnostic model (Yuan et al., 1982; Yuan and Su, 1992) is used to simulate numerically the winter circulation in the SCS. The following results have been obtained. (1) The main characteristics of the circulation systems in the central SCS are as follows: A coastal southward jet in winter is present at the western boundary near the coast of Vietnam; there is a stronger cyclonic circulation with a larger horizontal scale east of this coastal southward jet and west of 114°E; there is a weaker anti-cyclonic circulation in the central part of eastern SCS; there is a stronger and northeastward flow opposing the northeasterly monsoon between above a stronger cyclonic c  相似文献   

20.
Variability of the Kuroshio in the East China Sea in 1993 and 1994   总被引：11，自引：1，他引：10  
INTRODUCTIONTherearemanyworksabouttheKuroshioVTintheEastChinaSeaanditsseasonalvariabil*ThisprojectwassupportedbytheNationalNaturalScienceFoundationofChinaundercontractNo.49776287.1.SecondinstituteofOceanography,StateOceanicAdministration,Hangzhou310012,Chinaity(Guan,1988;Nishizawaetal.,1982;SunandKaneko,1993;Yuanetal.,1990,1993,1994,1995).Thecomputationmethodusedtobethedynamicmethod(Guan,1988;Nishizawaetal.,1982;SunandKaneko,1993),butrecentlytheinverseandthemodifiedinversemetho…  相似文献   

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