北黄海冷水团季节变化特征分析

基于2006至2007年“908”项目执行期间春夏秋冬共四个航次的CTD温盐数据,针对四个季节底层大面及大连一成山头断面温度和盐度的分布特征,分析了北黄海冷水团的季节变化,初步探讨了其消长过程,并与历史资料相比较,发现了关于北黄海冷水团的新问题。研究表明：夏季,北黄海冷水团温度和盐度与历史资料相比,低温中心位置存在东偏,但低温中心温度和盐度变化不大。春季,32．8psu高盐水舌主轴位置较冬季偏西约75km,123．5°E以东的原冬季盐度高值区的范围向北延伸的势力大减,退化为较弱的小高盐水舌冬。冬季,北黄海冷水团已经消失,黄海暖流呈舌状向北延伸。秋季,减弱的北黄海冷水团存在两个中心温度约9℃的低温中心。     

北黄海冷水团季节变化特征分析

利用2006—2007年春、夏、秋、冬4个航次的CTD数据,对北黄海冷水团的季节变化及其消长过程进行了分析.结果显示:春季,冷水团特征开始出现,6℃冷水占据了调查区域的1/3,冷水团中心的盐度值大于32 psu.成山头以东的高盐水舌主轴从冬季的124°E西移至123.3°E处;夏季,北黄海冷水团特征最为明显,核心温度约6℃,盐度高于32 psu,盘踞在50 m等深线以深的深槽中,温、盐呈现明显的双峰结构.与前人的结果相比,本文低温中心的位置偏东;秋季,北黄海冷水团强度减弱,但仍存在2个低温中心,并且高盐中心位于38.5°N,122.5°E附近;在垂直方向上,冷水团与上层水之间以温跃层为分界:温跃层春季时形成,位于20～30m;夏季达到最强,跃层在10～20m;秋季减弱,跃层深度降至30～40m;至冬季温跃层完全消失.     

夏季北黄海冷水团多年变化特性分析

本文根据横贯北黄海冷水团的大连一成山角断的４２年观测资料，采用“相似系数”方法分析了北黄海冷水团的分布范围、低温中心位置、厚度、相对体积、温、盐等特征等多年变化特征。根据诸特征的标准离差，将这４２年北黄海冷水团划分为强、弱和平年三种情况。     

北黄海冷水团温、盐多年变化特征及影响因素

基于1976~1999年的海洋调查资料,主要研究了北黄海冷水团温、盐的多年变化特征,并结合该时间区间内黄河径流量及海洋站的气温、风速等资料探讨影响北黄海冷水团温、盐变化的因素.结果表明,北黄海冷水团在这24 a间温度稍呈上升趋势(0.005℃/a),盐度升降趋势则不明显.其温度主要受冬季气温影响,黑潮现象会使温度变异.盐度主要受黄海暖流、渤海热通量、海域冬季大风的共同作用;黄河径流量可能不是影响北黄海冷水团盐度变化的主要因素,但其径流量的大幅度变化也会影响北黄海冷水团的盐度变化趋势.     

夏季北黄海冷水团多年变化特征分析

本文根据横贯北黄海冷水团的大连—成山角断面的４２年观测资料，采用“相似系数”方法分析了北黄海冷水团的分布范围、低温中心位置、厚度、相对体积、温、盐特征等的多年变化特征。根据诸特征的标准离差，将这４２年北黄海冷水团划分为强、弱和平年三种情况     

北黄海夏季冷水团营养盐贡献的估算

根据2006年北黄海夏季航次调查资料,初步估算夏季冷水团及整个调查海区的水体体积,进而分别计算两者的营养盐总量,并在此基础上估算夏季冷水团区营养盐对调查海域的贡献.结果表明冷水团作为营养盐的高值区,以仅占调查海区总体积23.7％的体积分数,达到了对DIN、PO4-P和SiO3-Si分别为46.3％、63.9％和32.1％的贡献率,尤其是PO4-P的贡献量,更是达到海区总量的一半以上,充分体现出其营养盐贮库,特别是PO4-P贮库的特性.在水体层化减弱、消失的季节,冷水团对整个水体的营养盐是极大的补充.     

黄海冷水团的变化特征

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‰。     

北黄海底层冷水团的变化特征及其对外长山岛海区养殖扇贝死亡的影响

应用模糊聚类软划分算法，对北黄海底层水团进行了分析。根据分析的结果，可将该海区划分为三个水团：北黄海沿岸水，北黄海水团和北黄海冷水团，进而讨论了三个水团的月变化特征，北黄海冷水团的多年变化特征，以及冷水团温度变化与气温变化之间的关系。     

北白令海夏季冷水团的分布及其年际变化研究

利用1982-2008年间的高分辨率CTD数据,对夏季位于北白令海陆架底层的冷水团性质及其多年变化进行了研究.结果表明,依据该区域水体在温盐性质上的差异可以分为4类:陆架冷水团(BSW_C),白令海陆坡流水(BSCW),混合变性水(MW),陆架表层暖水(BSW_S).以-1℃,2℃和4℃温度等值线指示水团边界,清楚地将...     

黄海春季海雾的年际变化研究

利用黄海沿岸有代表性测站的常规观测资料和NCEP／NCAR资料，对黄海春季海雾年际变化进行了分析发现，雾多年份冬季环流减弱、低层流场向黄海为偏南向流入、中低层水汽充足、层结稳定；有雾时气温水温差在0．5—2．2℃范围内，地面风向以S-ESE为主。分析结果表明，在春季黄海雾形成过程中，高空环流提供了暖湿空气的输送条件，低层流场及地面风场的分布有利于来自西太平洋低纬地区的水汽向黄海海区输送；中低层水汽充沛，昙结稳定，水气温差在一定范围内有利于海雾的形成和维持。     

The temporal and spatial variability of the Yellow Sea Cold Water Mass in the southeastern Yellow Sea, 2009-2011

The Yellow Sea Cold Water Mass(YSCWM) is one of the important water mass in the Yellow Sea(YS).It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10 C and the salinity lower than 33.0.To understand the variability of the YSCWM,the hydrographic data obtained in April and August during 2009–2011 are analyzed in the southeastern Yellow Sea.In August 2011,relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area.Although the typhoon passed before the cruise,the salinity in the Yellow Sea central trough is much higher than the previous season.It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter.In April 2011,actually,warm and saline water(T >10 C,S >34) was observed in the deepest water depth of the southeastern area of the Yellow Sea.The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season.The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current.Therefore,it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.     

北黄海冷水团对獐子岛微微型浮游生物分布的影响

Picoplankton distribution around the Zhangzi Island(northern Yellow Sea)was investigated by monthly observation from July 2009 to June 2010.Three picoplankton populations were discriminated by flow cytometry,namely Synechococcus,picoeukaryotes and heterotrophic prokaryotes.In summer(from July to September),the edge of the northern Yellow Sea Cold Water Mass(NYSCWM)resulting from water column stratification was observed.In the NYSCWM,picoplankton(including Synechococcus,picoeukaryotes and heterotrophic prokaryotes)distributed synchronically with extremely high abundance in the thermocline(20 m)in July and August(especially in August),whereas in the bottom zone of the NYSCWM(below 30 m),picoplankton abundance was quite low.Synechococcus,picoeukaryotes and heterotrophic prokaryotes showed similar response to the NYSCWM,indicating they had similar regulating mechanism under the influence of NYSCWM.Whereas in the non-NYSCWM,Synechococcus,picoeukaryotes and heterotrophic prokaryotes exhibited different distribution patterns,suggesting they had different controlling mechanisms.Statistical analysis indicated that temperature,nutrients(NO3–and PO43–)and ciliate were important factors in regulating picoplankton distribution.The results in this study suggested that the physical event NYSCWM,had strong influence on picoplankton distribution around the Zhangzi Island in the northern Yellow Sea.     

黄海冷水团海域浮游植物磷胁迫的季节变动

The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass（YSCWM） is one of the most important physical features in the Yellow Sea. The characteristics of vertical profiles and seasonal variations of biogenic elements in the YSCWM may lead the variations of nutrient availability（e.g., phosphorus） and phosphorus stress of phytoplankton. In this study, the authors surveyed the seasonal variations of phytoplankton phosphorus stress with emphasis on the effect of the YSCWM during the four cruises in April and October 2006, March and August 2007. Using both bulk and single-cell alkaline phosphatase activity（APA） assays, this study evaluated phosphorus status of phytoplankton community, succession of phytoplankton community and ecophysiological responses of phytoplankton to phosphorus in the typical region of the YSCWM. With the occurrence of the YSCWM, especially the variations of concentration of dissolved inorganic phosphorus（DIP）, the results of bulk APA appeared corresponding seasonal variations. Along Transects A and B, the mean APA in August was the highest, and that in March was the lowest. According to the ELF-labeled assay＇s results, seasonal variations of the ELF-labeled percentages within dominant species indicated that diatoms were dominant in March, April and October, while dinoflagellates were dominant in August. During the four cruises, the ELF-labeled percentages of diatoms except Paralia sulcata showed that diatoms were not phosphorus deficient in April 2006 at all, but suffered from severe phosphorus stress in August 2007. In comparison, the ELF-labeled percentages of dinoflagellates were all above 50% during the four time series, which meant dinoflagellates such as Alexandrium and Scrippsiella, sustained perennial phosphorus stress.     

黄海冷水团的化学水文学特征

Based on the field data obtained during summer cruises in 2006, the overall perspective of chemical and hydrographic characteristics of the Yellow Sea Cold Water Mass(YSCWM) are discussed through the crossYSCWM transect profiles and horizontal distributions of hydrological and chemical variables, with emphasis on the differences between the northern Yellow Sea Cold Water Mass(NYSCWM) and the southern Yellow Sea Cold Water Mass(SYSCWM). The results show that YSCWM is characterized by low temperature(10°C) and dissolved oxygen(DO) concentration, high salinity(32.0) and nutrient concentrations. Compared to the SYSCWM, the NYSCWM possesses lower values of temperature, salinity and nutrient concentrations but higher values of DO.Also its smaller variation ranges of variables(except for temperature) demonstrate that NYSCWM is more uniform than that of SYSCWM. In addition, thermocline is more intensive in the SYSCWM than that of NYSCWM.Furthermore, DO and Chl a maxima appear at the depth of 30 m in the SYSCWM, while these phenomena are not obvious in the NYSCWM.     

Seasonal variability of the zooplankton community in the southwest of the Huanghai Sea (Yellow Sea) Cold Water Mass

Samples were collected with a plankton net in the four seasonal cruises during 2006-2007 to study the seasonal variability of the zooplankton community in the southwest part of Huanghai Sea Cold Water Mass (HSCWM, Yellow Sea Cold Water Mass). The spatial and temporal variations of zooplankton species composition, biomass, abundance and biodiversity were examined. A total of 122 zooplankton species and 30 pelagic larvae were identified in the four cruises. Calanus sinicus and Aidanosagitta crassa were the most dominant species, and Themisto gaudichaudi and Euphausia pacifica were widely distributed in the HSCWM area. The spatial patterns of non-gelatinous zooplankton (removing the high water content groups) were similar to those of the total zooplankton biomass in autumn, but different significantly in the other three seasons. The seasonal means of zooplankton biomass in spring and summer were much higher than that in autumn and winter. The total zooplankton abundance averaged 283.5 ind./m~3 in spring (highest), 192.5 ind./m~3 in summer, 165.5 ind./m~3 in autumn and 65.9 ind./m~3 in winter (lowest), and the non-gelatinous groups contributed the most total abundance. Correlation analysis suggests that the non-gelatinous zooplankton biomass and abundance had a significant positive correlation in the whole year, but the relationship was insignificant between the total zooplankton biomass and abundance in spring and summer. The diversity index H of zooplankton community averaged 1.88 in this study, which was somewhat higher than historical results. Relatively low diversity in summer was related to the high dominance of Calanus sinicus, probably due to the strongest effect of the HSCWM in this season.     

黄海冷水团上升流对叶绿素垂向分布的影响

利用黄海冷水团物理-生态耦合模式，对冷水团水域叶绿素垂向分布的季节变化进行了数值模拟研究。物理模式为冷水团热动力模型，生态模式主要考虑叶绿素，营养盐和食植浮游动物基本状态变量的耦合方程。研究结果表明，黄海冷水团上升流对叶绿素垂向分布的夏季上层结构具有显著影响。整个夏季，受上升流的影响，叶绿素垂向分布最大值的位置向海面抬升，量值增大，混合层叶绿素的平均浓度增加，与实测资料比较表明，考虑冷水团上升流的影响比不考虑上升流与实测结果符合要好。     

黄海冷水团海域微型异养鞭毛虫与细菌的弱耦合关系

A study was carried out to investigate the grazing pressure of heterotrophic nanoflagellates(HNF) on bacteria assemblages in the Yellow Sea Cold Water Mass(YSCWM) area in October, 2006. The results show that the HNF abundance ranges from 303 to 1 388 mL-1, with a mean of 884 mL-1. The HNF biomass is equivalent to 10.6%–115.6% of that of the bacteria. The maximum abundance of the HNF generally occurred in the upper 30 m water layer, with a vertical distribution pattern of surface layer abundance greater than middle layer abundance, then bottom layer abundance. The hydrological data show that the YSCWM is located in the northeastern part of the study area, typically 40 m beneath the surface. A weak correlation is found between the abundances of HNF and bacteria in both the YSCWM and its above water layer. One-way ANOVA analysis reveals that the abundance of HNF and bacteria differs between inside the YSCWM and in the above water mass. The ingestion rates of the HNF on bacteria was 8.02±3.43 h-1 in average. The grazing rate only represented 22.75%±6.91% of bacterial biomass or 6.55%+4.24% of bacterial production, implying that the HNF grazing was not the major factor contributing to the bacterial loss in the YSCWM areas.     

黄海冷水团大型鲑科鱼类养殖研究进展与展望

黄海中部洼地的深层存在一个巨大的夏季冷水团,面积约13万km^2,水质优良,可以利用现代海洋装备在此海域养殖大型鲑科鱼类。中国海洋大学黄海冷水团鲑鱼养殖团队研发了养殖工船,概念性地设计了海浪能驱动的5万m^3的全潜式钢构网箱"深蓝1号"和约17万m^3的养殖-能源-管理于一体的"深蓝2号"智能钢构网箱,成功地完成了黄海冷水团鲑科鱼类养殖技术路线的验证。为实现规模化安全生产,仍需对养殖容量与黄海冷水团变动、适养种类及其育种、养殖技术、病害防治、饲料研发、机械化生产与智能化管理等进行深入研究。     

黄海冷水团水域浮游植物群落粒级结构的季节变化

根据2006—2007年度4个季节航次的实测资料,分析了黄海冷水团水域浮游植物叶绿素及其粒级结构的时空分布特征及季节变化规律,结果表明,在研究海域30 m以浅叶绿素总量的平均含量从高到低的顺序为:春季的(1.01 mg/m3)、夏季的(0.81 mg/m3)、秋季(0.72 mg/m3)、冬季(0.68 mg/m3);在叶绿素浓度大于1 mg/m3和小于1 mg/m3的区域浮游植物粒级结构差异较大,在整个研究海域,粒径较小的微型和微微型浮游植物对总生物量的贡献始终占主导(65%),粒径较大的小型浮游植物在冬季和春季贡献率相对较高;从季节尺度看,浮游植物的平均粒级指数从大到小的顺序为:春季的(15.47μm),冬季的(11.08μm),秋季的(8.61μm),夏季的(6.52μm);尽管不同季节水文和化学环境差异显著,但是不同粒径浮游植物的贡献率随总生物量的变化表现出一致性的规律。对环境因子与叶绿素分布的相关分析表明,浮游植物的生长在夏季主要受到营养盐来源的限制,冬季主要受到水体混合引起的光照限制,秋季可能受到磷酸盐和水体混合的共同限制。浮游植物粒级结构的分布格局主要是由各组分在不同环境中的资源竞争优势决定的。