台湾以东黑潮的低频变化及机制研究   总被引：1，自引：0，他引：1  

许灵静  齐继峰  尹宝树  杨德周  陈海英 《海洋学报》2017,39(9):15-25

本文基于AVISO（Archiving, Validation and Interpretation of Satellite Oceanographic data）1993-2015年间的海表面绝对动力高度数据,研究了台湾以东黑潮的低频变化特征,并探讨了影响其变化的机制。结果表明,台湾以东多年平均的黑潮流幅值约为136 km,表层流量值约为7.75×104 m2/s,对应的标准差分别为28 km和2.14×104 m2/s。台湾以东黑潮不仅具有显著的季节变化特征,还具有显著的年际变化特征。功率谱分析结果表明,台湾以东黑潮表层流量具有1 a和2.8 a的显著周期。空间上,台湾东南部黑潮的年际变化幅度比东北部强烈。相关性及合成分析结果表明,台湾以东黑潮的年际变化与PTO（Philippines-Taiwan Oscillation）之间存在显著的相关性。PTO年际震荡所导致的副热带逆流区反气旋式涡旋与气旋式涡旋的相对强度是影响台湾以东黑潮年际变化的主要动力因素。  相似文献   

长江口及其邻近海域有害藻华的发生情况、危害效应与演变趋势   总被引：3，自引：0，他引：3  

于仁成  张清春  孔凡洲  周正熙  陈振帆  赵越  耿慧霞  代丽  颜天  周名江 《海洋与湖沼》2017,48(6):1178-1186

长江口及其邻近海域是我国近海有害藻华高发区之一。自2000年以来,由东海原甲藻(Prorocentrum donghaiense)、米氏凯伦藻(Karenia mikimotoi)和亚历山大藻(Alexandrium spp.)等甲藻形成的大规模有害藻华连年暴发,对海水养殖业、人类健康和生态安全构成了严重威胁。以往调查和研究工作表明,长江口及其邻近海域藻华优势类群近年来已由硅藻逐渐转变为甲藻,同时,有害藻华原因种也表现出明显的年际变异特征和有毒有害藻种增多的态势,亟待解析其演变机理、趋势和驱动因素。长江口及其邻近海域受长江径流影响,富营养化问题突出,是大规模有害藻华形成的重要原因。同时,该海域也受到来自台湾东北部黑潮分支的影响,但对其与有害藻华的关系所知甚少。在中国科学院战略性先导科技专项"热带西太平洋海洋系统物质能量交换及其影响"支持下,针对这一问题开展了较为系统的调查和研究工作,本文对研究中得到的科学认识进行了初步总结。结果表明:东海黑潮分支能够到达长江口及其邻近海域赤潮区,影响该海域赤潮生物多样性状况;黑潮分支对长江口及其邻近海域甲藻赤潮发生过程具有重要调控作用;长江冲淡水和黑潮分支的共同作用决定了长江口及其邻近海域有害藻华的发生过程和演变趋势。在现有结果基础上进一步分析和讨论了未来长江口及其邻近海域有害藻华的研究方向,以期为进一步解析有害藻华演变趋势、提升有害藻华的监测和预警能力提供依据。  相似文献   

Sensitivity study of the seasonal mean circulation in the northern South China Sea   总被引：5，自引：0，他引：5  

宏波  王东晓 《大气科学进展》2008,25(5):824-840

A study of the circulation in the northern South China Sea （SCS） is carried out with the aid of a three-dimensional, high-resolution regional ocean model. One control and two sensitivity experiments are performed to qualitatively investigate the effects of surface wind forcing, Kuroshio intrusion, and bottom topographic influence on the circulation in the northern SCS. The model results show that a branch of the Kuroshio in the upper layer can intrude into the SCS and have direct influence on the circulation over the continental shelf break in the northern SCS. There are strong southward pressure gradients along a zonal belt largely seaward of the continental slope. The pressure gradients are opposite in the southern and northern parts of the Luzon Strait, indicating inflow and outflow through the strait, respectively. The sensitivity experiments suggest that the Kuroshio intrusion is responsible for generating the imposed pressure head along the shelf break and has no obvious seasonal variations. The lateral forcing through the Luzon Strait and Taiwan Strait can induce the southwestward slope current and the northeastward SCS Warm Current in the northern SCS. Without the lateral forcing, there is the continental slope. The wind forcing mainly causes the The wind-induced water pile-up results in the southward no high-pressure-gradient zonal belt seaward of seasonal variation of the circulation in the SCS. high pressure gradient along the northwestern boundary of the basin. Without the blocking of the plateau around Dongsha Islands, the intruded Kuroshio tends to extend northwest and the SCS branch of the Kuroshio becomes wider and stronger. The analyses presented here are qualitative in nature but should lead to a better understanding of the oceanic responses in the northern SCS to these external influence factors.  相似文献   

台湾岛附近海洋对0908号台风“莫拉克”的响应特征   总被引：1，自引：1，他引：0  

赖巧珍  马雷鸣  黄伟  吴立广 《海洋学报》2013,35(3):65-77

在模拟2009年登陆我国东部沿海的台风"莫拉克"的基础上,利用AVHRR/AMSR和SODA再分析数据和模拟结果,初步评估了GRAPES-ECOM海-气耦合模式(上海台风研究所基于GRAPES-TCM区域台风模式和ECOM海洋模式开发而成)模拟台风期间海洋响应的能力,并分析了台风期间台湾岛周围海域的海温、上升流、中尺度冷涡等的变化特点。分析结果表明,GRAPES-ECOM耦合模式较好地模拟了表层海温对台风的响应,与深水海洋响应比较,揭示了近海对台风响应的一些新特征:(1)在台湾以东海域,台风活动改变了黑潮海域海水的垂直运动,诱导黑潮南部沿岸上升流,而北部先于台风存在的上升流减弱,导致不同水深海温的最大降温位置都出现在路径左侧,与深海偏向路径右侧不同;(2)位于台湾岛东北面的彭佳屿冷涡因其形成与大陆架和黑潮有关,当台风在台湾以东洋面活动时,冷涡位于台风右前方,黑潮表层海水辐合流向大陆架,冷涡中心温度上升,强度减弱,当台风转折北上,冷涡位于台风东南侧,表层海水辐散,加强底层冷水上涌,从而增强了该冷涡的强度;(3)台风不仅加深了台湾海峡的混合层深度,还使得海水的垂直热力结构改变,并使整层海温趋于一致。  相似文献   

黑潮及相邻海域表层砂壳纤毛虫分布模式:以夏季黄海、东海至西太平洋断面为例   总被引：1，自引：0，他引：1  

宣俊  李海波  王超锋  董逸  赵苑  赵丽  张武昌 《海洋科学》2022,46(2):28-36

2019年夏季对沿黄、东海至西太平洋跨越黑潮一个断面(122°E～145°E)的表层砂壳纤毛虫群落进行调查,研究了黑潮中砂壳纤毛虫与相邻水体的差异.根据水文环境及各站位所处的空间位置,我们将研究区域划分为大洋边缘区域、黑潮区域和大洋区域.各站位砂壳纤毛虫的丰度范围为3.95～31.94 ind·L–1,种丰富度范围为6...  相似文献   

Optimal precursor of the transition from Kuroshio large meander to straight path     

王强  马利斌  徐强强 《中国海洋湖沼学报》2013,31(5):1153-1161

We used the conditional nonlinear optimal perturbation(CNOP) method to explore the optimal precursor of the transition from Kuroshio large meander(LM) to straight path within a barotropic inflowoutflow model,and found that large amplitudes of the optimal precursor are mainly located in the east of Kyushu,which implies that perturbations in the region are important for the transition from LM to straight path.Furthermore,we investigated the transition processes caused by the optimal precursor,and found that these processes could be divided into three stages.In the first stage,a cyclonic eddy is advected to the formation region of the Kuroshio large meander,which enhances the LM path and causes a cyclonic eddy to shed from the Kuroshio mainstream.This process causes the LM path to change into a small meander path.Subsequently,the small meander is maintained for a period because the vorticity advection is balanced by the beta effect in the second stage.In the third stage,the small meander weakens and the straight path ultimately forms.The positive vorticity advecting downstream is responsible for this process.The exploration of the optimal precursor will conduce to improve the prediction of the transition processes from LM path to straight path,and its spatial structure can be used to guide Kuroshio targeted observation studies.  相似文献   

台湾岛以东海域束毛藻种群的组成与分布   总被引：2，自引：0，他引：2  

王雨  林茂  杨清良  林更铭 《海洋通报》2012,31(4):426-432

分别对1996年5月和1997年7月台湾岛以东黑潮及邻近海域51个采样站位的87份网采浮游植物进行了分析,总结了束毛藻种群的物种构成和丰度分布特征,并初步探讨了水动力条件、温盐、营养盐及其他元素对束毛藻生长及分布的影响.结果表明,调查区的束毛藻种群由铁氏束毛藻(Trichodesmium thiebautii)、汉氏束毛藻(Trichodesmium hildebrandtii)和红海束毛藻(Trichodesmium erythraeum)组成,前者分布最为普遍,检出率100%,丰度最大.1996年5月束毛藻平均藻丝体密度为44.55伊102 filaments/m3,铁氏束毛藻占91%,在吕宋海峡密集,总体呈现西南高,东北低的分布态势.1997年7月束毛藻平均藻丝体密度为152.72伊102 filaments/m3,铁氏束毛藻占99%,除吕宋海峡外,台湾东北部海域为次高值区,总体呈现西南高,中部和东部低的分布态势.较之邻近海区结果,台湾岛以东黑潮及邻近海域的束毛藻平均藻丝体密度高于太平洋赤道热带海域、南黄海和东海陆架区、东海产卵场,低于台湾海峡西侧20 m 以浅和东海低氧区.在台湾岛以东海域,束毛藻的丰度分布由其特定的地理位置和黑潮流向所决定,高温高盐的黑潮水系利于束毛藻的增殖,束毛藻的丰度分布与 Fe、P 等化学因子的关系有待进一步寻找证据.  相似文献   

Vorticity budget study on the seasonal upper circulation in the northern South China Sea from altimetry data and a numerical model   总被引：1，自引：0，他引：1  

CAI Shuqun  ZHENG Shu  HE Yinghui 《中国海洋大学学报(英文版)》2012,11(4):455-464

Based on the EOF analyses of Absolute Dynamic Topography satellite data,it is found that,in summer,the northern South China Sea(SCS) is dominated by an anticyclonic gyre whilst by a cyclonic one in winter.A connected single-layer and two-layer model is employed here to investigate the dynamic mechanism of the circulation in the northern SCS.Numerical experiments show that the nonlinear term,the pressure torque and the planetary vorticity advection play important roles in the circulation of the northern SCS,whilst the contribution by seasonal wind stress curl is local and limited.Only a small part of the Kuroshio water intrudes into the SCS,it then induces a positive vorticity band extending southwestward from the west of the Luzon Strait(LS) and a negative vorticity band along the 200 m isobath of the northern basin.The positive vorticity field induced by the local summer wind stress curl is weaker than that induced in winter in the northern SCS.Besides the Kuroshio intrusion and monsoon,the water transports via the Sunda Shelf and the Sibutu Passage are also important to the circulation in the northern SCS,and the induced vorticity field in summer is almost contrary to that in winter.The strength variations of these three key factors(Kuroshio,monsoon and the water transports via the Sunda Shelf and the Sibutu Passage) determine the seasonal variations of the vorticity and eddy fields in the northern SCS.As for the water exchange via the LS,the Kuroshio intrusion brings about a net inflow into the SCS,and the monsoon has a less effect,whilst the water transports via the Sunda Shelf and the Sibutu Passage are the most important influencing factors,thus,the water exchange of the SCS with the Pacific via the LS changes dramatically from an outflow of the SCS in summer to an inflow into the SCS in winter.  相似文献   

黑潮源区沉积物古菌多样性调查及研究     

景天爽  于心科 《地质学报》2012,86(12):2011-2019

为了研究西太平洋黑潮源区不同深度沉积物中古菌群落结构的多样性,应用16S rDNA文库技术,对IMAGES XIV航次采集的岩芯MD06-3047进行基因文库的构建和分析,得到260个克隆,经分析处理后得到56个OTUs(Operational Taxonomic Units).基于16S rRNA序列的同源性比较,绘制系统进化树,进行统计学分析.研究结果显示,西太平洋黑潮源区的本哈姆高原(Benham Rise)沉积物中有丰富多样的古菌群落,在1m内的沉积物中分布着9种古菌类群.古菌序列归属于泉古菌(Crenarchaeota)和广古菌(Euryarchaeota),并以泉古菌为主(占总序列的91.5％).其中,泉古菌包含MGI、MBG-B、MCG和UCII-b 4个类群,并且主要由MGI构成(占总序列的40.8％),而广古菌包含MBG-D、SAGMEG、DHVEG、MBG-E和VAL Ⅲ 5个类群,各类群所占总序列比例均较低(占总序列的0.4％～5.4％之间).研究结果对于理解西太平洋黑潮源区沉积物中古菌多样性有重要意义,并为今后研究古菌群落与环境之间的关系提供科学依据.  相似文献   

冬季黑潮延伸体异常增暖对东亚夏季风影响的数值试验   总被引：3，自引：1，他引：3  

王晓丹  钟中  谭言科  杜楠 《热带气象学报》2011,27(4):569-576

利用NCAR CAM3全球大气环流模式数值试验，研究了冬季黑潮延伸体的海温异常增暖对东亚夏季风的影响。结果表明，冬季黑潮延伸体海温异常增暖将导致东亚夏季风增强北推。表征夏季风强度的EASMI（the East Asian Summer Monsoon Index）和LSTDI（the Land-Sea Thernal Difference Index）在夏季风爆发后都呈现了明显的增强趋势，且LSTDI对海温异常增暖的响应更为敏感。华北、南海和菲律宾以东的低空西南季风显著增强，副热带西风急流轴以北（南）西风加强（减弱）。日本群岛及周边海域和中国东部长江以南至秦岭一线的降水明显减少；华北、南海、东海、黄海和菲律宾以东的西太平洋上的降水增多。华北是东亚夏季风对黑潮延伸体的海温异常响应最敏感的区域。东亚地区近地面温度表现为一致的增温特征，而30～50 °N之间对流层的整体升温导致了海陆热力差异的加大，这是促使东亚夏季风增强的重要原因。中国及周边地区环流和降水异常分布和西北太平洋副热带高压增强北抬有关。  相似文献