共查询到18条相似文献，搜索用时 140 毫秒
1.
1997—1998年EI—Nino至La—Nina期间东海黑潮的变异 总被引：3，自引：1，他引：3
基于日本“长风号”调查船在1997年与1998年10个航次的CTD资料，采用改进逆方法及改进动力计算方法对东海黑潮的流速、流量进行计算。1997年5月出现了EI－Nino现象，东海黑潮流量在1997年夏季减少，1997年东海黑潮的平均流量也减少。在1997年1月与6－7月，即EI-Nino现象出现前后，东海环流的流态有些不同。在1998年4月至11月黑潮在PN断面出现多流核心的结构，特别在10－11月出现3个流核心，黑潮主流核的位置秋季时东移。1995年与1998年都是东海黑潮异常年，这些异常现象可能与冲绳岛以南出现的反气旋涡的强度变化以及从EI－Nino现象过渡到La-Nina现象有关。 相似文献
2.
基于日本“长风号”调查船在 1 997与 1 998年 1 0个航次的CTD资料 ,采用改进逆方法及改进动力计算方法对东海黑潮的流速、流量进行计算 .1 997年 5月出现了El Ni no现象 ,东海黑潮流量在 1 997年夏季减少 ,1 997年东海黑潮的平均流量也减少 .在 1 997年 1月与 6— 7月 ,即El Ni no现象出现前后 ,东海环流的流态有些不同 .在 1 998年 4至 1 1月黑潮在PN断面出现多流核心的结构 ,特别在 1 0— 1 1月出现 3个流核心 ,黑潮主流核的位置秋季时东移 .1 995年与 1 998年都是东海黑潮异常年 ,这些异常现象可能与冲绳岛以南出现的反气旋涡的强度变化以及从El Ni no现象过渡到La Ni na现象有关 相似文献
3.
《中国科学:地球科学》2017,(8)
通过对台湾以东黑潮主流径及邻近东海海域2014年5~6月期间的调查,研究了海水中溶解钡(Ba)的地球化学分布特征,评估了黑潮对东海海水Ba的影响和输入通量,将Ba作为指示指标定量刻画了黑潮入侵东海的范围与程度.黑潮主流径各站位海水中溶解Ba垂直分布上从表层至深层浓度逐渐增高,浓度范围为4.91~19.2μg L~(-1).东海海域表层海水Ba浓度分布以近岸海域为最高,向外海逐渐降低;底层则出现近岸和外侧海域Ba浓度高,陆架中间海域Ba浓度低的现象.水交换模型估算得出黑潮水在5~10月间向东海的Ba输入通量共计为2.19×10~8kg,并以次表层水的输入通量为最大.调查海域Ba的分布特征指示黑潮在台湾东北部海域涌升,台湾海峡北向出水抑制黑潮表层水向东海陆架入侵,黑潮次表层水从陆架底层外侧逐渐影响东海.以溶解钡(Ba)作为端元估算参数计算得出,在调查期间,黑潮表层水对东海陆架区域影响不大,黑潮次表层水沿陆架底层向上爬升,从台湾东北海域沿陆架中部向西北方向侵入,形成一支黑潮入侵流,至钱塘江口附近黑潮水占比仍可达到65%左右.东海陆架底层外侧大部被黑潮水所控制,100m等深线以深处黑潮水能够占95%以上的比例.在台湾东北部DH9断面,黑潮次表层水从陆架坡折处沿底部向西侵入,黑潮水占比95%的位置可达122°E左右,垂直向上黑潮水所占比例越小.海水溶解Ba可以细致地刻画黑潮入侵东海的情景,其地球化学特性使其成为指示黑潮入侵东海的有效指标,为定量揭示黑潮与东海的相互作用提供了新的手段. 相似文献
4.
采用Green函数方法,高分辨率中国近海区域海潮模型和TOPO7.0全球海洋潮汐模型,以及Gutenberg-BullenA地球模型计算了负荷潮.结果表明,渤、黄、东海M2垂向位移负荷潮振幅最大值出现在浙江外海约150km处,其值超过28mm;次大值位于仁川湾,超过20mm;第三大值位于北黄海东北部,超过14mm.S2垂向位移负荷潮在上述三处的振幅值分别超过10,8和4mm.K1和O1垂向位移负荷潮振幅在琉球群岛中北部附近为最大,分别超过13和10mm:向内海逐渐减小.半日分潮垂向位移负荷潮基本上与海洋潮汐对应分潮具有相反的位相.在东海大部和南黄海东部全日分潮垂向位移负荷潮与对应的海潮分潮基本上具有反位相的关系,而在渤、黄海其余海域基本上不具有反位相关系.在研究海区内,全日潮的垂向位移负荷潮不出现无潮点.自吸-负荷平衡潮分布特征与垂向位移负荷潮相近,其振幅大约是垂向位移负荷潮的1.2~1.7倍,其位相与垂向位移负荷潮基本上相反.M2最大振幅值也出现在浙江外海,超过42mm. 相似文献
5.
基于2004~2006年12个航次的水文资料,用逆方法计算得到了奄美大岛以东AE断面琉球海流的流速和体积流量.再次证实琉球海流具有较稳定的次表层流核结构,流核位于110～600 m深度,并沿AE线分布于27.2°～28.2°N,流核的最大流速为15.1～80.0 cm·s-1. 12个航次的平均流速断面显示了一个完整的次表层流核,其流核的最大流速为21.3 cm·s-1, 流核的垂直和水平尺度分别为800 m 和 30 km. 观测结果表明,2004~2006年之间,琉球海流冬季、春季、夏季、秋季和年平均的流量分别为10.9,10.1,5.9,23.9和12.7×106 m3·s-1,秋季最强,夏季最弱.日本以南黑潮净流量为52.7×106 m3·s-1, 其中源于吐噶喇海峡黑潮和琉球海流的流量平均比为0.40. 相似文献
6.
南海北部东沙海底冲蚀河谷及其成因探讨 总被引：3，自引：0，他引：3
对覆盖南海北部东沙区的50多条多道地震剖面进行了解释.通过剖面解释,发现东沙隆起后,南海北部海底地形发生了较大变化.这其中包括东沙岛在陆架坡折处的隆起,以及沉积地层以较大的幅度向上翘起.向上翘起的地层在很大的范围内遭受海底剥蚀.在东沙隆起区的北侧,海底发育下切沟.本文解释为现代海底在更强烈的剥蚀条件下形成的海底冲蚀地形,称为海底冲蚀沟.海底冲蚀沟分布于东沙岛的北侧,大致与陆架坡折线,以及600m等深线相平行,其宽度一般在20km左右,NE-SW向长度可达200km,本文称为东沙海底冲蚀河谷.无论是冬季还是夏季,东沙岛以北的吕宋海峡都有黑潮分支从太平洋贯入南海.这一黑潮分支在冬季演化为太平洋-印度洋贯通流,在夏季演化为吕宋海峡次表层流.东沙海底冲蚀谷的分布与太平洋-印度洋贯通流,以及吕宋海峡次表层流的位置完全一致.本文认为,黑潮分支在遇到南海北部陆坡的阻挡后,黑潮水体由陆坡向陆架堆积,并因水深变浅,水体通过空间变小而使流速加大,从而有能力对海底产生剥蚀.东沙区海底地层的剥蚀,以及东沙海底冲蚀谷的发育都是黑潮分支在东沙陆架区形成的强底流和海底长期耦合作用的结果. 相似文献
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8.
从1997-1998年伽师强震群到2003年巴楚-伽师-岳普湖地震--震群演化特征及地震趋势分析 总被引：2，自引：0，他引：2
在介绍了1997—1998年伽师震群序列异常主要特征及其启示的基础上，对比分析了2003年以6．8级地震为主的巴楚一伽师一岳普湖地震序列的异同，认为巴楚一伽师6．8级地震序列和岳普湖5．8级地震分别是1997—1998年伽师震群在塔里木盆地内向东南和正南方向新的破裂扩展，两者虽互不相属，但均为1997—1998年伽师强震群向外扩展的产物。因而，1997—1998伽师强震群至今已发展成为。1997—2003年伽师-巴楚-岳普湖强震群”。对3次较大地震的扩展式空间迁移现象及其特征进行分析，推测伽师周围地区今后仍可能发生6级左右地震，指出可能的发震地点和中短期趋势。最后，提出了在该地区加强地震监测预报工作应该注意的几个问题。 相似文献
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10.
《中国科学:地球科学》2015,(12)
利用海表漂流浮标观测和高分辨率数值模式的示踪粒子试验,研究了黑潮在台湾东北入侵东海的路径及其季节变化规律.通过分析1989~2013年的海表漂流浮标数据,发现黑潮在台湾东北的表层入侵存在两条明显的路径:一条为沿台湾岛北岸的西北向入侵,另一条为陆坡转折附近的直接入侵;前者主要在冬季出现,而后者则全年都存在.高分辨率数值模式的示踪粒子试验印证了表面漂流浮标观测的结果,同时揭示了黑潮入侵的三维结构,给出了黑潮次表层水入侵的路径、特征和可能成因. 相似文献
11.
Long-term hydrographic temperature and salinity transect data in the East China Sea from June 1955 to November 2001 are analyzed
in order to examine the geostrophic velocity and the structure of the Kuroshio current. The structure of the Kuroshio Current
is divided into three basic forms, a single-core structure, a double-core structure and a multi-core structure; the appearance
percentage of the three forms are 53.1%, 31.4%, and 15.4%, respectively. The analysis suggests that multi-core structures
have significant seasonal and interannual variabilities that are not fully understood but may relate to variations in transport
and associated flow instabilities. The Kuroshio's spatial character is also analyzed in detail by applying a simplified model
of motion instability into this multi-core structure of the East China Sea Kuroshio. The theoretical results are found to
be consistent with the observations, suggesting that the instability of the Kuroshio in the East China Sea may bring forth
the formation of the observed multi-core structure. 相似文献
12.
East China Sea (ECS) is bounded by the continent where the fourth largest river of Changjiang discharges large amounts of freshwater to the west and by the Kuroshio in the East and connected to the South China Sea via Taiwan Strait, therefore water characteristics are very complex and undergo great seasonal changes. The dominant source waters in the ECS are found to be Kuroshio Surface Water (KSW), Kuroshio Sub-surface Water (KSSW), Changjiang Diluted Water (CDW), and Taiwan Strait Warm Water (TSWW). Optimum multiparameter analysis (OMP) using temperature, salinity and 226Ra were applied to quantify the contribution of individual source water to the surface water of the ECS in summer. The successful application of radium isotope in OMP analysis demonstrates the usefulness of 226Ra in the discrimination of mixing among multiple water sources. In 1987, one interesting phenomenon was that the KSSW entered the surface with the upwelling at the margin of continental shelf, and affected the coastal water obviously. In 1999, the TSWW extended northward continuously up to the Changjiang Estuary. 相似文献
13.
Daisuke Takahashi Xinyu Guo Akihiko Morimoto Shoichiro Kojima 《Continental Shelf Research》2009,29(15):1896-1907
An analysis of surface current data obtained from 2002 to 2005 using long-range high-frequency radar provides the first evidence for the presence of biweekly (11–14 day) periodic variations of the Kuroshio axis northeast of Taiwan. This analysis clarifies the spatiotemporal characteristics of these variations and reveals that cyclonic/anticyclonic eddies propagating along the shelf slope from the vicinity of the deep channel east of Taiwan induce these variations northeast of Taiwan. The behavior of the cyclonic/anticyclonic eddies on the shelf slope is well explained by 2nd-mode interior shelf waves advected by the Kuroshio's mean flow. Remote effects from the vicinity of the deep channel east of Taiwan, or from outside the East China Sea, are believed to play an important role in the generation of these biweekly periodic variations of the Kuroshio axis northeast of Taiwan. Moreover, on the shelf slope, these variations cause an onshore current across the shelf slope, suggesting topographically controlled upwelling. Therefore, the biweekly periodic variations of the Kuroshio axis northeast of Taiwan might contribute not only to the onshore transport of Kuroshio surface water but also to transport nutrient-rich Kuroshio subsurface water onto the shelf in the East China Sea. 相似文献
14.
Variability analysis of Kuroshio intrusion through Luzon Strait using growing hierarchical self-organizing map 总被引：3，自引：0，他引：3
An advanced artificial neural network classification algorithm is applied to 18?years of gridded mean geostrophic velocity multi-satellite data to study the Kuroshio intrusion into the South China Sea through the Luzon Strait. The results suggest that the Kuroshio intrusion may occur year round. However, intrusion is not the major characteristic of the region. The intrusion mode occurs only 25.8?% of the time. Winter intrusion events are more frequent than summer events. Both stronger intrusion (which is related to wind speed) and weaker intrusion (which may be related to the upstream Kuroshio transport) may occur during winter, but stronger intrusion is dominant. In summer, the Kuroshio intrusion is almost the weaker type. The Kuroshio intrusion through the Luzon Strait usually occurs when the Pacific decadal oscillation index is positive (72.1?% of the time). This study shows that growing hierarchical self-organizing map is a useful tool for analyzing Kuroshio intrusion through the Luzon Strait. 相似文献
15.
IntroductionTheEastChinaSea(ECS)regionisapartoftheoff-shorecontinentalshelfregionintheeasternpartofChina.AlthoughmiddleandstrongearthquakesoccurfrequentlytoitssoutheastintheregionofOkinawatroughandRyukyuislandarc,andevenmorefrequentlytoitssouthinTaiw... 相似文献
16.
LI TieGang SUN RongTao ZHANG DeYu LIU ZhenXia LI Qing & JIANG Bo Key Laboratory of Marine Geology Environment Institute of Oceanology Chinese Academy of Sciences Qingdao China Graduate School of Chinese Academy of Sciences Beijing China School of Resources & Environment Engineering Shandong University of Technology Zibo China The First Institute of Oceanography State Oceanic Administration Qingdao China 《中国科学D辑(英文版)》2007,50(5):725-735
The evolution and variation history of the Tsushima warm current during the late Quaternary was reconstructed based on the quantitative census data of planktonic foraminiferal fauna, together with oxygen and carbon isotope records of mixed layer dweller G. ruber and thermocline dweller N. dutertrei in piston core CSH1 and core DGKS9603 collected separately from the Tsushima warm current and the Kuroshio dominated area. The result showed that the Tsushima warm current vanished in the lowstand period during 40―24 cal ka BP, while the Kuroshio still flowed across the Okinawa Trough, arousing strong upwelling in the northern Trough. Meanwhile, the influence of freshwater greatly increased in the northern Okinawa Trough, as the broad East China Sea continental shelf emerged. The freshwater reached its maximum during the last glacial maximum (LGM), when the upwelling obviously weakened for the lowest sea-level and the depression of the Kuroshio. The modern Tsushima warm current began its development since 16 cal ka BP, and the impact of the Kuroshio increased in the middle and north- ern Okinawa Trough synchronously during the deglaciation and gradually evolved as the main water source of the Tsushima current. The modern Tsushima current finally formed at about 8.5 cal ka BP, since then the circulation structure has been relatively stable. The water of the modern Tsushima cur- rent primarily came from the Kuroshio axis. A short-term wiggle of the current occurred at about 3 cal ka BP, probably for the influences from the enhancement of the winter monsoon and the depression of the Kuroshio. The cold water masses greatly strengthened during the wiggle. 相似文献
17.
Evolution of an anticyclonic eddy southwest of Taiwan 总被引：8，自引：1，他引：7
Tingting Zu Dongxiao Wang Changxiang Yan Igor Belkin Wei Zhuang Ju Chen 《Ocean Dynamics》2013,63(5):519-531
Satellite images of sea-surface temperature, surface chlorophyll a concentration, and sea-level anomaly, together with ocean reanalysis data of Asia and Indian–Pacific Ocean (AIPOcean1.0), are utilized to study the three-dimensional characteristics and evolution of an anticyclonic warm eddy adjacent to the southwest coast of Taiwan during October and November 2006. Originated from the Kuroshio intrusion in the Luzon Strait, but unlike previously found westward moving anticyclonic eddies (AE) in the northeastern South China Sea, this AE was so close to the Taiwan coast and stayed where it was formed for over 1 month until it dissipated. Energy analysis is utilized to study the evolution process of the AE, and it shows that the barotropic instability (BTI) and baroclinic instability introduced by the Kuroshio intrusion flow appear to be the main energy sources for the AE. Periodical enhancement/relaxation of local northeasterly monsoon and its associated negative wind stress curl modify the current patterns in this region, reinforce the intraseasonal variability of the Kuroshio intrusion flow, and act together with Kuroshio to form the AE. Eddies detected from AIPOcean1.0 data also show that AEs are most likely to be generated southwest of Taiwan during the transition period of summer monsoon to winter monsoon, and generally, the BTI of Kuroshio intrusion contributes more than the direct wind stress work to the increase of the eddy kinetic energy for the generation and growth of the AEs. 相似文献
18.
应用美国宇航局Goddard地球观测系统四维资料同化系统、计算了我国大陆地区和近海海域1998年各月月平均能量收支各项和10m气温、比湿及风矢量的地理分布特征. 模式计算结果表明,地表短波净辐射最强出现在夏季(7月)新疆和西藏中部地区,高值中心区可达275W/m2,在黄海东海海域春季(4月)最大,其值为250W/m2左右. 地表长波净辐射最强出现在夏季(7月)我国西北地区,中心区值为125W/m2,我国近海海域在冬季(1月)最强,其值为75-100W/m2. 我国近海海面,冬季(1月)潜热通量值高于一般月份,中心区值可达250W/m2,夏季我国大陆西南、华北和东北一带为潜热通量高值区,其值为125W/m2. 月平均能量收支计算结果显示,在黄海、东海海域冬季(1月)净通量为海洋向大气输送,夏季(7月)则反之,新疆和西藏高原中部夏季为净通量正值区. 综合温度、湿度和风矢量场分布发现,夏季从南海向华东地区,孟加拉湾向印度次大陆有明显的水汽平流输送,西藏西南部也有来自西南方向的水汽输送. 相似文献