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The relationship between SST in the Eastern Pacific and equatorial wind fields in the Western Pacific is analysed by using COADS.It is pointed out that in the year before El Nino , the continuative easterly anomalies and the meridional anomalies blowing from the Equator to both sides in the Equatorial Western Pacific cause the sea level in the Western Pacific to rise higher than in the Eastern Pacific and the sea level at the Equator to drop lower than on both sides of it. In the El Nino year, the westerly anomalies and the meridional anomalies blowing from both sides to the Equator bring warm water to build up around the Equator. At such times Kelvin waves are generated and they play an important role in raising SST in the Eastern Pacific. It is also emphatically pointed out that in the El Nino year the two maxima of the equatorial westerly anomalies, the two cross-equatorial air flows from the Northern Hemisphere to the Southern one and the two maxima of the near-equatorial tropical cyclones in the Eq 相似文献
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On the relationship between convection intensity of South China Sea summer monsoon and air-sea temperature difference in the tropical oceans 总被引：5，自引：4，他引：1
The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is discussed using two data sets of 48-a SODA (simple ocean data assimilation) and NCEP/NCAR. Analyses show that in wintertime Indian Ocean (WIO), springtime central tropical Pacific (SCTP) and summertime South China Sea-West Pacific (SSCSWP), air-sea temperature difference is significantly associated with the convection intensity of South China Sea summer monsoon. Correlation of the inter-decadal time scale (above 10 a) is higher and more stable. There is inter-decadal variability of correlation in scales less than 10 a and it is related with the air-sea temperature difference itself for corresponding waters. The inter-decadal variability of the convection intensity during the South China Sea summer monsoon is closely related to the inter-decadal variability of the general circulation of the atmosphere. Since the late period of the 1970s, in the lower troposphere, the cross-equatorial flow from the Southern Hemisphere has intensified. At the upper troposphere layer, the South Asian high and cross-equatorial flow from the Northern Hemisphere has intensified at the same time. Then the monsoon cell has also strengthened and resulted in the reinforcing of the convection of South China Sea summer monsoon. 相似文献
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A review on the South China Sea western boundary current 总被引：7，自引：2，他引：5
The advances in understanding the South China Sea (SCS) western boundary current (SCSwbc) have been reviewed since the works of Dale (1956) and Wyrtki (1961) in the middle of the 20th century. The features of the pattern of SCSwbc and the oceanic phenomena associated with it are focused on. The current is driven mainly by monsoon over the SCS and partially by winds over the tropical Pacific governed by the island rule. The SCSwbc exhibits strong seasonal variation in its direction and patterns. In winter, the current is strong and flows southwestward along the South China shelf and slope from the east of Dongsha Islands to the northern central Vietnamese coast, then turns to the south along the central and southern Vietnamese coast, and finally partially exits the SCS through the Karimata Strait. In summer and early fall, the SCSwbc can be divided into three segments based on their characteristics. The southern segment is stable, flowing northward from the Karimata Strait up to about 11 N, where it separates from the coast forming an eastward offshore current. The separation of the current from Vietnamese coast induces some striking features, such as upwelling and cold sea-surface temperature. The middle segment off the central Vietnamese coast may have a bimodal behavior: northward coastal current and meandering current in early summer (June-July), and cyclonic gyre in later summer and early fall (August-September). The northern segment is featured by the summer SCS Warm Current on the South China shelf and a southwestward subsurface current along the continental slope. 相似文献
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The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is discussed using two data sets of 48-a SODA (simple ocean data assimilation) and NCEP/NCAR. Analyses show that in wintertime Indian Ocean (WIO), springtime central tropical Pacific (SCTP) and summertime South China Sea-West Pacific (SSCSWP), air-sea temperature difference is significantly associated with the convection intensity of South China Sea summer monsoon. Correlation of the inter-decadal time scale (above 10 a) is higher and more stable. There is interdecadal variability of correlation in scales less than 10 a and it is related with the air-sea temperature difference itself for corresponding waters. The inter-decadal variability of the convection intensity during the South China Sea summer monsoon is closely related to the inter-decadal variability of the general circulation of the atmosphere. Since the late period of the 1970s, in the lower troposphere, the cross-equatorial flow from the Southern Hemisphere has intensified. At the upper troposphere layer, the South Asian high and cross-equatorial flow from the Northern Hemisphere has intensified at the same time. Then the monsoon cell has also strengthened and resulted in the reinforcing of the convection of South China Sea summer monsoon. 相似文献
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我们用Non—Boussinesq POP海洋模式和NECP 1000 hPa的风应力和气温场资料，模拟了1960—1999年太平洋环流，结果显示：在过去的40年，热带太平洋环流变弱了，另外，由于全球变暖，由北赤道流产生的向热带西太平洋沿岸的热输送和由南赤道流产生的向南太平洋中高纬度的热输送随着时间是减弱的，而在北半球，由北赤道流产生的向中高纬度的热输送是增加的。 相似文献
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捻螺科(Acteonidae = Pupidae)是一群有壳后鳃类软体动物。它们的侧脏神经索在发育过程中没有象其它后鳃类那样再经过逆转，仍然保持着不对称而互相交叉呈“8”形；它们具有螺旋形的外壳，身体能完全缩入壳内，具有角质厣。这些都表明它们在演化上仍保留着前鳃类的特征，所以是一群原始类型的后鳃类。
这科动物在潮间带与潮下带浅水区，直至水深数百米的泥砂质海底营底栖生活。由于它们具有较坚固的贝壳，所以在海底沉积物及地层化石中也常见到。它们广泛分布于世界各海域，尤其在印度－太平洋区种类较多。它们大多是暖水性种，有些既是化石种又是现生种。
在我国已报道5属，共14种, 在报道过的14种中有2种——Acteon secale, A. mariae 我们尚未找到标本。
本文根据中国科学院海洋研究所历年来在我国沿海潮间带调查采集、潮下带底栖生物调查及东海地质取样中所获得的标本，选行整理鉴定，共有20种，分隶于5属；其中有2新种，6个新记录。在这些种类中，有5种分布于印度－太平洋区：坚固蛹螺 Pupa solidula，纵沟蛹螺 P. sulcata，红斑蛹螺 P. coccinata，火焰斑捻螺 Punctacteon flammeus，线红纹螺 Bullina lineata；其余的种均为西太平洋种。同日本共有的种为14种，其中5种是日本－中国特有种：卵圆捻螺 Acteon teramachii，吉良斑捻螺 A. kirai，希氏捻螺 A siebaldii ，宽带斑捻螺 Punctacteon kajiyamai，华贵红纹螺 Bullina nabilis。在这些种类中，仅黑纹斑捻螺可向北分布到黄海、渤海。可见我国的这科动物为暖水性种，在区系上与日本南部关系极为密切。 相似文献
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In this paper observational data are used to compute drift and geostrophic current components and to evaluate water transport
in the upper 0–800 m ocean layer. Water circulation in the south-western Indian Ocean has been shown to differ from the circulation
in similar areas of the Atlantic and Pacific Oceans. The West Australian current, closing the anticyclonic gyre, is an intervening
flow. On the other hand, within the upper 200 m layer, the current flows southward along the West Australian coast, thereby
producing specific hydrological conditions in that region.
Translated by Vladimir A. Puchkin. 相似文献
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Equatorially trapped Rossby waves in the presence of meridionally sheared baroclinic flow in the Pacific Ocean 总被引：1，自引：0，他引：1
TOPEX/POSEIDON altimeter data are analyzed for the 8.5-year period November 1992 to May 2001 to investigate the sea surface height (SSH) and geostrophic velocity signatures of quasi-annual equatorially trapped Rossby waves in the Pacific. The latitudinal structures of SSH and both components of geostrophic velocity are found to be asymmetric about the equator across the entire Pacific with larger amplitude north of the equator. The westward phase speeds are estimated by several different methods to be in the range 0.5-0.6 m s−1. These observed characteristics are inconsistent with the classical theory for first vertical, first meridional mode equatorially trapped Rossby waves, which predicts a phase speed of about 0.9 m s−1 with latitudinally symmetric structures of SSH and zonal velocity and antisymmetric structure of meridional velocity. The observations are even less consistent with the latitudinal structures of SSH and geostrophic velocity components for other modes of the classical theory.The latitudinal asymmetries deduced here have also been consistently observed in past analyses of subsurface thermal data and altimeter data and have been variously attributed to sampling errors in the observational data, a superposition of multiple meridional Rossby wave modes, asymmetric forcing by the wind, and forcing by cross-equatorial southerly winds in the eastern Pacific. We propose a different mechanism to account for the observed asymmetric latitudinal structure of low-frequency equatorial Rossby waves. From the free-wave solutions of a simple 1.5-layer model, it is shown that meridional shears in the mean equatorial current system significantly alter the potential vorticity gradient in the central and eastern tropical Pacific. The observed asymmetric structures of sea surface height and geostrophic velocity components are found to be a natural consequence of the shear modification of the potential vorticity gradient. The mean currents also reduce the predicted westward phase speed of first meridional mode Rossby waves, improving consistency with the observations. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2013,36(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
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薛春汀 《海洋地质与第四纪地质》2002,22(2):121-125
珊瑚礁海岸海滩和礁坪是海岸作用是活跃的部分，也是近几十年来与海岸发育，海岸侵蚀联系最密切的部分，这一部分高潮时被淹没，低潮时完全出露或大部分出露，使得在此进行地质填图成为可能，这样的地质图可以提供许多信息，如沉积物粒度分布规律，沉积物来源和搬运方向，海滩岩所指示的古海岸线位置，人类活动特别是海岸工程对沉积物分布的影响以及海岸线的变化过程和趋势，在礁坪上开挖的人工水道内测流，能够了解水流的性质以及是否有足够的速度搬运沉积物，从而了解人工水道对海岸的影响和预测海岸的状态，这些方法也可以用于大陆泥质和砂质第岸侵蚀的研究。 相似文献
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西太平洋暖池热含量与南海夏季风强度的关系 总被引：2，自引：1，他引：1
为了进一步明确西太平洋暖池热含量对南海夏季风强度的影响,利用1948~2012年日本气象厅(japan meteorological agency,JMA)逐月的海温资料、Hadley中心的海表面温度(Sea Surface Temperature,SST)资料以及NCEP/NCAR再分析资料,分析比较了南海夏季风强度与热带太平洋上层海洋热含量和SST的关系;探讨了海洋热含量影响南海夏季风强度的机制。结果表明:(1)相比于西太暖池SST,西太暖池上层海洋热含量是南海夏季风强度更好的预测因子;(2)前期冬春季的西太平洋暖池热含量与南海夏季风强度呈现显著的正相关,尤其在3月,二者相关系数最大;当暖池热含量偏高(低)时,西太平洋副热带高压偏弱(强),赤道印度洋出现异常反气旋(气旋),印度洋上空的Walker环流分支偏强(弱),南海越赤道气流增强(减弱),最终使得南海夏季风强度偏强(弱)。 相似文献
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HF radar detection of tsunamis 总被引：1，自引：0，他引：1
Belinda J. Lipa Donald E. Barrick John Bourg Bruce B. Nyden 《Journal of Oceanography》2006,62(5):705-716
This paper demonstrates that HF radar systems can be used to detect tsunamis well before their arrival at a coastline. We
solve the equations of motion and continuity on the ocean surface using models to simulate the signals produced by a tsunami
approaching the east U.S. coast. Height and velocity profiles are derived along with expressions for the radar-observed current
velocities in terms of bathymetry and tsunami height and period. Simulated tsunami-generated radial current velocities are
superimposed on typical maps of radial velocity generated by a Rutgers University HF radar system. A detection parameter is
defined and plotted to quantify the progress of the tsunami, which is shown to be detectable well before its arrival at the
coast. We describe observations/warnings that would have been provided by HF radar systems at locations in the path of the
2004 Indian Ocean tsunami. 相似文献
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The Chukchi and Beaufort Seas include several important hydrological features： inflow of the Pacific water, Alaska coast current （ ACC ）, the seasonal to perennial sea ice cover, and landfast ice ＇along the Alaskan coast. The dynamics of this coupled ice-ocean system is important for both regional scale oceanography and large-scale global climate change research. A mumber of moorings were deployed in the area by JAMSTEC since 1992, and the data revealed highly variable characteristics of the hydrological environment. A regional high-resolution coupled ice-ocean model of the Chukchi and Beaufort Seas was established to simulate the ice-ocean environment and unique seasonal landfast ice in the coastal Beaufort Sea. The model results reproduced the Beaufort gyre and the ACC. The depthaveraged annual mean ocean currents along the Beaufort Sea coast and shelf hreak compared well with data from four moored ADCPs, but the simulated velocity had smaller standard deviations, which indicate small-scale eddies were frequent in the region. The model resuits captured the sea,real variations of sea ice area as compared with remote sensing data, and the simulated sea ice velocity showed an ahnost stationary area along the Beaufort Sea coast that was similar to the observed landfast ice extent. It is the combined effects of the weak oceanic current near the coast, a prevailing wind with an onshore component, the opposite direction of the ocean current, and the blocking hy the coastline that make the Beaufort Sea coastal areas prone to the formation of landfast ice. 相似文献
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D. S. Drozdov F. M. Rivkin V. Rachold G. V. Ananjeva-Malkova N. V. Ivanova I. V. Chehina M. M. Koreisha Yu. V. Korostelev E. S. Melnikov 《Geo-Marine Letters》2005,25(2-3):81-88
A set of digital maps including geology, Quaternary sediments, landscapes, engineering-geological, vegetation, geocryological and the series of regional sources have been selected to characterize the Russian Arctic coast. Based on this data, new maps of engineering geocryological zoning and zoning of the coast with respect to the intensity of exogenous geological processes and risk of technogenic impacts have been generated at the scales of 1:4,000,000–1:8,000,000. These maps are a tool to assess the impact of industry on the Arctic coast of the country. 相似文献
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用Non-Boussinesq POP模式和1960—1999年NCEP的1 000 hPa大气温度和风场资料,模拟了最近40 a太平洋海温的变化,通过与实际观测结果比较,得出模拟结果是可信的,并且得到了一些有意义的结果:在海面,太平洋最大的增温发生在赤道中东太平洋,即Niño1-Niño4区内,最大的降温在中纬度南北太平洋中部,除了北半球太平洋西岸40°N附近为降温外,在北半球太平洋沿岸基本上为升温,但太平洋东海岸的升温幅度要远大于西海岸;在太平洋0~483 m深度垂直方向,除了赤道中太平洋区域海温的变化在海面为上升,在169 m处为下降,在483 m处又转为上升外,其他区域海温的变化在垂直方向基本上为线性变化。在全球增暖的背景下,虽然El Niño现象在20世纪90年代以后表现出增强的趋势,但是反映在赤道表面以下的次表层西太平洋暖池中的异常暖中心,在由西向东移动过程中其强度却是减弱的。 相似文献
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The 2015/2016 El Ni?o event reached the threshold of super El Ni?o event, and was comparable to the super events in 1982/1983 and 1997/1998. Interestingly, the tropical cyclones(TCs) were found to have very late onsets in the decaying years of the super El Ni?o events. This study discusses the causes of late TC onsets related with atmospheric circulation, disturbance sources and trigger mechanisms. The analysis shows that the western North Pacific subtropical high(WNPSH) from January–June during the decaying years of the super El Ni?o events were stronger than the climatic mean, which resulted in a relatively stable atmospheric state by inhibiting deep convection. As a disturbance source, the April–June intertropical convergence zone(ITCZ) during the decaying years of the super El Ni?o events were significantly weaker than its climatic mean. The cross-equatorial flow and monsoon trough, as important TC generation triggers, were weaker from April–June during the decaying years of the super El Ni?o events, which further reduced the probability of TC generation. As for the late TC onsets, the role of atmospheric circulation anomalies(i.e., subtropical-high, the ITCZ, cross-equatorial flow, and monsoon trough) were more important. The cross-equatorial flow may take as predictor of TC onsets in the decaying years of the super El Ni?o events. 相似文献