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1.
Spatiotemporal characteristics of interannual temperature variations in the Tsushima Strait are investigated on the basis of historical hydrographic data applying the same procedures as Senjyu et al. (2006). Empirical orthogonal function (EOF) analysis revealed that the most energetic mode of variation (the EOF first mode), which accounts for about 31.5% of the total variance, is the in-phase temperature change for the entire strait. The wintertime temperature variation described by the first mode is associated with the wintertime heat flux in the northern East China Sea, while they are poorly correlated in other seasons. The large standard deviation in the time coefficient of the first mode in August suggests a relationship with the horizontal heat advection in summer in the northern East China Sea. On the other hand, the EOF second mode, which explains about 12.6% of the total variance, is associated with the stratification and baroclinicity in the strait. The time coefficient of the EOF second mode negatively correlates with the baroclinic volume transport through the strait in summer. Comparison of temporal variations among the leading EOF modes for temperature and salinity shows no significant correlations. This indicates that the principal modes of variation in temperature and salinity vary independently within an interannual timescale.  相似文献   

2.
Interannual salinity variations in the Tsushima Strait are investigated on the basis of historical hydrographic data. The EOF analysis revealed that the most dominant mode is the in-phase salinity variation between the eastern and western channels. The time coefficients of the EOF first mode in summer show a negative correlation with the Changjiang discharge, which indicates that salinity in the Tsushima Strait tends to decrease over summer, related to a large discharge of the Changjiang. The eigenvectors of the first mode are larger in the eastern channel than those in the western channel, though the low salinity water mainly flows through the western channel. This is because the low salinity water spreads into the eastern channel as well as the western channel over summers with a large discharge of the Changjiang. The out-of-phase salinity variation between the channels is extracted as the EOF second mode; this is the predominant variation in the western channel. The time coefficients of the second mode in summer show no significant correlations to the volume transports through the western channel and the transport differences between channels. A relationship between the EOF second mode and variations in the wind stress over the East China Sea is suggested.  相似文献   

3.
1 IntroductionThe variability of the air -sea system orches-trates a complex climate system of our earth, andthis variability gives rise to an array of naturally oc-curring dynamical modes at different time scales.These modes are important attributes of c…  相似文献   

4.
采用TOPEX/POSEIDON(T/P)卫星高度计 1 993年 1月— 2 0 0 0年 1 2月海面高度数据 ,研究包含了整个南极绕极流流系 (40°— 6 0°S)的海面高度低频变化。首先采用EOF分解方法获取南大洋时空分布的主要模态 ,前 3个EOF模态分别占总方差的 2 4 .8%、1 3 .8%和 1 0 .7%。然后采用EMD方法分别分析了各个EOF模态的时间系数曲线的组成成分 ,对南极绕极流海域的各种时间尺度变化给出了清晰的描述 ,对于不同尺度变化所占的比例得到了定量的结果。研究结果表明 ,EOF的各个模态不仅在形态上存在差异 ,而且具有相互独立的物理背景。EOF的第一模态主要体现了以太阳辐射冬夏差异形成的年周期变化 ,另一个显著的特征就是南极绕极流从 1 993— 2 0 0 0年海面的整体上升趋势。EOF的第二模态体现了陆地地形对南极绕极流的约束作用 ,同时也显示了ENSO过程对南极绕极流 ,特别是对南太平洋的海面高度变化的影响。EOF的第三模态则体现了南极绕极流对南大洋表面风场东西方向不均匀变化的响应。同时 ,本文的研究也证明了EOF与EMD方法联合使用对揭示大范围时空变化有重要的实际意义  相似文献   

5.
The spatial structure of surface air temperature (SAT) anomalies in the extratropical latitudes of the Northern Hemisphere (NH) during the 20th century is studied from the data obtained over the period 1892–1999. The expansion of the mean (over the winter and summer periods) SAT anomalies into empirical orthogonal functions (EOFs) is used for analysis. It is shown that variations in the mean air temperature in the Arctic region (within the latitudes 60°–90°N) during both the winter and summer periods can be described with a high accuracy by two spatial orthogonal modes of variability. For the winter period, these are the EOF related to the leading mode of variability of large-scale atmospheric circulation in the NH, the North Atlantic Oscillation, and the spatially localized (in the Arctic) EOF, which describes the Arctic warming of the mid-20th century. The expansion coefficient of this EOF does not correlate with the indices of atmospheric circulation and is hypothetically related to variations in the area of the Arctic ice cover that are due to long-period variations in the influx of oceanic heat from the Atlantic. On the whole, a significantly weaker relation to the atmospheric circulation is characteristic of the summer period. The first leading variability mode describes a positive temperature trend of the past decades, which is hypothetically related to global warming, while the second leading EOF describes a long-period oscillation. On the whole, the results of analysis suggest a significant effect of natural climatic variability on air-temperature anomalies in the NH high latitudes and possible difficulties in isolating an anthropogenic component of climate changes.  相似文献   

6.
Seasonal and interannual variability of surface chlorophyll concentration in the Bering Sea was examined using Empirical Orthogonal Function (EOF) analysis of data obtained by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) from 1998 to 2002. The analysis of normalized monthly fields (removing temporal and spatial monthly means) shows that different temporal and spatial patterns are evident in the eastern and western Bering Sea during the spring bloom period. The first EOF mode explains 30% of the variability and shows how the eastern shelf break region and the western Bering Sea are out of phase during the spring bloom. The second EOF mode (17.6%) indicates a pattern involving the eastern shelf break region and the Kamchatka Basin. This strong east–west signal is linked by both surface winds and light. EOF modes of wind-speed anomalies, derived from Special Sensor Microwave Imager (SSM/I), and photosynthetically active radiance (PAR) from SeaWiFS, show a similar dipole feature where the east–west pattern is related to the position and strength of the Aleutian Low pressure system. In years when the Aleutian Low shifts from west to east, weaker wind stress facilitates the development of stratification resulting in a strong spring bloom in the western Bering Sea. The variability of spring chlorophyll has a strong connection with variability in atmospheric forcing in the Bering Sea.  相似文献   

7.
田永青  潘爱军 《台湾海峡》2012,31(4):540-548
利用OAFLUX气候态月平均热通量资料及TMI云量、降雨、SST和QuikScat风场资料,对南海、特别是巴拉望岛西北海域净热通量的时空特征进行了深入分析.研究发现,夏季在巴拉望岛西北海域存在一局域净热通量极小值区,在7月份该海域海洋甚至呈现失热达20 W/m2情况.分析认为该局地净热通量异常可能与南海暖水的发生、发展有关,即由于西南季风爆发,巴拉望岛西北海域对流加强,一方面,蒸发增大使得潜热增大、云量增多,导致入射太阳短波辐射的减少;另一方面,降水的增大使得该海域出现障碍层现象,障碍层导致的局地海温正反馈进一步增强了局地对流,从而加剧海洋失热过程,促成了巴拉望岛西北海域净热通量局地异常的出现.进一步的经验正交模态（EOF）分析表明,在季节变化尺度上,南海净热通量的第一模态（89.1%）呈同位相变化,反映了南海受冬、夏季风的交替驱动特征;其中南海北部（海南岛至台湾海峡南段的带状海域）为振幅最大区,这与该海域存在年平均最大风速有关;第二模态（10.0%）以吕宋岛至雷州半岛一线为界,南北两侧反相,并具有显著的局域特征;不仅反映了黑潮入侵与南海环流的季节变化,而且还发现巴拉望岛西北海域存在一局地极值域,对应夏季净热通量异常区.  相似文献   

8.
根据南黄海断面1977—2016年历年8月标准层温度、盐度与气候要素观测资料,采用时空分析等方法,分析了南黄海断面夏季温度、盐度年际时空变化与气候响应。断面温度主要有4种时空模态,夏季风生环流、冷水团强度、面积与断面冬季温度模态是主要温度模态年际变化的主要影响因素;夏季风生流场形态、春季PDO指数与断面冬季温度模态是次要温度模态年际变化的主要影响因素;温度模态时间分量均为准平衡态长期变化。断面盐度主要有4种时空模态,夏季苏北沿海低盐度水体、南黄海中部高盐度水体与夏季黄海风生流输送作用是盐度主要模态年际变化的主要影响因素;夏季南黄海降水量减少与风生流输送减弱是盐度次要模态年际变化的主要影响因素。盐度主要模态时间分量为准平衡态长期变化,次要模态时间分量存在显著线性低盐趋势变化。断面夏季温盐多年平均分布主要受到夏季多年平均风生环流影响。断面核心冷水团月平均温度为准平衡态长期变化;面积存在显著线性减小趋势,黄海风生流场季节与年际变化是南黄海核心冷水团年际变化主要影响因素,春季PDO指数对冷水团面积年际变化有显著非线性影响。断面冷水团、核心冷水团月平均盐度为显著线性低盐趋势周期年际变化。由于黄海温盐长期线性趋势变化,与30多年前状况相比,目前黄海温盐场季节循环时空变化形态可能已经发生显著改变。  相似文献   

9.
A long term simulation of the barotropic circulation in the Río de la Plata estuary was performed with the aim of identifying the characteristic patterns of sea surface height (SSH) variability from synoptic to inter-annual time scales and their forcing mechanisms. Hamburg Shelf Ocean Model (HamSOM), forced by tides, monthly mean runoffs and 4-daily 10 m winds and surface atmospheric pressure from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis was run. The solution was analyzed for the period 1965–2004. Inter-annual variability accounts for almost 10% of the variance. The first EOF mode of SSH variability on this time scale is associated with a mean anomaly of approximately 0.25 m at the upper estuary forced by both runoff and winds, which seems to be strongly associated with the ENSO cycles. Other two modes, with periodicities around 2.5 and 10 years were also found. Even though they are linked to weaker SSH anomalies, they are consistent with inter-annual modes of wind variability reported by other authors. Those modes are important, particularly if they act in phase, because they can provide a background for stronger surges. In contrast with the salinity field, SSH variability on seasonal time scales accounts for a very small percentage of variance and it is the combination of an annual and a semi-annual signal forced by winds and runoff, respectively. Approximately 90% of the variance is due to wind driven variability on sub-annual time scales. The most significant SSH anomalies in this band are associated with cyclogenetic events in the atmosphere, occurring either over Uruguay or over the Patagonian Shelf, whereas the strengthening or weakening of the semi-permanent South Atlantic anticyclone displays a relatively smaller influence. In agreement with previous publications, the estuary's spatial patterns in response to short-scale wind variability seem to be determined by wind direction more than by wind speed.  相似文献   

10.
西北太平洋海气界面热通量时空分布特征研究   总被引：2，自引：0，他引：2       下载免费PDF全文
翟方国 《海洋科学》2009,33(7):37-42
基于第三版本HOAPs (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data)海表面温度、潜热通量、感热通量、海表面空气比湿以及海表面风场5个参量的18 a(1988～2005年)逐月平均资料,利用经验正交函数和奇异值分解方法分析了异常潜热和感热通量场在西北太平洋的时空分布特征及造成这种分布的主要影响因素.EOF的分析结果表明,异常潜热通量场主要体现为第一第二两个模态的变化,第一模态显示整个海域呈同相变化且在时间上呈准年周期变化,第二模态则描述了分别位于10°N,25°N和40°N的3个极值中心并伴随多年振荡,由因子载荷分布可知热带太平洋是第二模态的行为中心,因此该模态可能与ENSO事件相关.异常感热通量场则主要表现为第一模态的变化,在时间上呈准年周期变化并伴随有多年时间尺度的振荡.奇异值分解方法的分析结果表明异常海表面风场是异常潜热和感热通量场时空变化的重要影响因素.  相似文献   

11.
热带太平洋障碍层厚度的时空特征分析   总被引：2，自引：0，他引：2  
利用中国Argo实时数据中心提供的9 a(2000—2008年)网格化Argo剖面浮标温、盐数据(G Argo),分析热带太平洋障碍层厚度的气候态分布和低频变化特征。气候平均结果表明,较厚的障碍层主要出现于西太平洋暖池区,并有3条纬向障碍层带状分布,从暖池出发向东延伸至120°W,分别位于以15°N,5°N和12°S为中心的纬度带上。经验正交函数(EOF)基本模态分析表明,热带太平洋障碍层低频振荡以季节和年际变化为主,在季节尺度上主要表现为15°N和12°S障碍层纬度带呈反相变化,都在当地冬季最大,夏季最小;在年际尺度上则主要表现为暖池东边界附近障碍层与厄尔尼诺南方涛动(ENSO)相关的变化,以及暖池中部障碍层与热带准2 a周期振荡(TBO)相关的变化。  相似文献   

12.
To examine the surface circulation and vertical structure of currents in the region of the Keum River (KR) plume, we analyzed the subinertial surface currents obtained by high frequency radar and the vertical profiles of currents measured at a station (M1) located 10 km distance from the estuary mouth for one month in late spring 2008. Monthly-mean surface circulation is composed of the westward flow from the estuary mouth and the northward flow in the offshore. These surface mean currents are a gradient (geostrophic) current around the monthly-mean plume bulge. Dominant variabilities of the surface currents, winds, and KR-outflow are decomposed by the Empirical Orthogonal Functions (EOF). The first current EOF mode, explaining 39% of total variation, is primarily related to the first wind EOF mode varying along the coast and the second current mode, explaining 33% of total variation, is mainly related to the first KR-outflow EOF mode varying along the mean KR-outflow direction. Meanwhile, vertical profile of the monthly-mean current at M1 shows a two-layer structure of the current flowing offshore (onshore) in the upper (lower) layer because the water column is divided by a pycnocline at 7-9 m depths below the plume water. This two layer structure is a background persisting current structure, at least in spring, maintained by the geostrophic balance induced by the sea level slope and density gradient along the line normal to the westward mean surface current direction due to monthly-mean plume bulge off the KR estuary. EOF analysis of vertical current profiles reveals that the first mode, explaining 43% of total variation, represents the two-layer structure of the current variability. The upper-layer current varies along a line normal to the mainland coastline and the low-layer one varies approximately along a line parallel to the coastline, with direction difference of about 115° between the upper-and low-layer. From the correlation analysis it is found that 60% of the first mode variation is influenced by the first mode of KR-outflow and 36% by the first mode of wind. Any forcing modes of KR-outflow and wind influencing the other current vertical modes could not be found in the present study.  相似文献   

13.
Year-long time-series of temperature, salinity and velocity from 12 locations throughout the Chukchi Sea from September 1990 to October 1991 document physical transformations and significant seasonal changes in the throughflow from the Pacific to the Arctic Ocean for one year. In most of the Chukchi, the flow field responds rapidly to the local wind, with high spatial coherence over the basin scale—effectively the ocean takes on the lengthscales of the wind forcing. Although weekly transport variability is very large (ca. -2 to ), the mean flow is northwards, opposed by the mean wind (which is southward), but presumably forced by a sea-level slope between the Pacific and the Arctic, which these data suggest may have significant variability on long (order a year) timescales. The high flow variability yields a significant range of residence times for waters in the Chukchi (i.e. one to six months for half the transit) with the larger values applicable in winter.Temperature and salinity (TS) records show a strong annual cycle of freezing, salinization, freshening and warming, with sizable interannual variability. The largest seasonal variability is seen in the east, where warm, fresh waters escape from the buoyant, coastally trapped Alaskan Coastal Current into the interior Chukchi. In the west, the seasonally present Siberian Coastal Current provides a source of cold, fresh waters and a flow field less linked to the local wind. Cold, dense polynya waters are observed near Cape Lisburne and occasional upwelling events bring lower Arctic Ocean halocline waters to the head of Barrow Canyon. For about half the year, at least at depth, the entire Chukchi is condensed into a small region of TS-space at the freezing temperature, suggesting ventilation occurs to near-bottom, driven by cooling and brine rejection in autumn/winter and by storm-mixing all year.In 1990–1991, the ca. 0.8 Sv annual mean inflow through Bering Strait exits the Chukchi in four outflows—via Long Strait, Herald Valley, the Central Channel, and Barrow Canyon—each outflow being comparable (order 0.1–0.3 Sv) and showing significant changes in volume and water properties (and hence equilibrium depth in the Arctic Ocean) throughout the year. The clearest seasonal cycle in properties and flow is in Herald Valley, where the outflow is only weakly related to the local wind. In this one year, the outflows ventilate above and below (but not in) the Arctic halocline mode of 33.1 psu. A volumetric comparison with Bering Strait indicates significant cooling during transit through the Chukchi, but remarkably little change in salinity, at least in the denser waters. This suggests that, with the exception of (in this year small) polynya events, the salinity cycle in the Chukchi can be considered as being set by the input through Bering Strait and thus, since density is dominated by salinity at these temperatures, Bering Strait salinities are a reasonable predictor of ventilation of the Arctic Ocean.  相似文献   

14.
利用HOAPS资料研究南海海气界面热通量时空分布   总被引：6，自引：3，他引：6  
基于第二版本HOAPS(Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data)潜热、感热和海表温度(SST)3个参量的15 a(1988~2002年)逐月平均资料,利用经验正交方法分解分析了这3个参量在南海的时空分布.结果表明,在夏季模态,潜热表现为南高北低,感热表现为中间低两边高,两者主要都是海洋向大气输送热量,但大气有时也向南海中部输送感热;在冬季模态,潜热和感热的高值区都在南海北部,东北部有一强中心,该中心主要是由风场引起的;夏季SST的变化导致全年SST呈准半年周期变化.冬季SST的变化滞后于潜热变化1个月;除夏季和冬季模态外,冬夏转换季节模态也十分明显;HOAPS与NCEP(National Center of Environment Prediction)资料相比,两者3个参量的时空分布大体一致,区别在于HOAPS资料能更好地反映参量的一些细微特征.  相似文献   

15.
Climate fluctuations, or modes, are largely manifested in terms of coherent, large-scale (3000 km) patterns of anomalous sea-level pressure or geopotential height at various altitudes. It is worthwhile to investigate how these modes relate to the specific processes associated with atmospheric forcing of the ocean, in this case for the southeast Bering Sea. This approach has been termed “downscaling.” Climate-scale patterns in this study are derived from covariance-based empirical orthogonal functions (EOFs) of low-pass filtered (10-day cut-off) 700-mb geopotential height fields for 1958–1999. By design, this EOF analysis elicits sets of patterns for characterizing the variability in the large-scale atmospheric circulation centered on the Bering Sea. Four modes are considered for each of three periods, January–March, April–May, and June–July. These modes are compared with atmospheric circulation patterns formed by compositing 700-mb height anomalies based on the individual elements constituting the local forcing, i.e. the surface heat and momentum fluxes.In general, different aspects of local forcing are associated with different climate modes. In winter, the modes dominating the forcing of sea-ice include considerable interannual variability, but no discernible long-term trends. A prominent shift did occur around 1977 in the sign of a winter mode resembling the Pacific North American pattern; this mode is most significantly related to the local wind-stress curl. In spring, forcing of currents and stratification are related to the two leading climate modes, one resembling the North Pacific (NP) pattern and one reflecting the strength of the Aleutian low; both exhibit long-term trends with implications for the Bering Sea. In summer, an NP-like mode and a mode featuring a center over the Bering Sea include long-term trends with impacts on surface heating and wind mixing, respectively. Rare events, such as a persistent period of strong high pressure or a major storm, also can dominate the summer Bering Sea forcing in particular years.  相似文献   

16.
The Water Framework Directive (2000/60/EC) requires member states to classify and enhance the ecological quality of water bodies in accordance with their type. To estimate the effect on type of the natural variability of lagoons, we applied a two-dimensional hydrodynamic model to the lagoon of Venice. The model calculated the mean annual spatial distributions of two variables: salinity and residence time. The standard deviation of salinity was also included, in order to estimate the variation of salinity values around the mean, which is associated with the instability of the mean salinity value.A highly detailed numerical grid was calibrated and high-frequency tributary discharge data were used.The simulations, under realistic forcing conditions, are based on the years 2003 and 2005. The former was characterized by low precipitation, around 30% less than the typical value.A comparison of model results and measurements shows the high reliability of the model in reproducing the spatial distribution and temporal evolution of salinity.We found strong inter-annual variation in salinity, standard deviation of salinity and residence time. The effect on the typing process is that the most representative types shift from one category to another.On the basis of the spatial patterns of the variables and their superposition, we identified types that described the bulk of the lagoon.This numerical tool offers support for lagoon management on various levels, in terms of both WFD requirements and other applications, by: (1) providing unbiased and objective zoning indications for the basin; (2) evaluating the response of water quality elements; (3) establishing the reference status of a water body; and (4) establishing a hierarchical division of a lagoon that can be used to select an appropriate number of sampling stations for monitoring.  相似文献   

17.
The characteristics of temperature and salinity variation in the Pacific warm pool were investigated using Empirical Orthogonal Function (EOF) analysis on one year's temperature and salinity data in the surface layer (0–50 m) obtained from the Triangle Trans-Ocean Buoy Network (TRITON) buoy array. Two dominant modes of surface temperature and salinity variation were found. One is a positive correlation mode where temperature and salinity were scattered almost parallel to isopycnal lines in a T-S diagram, which has little effect on the density field. The other is a negative correlation mode where temperature and salinity were distributed across isopycnal lines, which has a substantial impact on the density field. In particular, we found that the negative correlation mode at 5°N, 156°E was predominant on a seasonal time scale and contributed to the surface dynamic height variation, and therefore to surface geostrophic current. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
A six-month-long study was conducted of the fate of turbid river plumes from the Enipein watershed in Pohnpei, Federated States of Micronesia. Pohnpei is one of the wettest places on earth, with a mean annual rainfall exceeding 4 m in the lowlands and 8 m in the highlands. The river waters were clear of sediment except after major storms with rainfall exceeding 5 cm day−1. Following a storm, the river plume spread in the mangrove fringed estuary and in the coral reef lagoon. The waters were highly stratified in temperature, salinity, and suspended sediment concentration. The brackish water was flushed out in four days, while the suspended sediment all settled out in the estuary, in the mangroves, and in the lagoon including on the coral reefs, in less than one day. The mean rate of sedimentation exceeded 35 mg cm−2 d−1 both over the mangroves and on the adjacent coral reefs. While this leads to no detrimental effects on the mangroves, sediment smothers corals and leads to substantial coral mortality in the lagoon. The mud is not flushed out from the lagoon because there are no strong currents from waves or tides. This high sedimentation rate is attributable to poor farming and land-use practices on the upland areas.  相似文献   

19.
The relationship between physical forcing and biological response observed in the Arabian Sea for the years 1978–1986 were examined. Spatial and temporal patterns of variability in a climatological time-series of three possible physical forcing parameters and CZCS-derived phytoplankton pigment concentration during the annual cycle were quantified using single and joint empirical orthogonal function (EOF) and singular-value decomposition (SVD) analyses. Monthly composites of the NASA regional pigment data were interpolated to fill data voids and binned corresponding to the physical flux data. Nearly all the spatial-temporal analyses consistently partitioned a large portion of the variability using only 1 or 2 dominant modes and indicated a lag in the timing of the peak pigment concentration behind the maxima in physical forcing. In all cases, major modes of variability resembled the Southwest Monsoon pattern, with the Northeast Monsoon contributing very little to the total variance and covariance. The Joint EOF and SVD analyses incorporated subtle features surrounding the peak Southwest Monsoon phenomena. Correlation maps of the joint EOF analysis depicted differences in spatial variability of pigment concentration associated with stress and curl, showing areas of curl-driven upwelling distinct from coastal upwelling, with possible off-shore advection of the curl-induced high pigment waters.  相似文献   

20.
《Oceanologica Acta》1998,21(2):179-190
The annual cycle of temperature, salinity and nutrients of surface waters (up to 100 m depth) was studied from June 1991 to December 1995 in a cross-shelf section over the continental shelf waters off Santander (southern Bay of Biscay). The time series showed that the temperature followed the expected seasonal warming and cooling pattern, which determines a seasonal process of stratification and mixing of the water column. The stratification period occurs annually between May and October in a layer of about 50 m depth from the neritic station beyond to the shelf-break. In the period between November and April the water column remained mixed. During spring and summer low salinity values were found in the surface due to continental runoff and advection from oceanic waters. In late autumn and winter, the salinity pattern was governed by an influx of salty water associated with the poleward current. As in other temperate latitudes, nitrates showed the highest values in winter throughout the water column and the lowest values at the surface during the stratified period. Wind-induced upwelling events were observed mainly in summer, which are characterised by low temperatures (< 12°C), high salinity and nutrient concentrations. The inter-annual variability of temperature showed a warming trend in the upper layers but this sign was not found at 100 m depth. In salinity a decreasing trend was observed throughout the water column, and this feature corresponds to the relaxing of the high salinity anomaly detected in the North Atlantic at the beginning of the 1990s. Both trends were coherent in the cross-shelf section from the coast to the slope.  相似文献   

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