A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler（SADCP） and three 40 d long bottom-mounted ADCPs（BADCPs） is employed to reveal the spatiotemporal variability of tidal...A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler（SADCP） and three 40 d long bottom-mounted ADCPs（BADCPs） is employed to reveal the spatiotemporal variability of tidal and subtidal currents in the western Taiwan Strait（TWS） during winter season. The results confirm the existence of intense cotidal lines for M2 tidal current, which is located north of 25°N. In this case, no existence of an amphidromic point can be identified. It is also revealed that the counter-wind current（CWC） can extend through the whole western TWS and even occupy the entire water column during winter monsoon relaxation. However,this CWC is observed to be thoroughly overwhelmed by the downwind China coastal current（CCC） during the two big monsoon bloom events in the winter of 2007, and the CCC consequently extends southward throughout the western TWS instead. Most importantly, the variation of the spatial extent for the CWC and the CCC in the western TWS is found to be well explained by the first two modes of the vector empirical orthogonal function（VEOF） analysis, that is, it is mainly controlled by a wind-driven quasi barotropic current as the first mode and slightly modulated by a relatively weak background current with a first-order baroclinic structure as the second mode.展开更多
A three-dimensional （3-D） finite volume coastal ocean model （FVCOM） was used for the study of water cir culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open bound...A three-dimensional （3-D） finite volume coastal ocean model （FVCOM） was used for the study of water cir culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open boundary and discharge from six rivers was included in the numerical calculation. The M2 tidal elevation produced by the FVCOM has a good agreement with the observation data. The M2 tidal current is also suc cessfully calculated under the ebb tide and flood tide conditions. The non-linear M2 tidal residual current was produced by the coastline geometry, especially surrounding the narrow strait between the Serangan Is- land and the Benoa Peninsula. The tidal residual current also generated two small eddies within the bay and one small eddy in the bay mouth. The salinity distribution influenced by river discharge could be success- fully calculated, where the numerical calculation and the observation results have a good correlation （r2） of 0.75. Finally in order to examine the seawater exchange in the Benoa Bay, the Lagrangian particle tracking method and calculation of residence time are applied. The mechanism of particle transport to the flushing of seawater is depicted clearly by both methods.展开更多
文章采用国内外普遍适用于船载声学多普勒流速剖面仪(shipboard acoustic doppler current profilers,SADCP)数据滤潮处理的时空拟合最小二乘法(简称最小二乘法),对台湾海峡南部浅滩2004—2013年夏季(6—9月)所获取的SADCP数据进行正压...文章采用国内外普遍适用于船载声学多普勒流速剖面仪(shipboard acoustic doppler current profilers,SADCP)数据滤潮处理的时空拟合最小二乘法(简称最小二乘法),对台湾海峡南部浅滩2004—2013年夏季(6—9月)所获取的SADCP数据进行正压潮、流分离。结果表明:最小二乘法获得的平均流和基于原始数据格点化后矢量平均取得的平均流流向均趋于东北向,并且具有大致相同的强、弱流区空间分布形态,但最大流速稍有差异,分别为0.48m×s^(-1)和0.36m×s^(-1);此外,强流区(流速~0.3m×s^(-1))流幅狭窄,流轴分别约束在东山至龙海外海30m等深线附近和台湾浅滩南部地形骤变区域;而弱流区(流速<0.1cm×s^(-1))集中分布于台湾浅滩中部。进一步研究表明,2种平均流所估算的海流通量的计算结果比较接近,可达到(0.74±0.25)×10~6m^3·s^(-1)。SADCP数据分离所得M_2分潮流显示:台湾浅滩至东山一线为强潮区,最大可能流速出现在台湾浅滩(约0.67m×s^(-1));等潮时线分布符合前进波特征,在潮波传导方向上由西南向东北依次推迟(约2h);东山近海存在一条呈NW—SE走向的椭圆率正负分界线,分界线以南潮流椭圆顺时针旋转,以北则逆时针旋转。展开更多
基金The National Natural Science Foundation of China under contract Nos 41506014,41306027 and 41276034the Scientific Research Foundation of Third Institute of Oceanography,State Oceanic Administration under contract No.2017011+1 种基金the State Oceanic Administration Program on Global Change and Air-Sea Interactions under contract Nos GASI-IPOVAI-02,GASIIPOVAI-03 and GASI-03-01-01-04the Chinese Academy of Sciences Strategic Leading Science and Technology Projects under contract No.XDA1102030104
文摘A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler（SADCP） and three 40 d long bottom-mounted ADCPs（BADCPs） is employed to reveal the spatiotemporal variability of tidal and subtidal currents in the western Taiwan Strait（TWS） during winter season. The results confirm the existence of intense cotidal lines for M2 tidal current, which is located north of 25°N. In this case, no existence of an amphidromic point can be identified. It is also revealed that the counter-wind current（CWC） can extend through the whole western TWS and even occupy the entire water column during winter monsoon relaxation. However,this CWC is observed to be thoroughly overwhelmed by the downwind China coastal current（CCC） during the two big monsoon bloom events in the winter of 2007, and the CCC consequently extends southward throughout the western TWS instead. Most importantly, the variation of the spatial extent for the CWC and the CCC in the western TWS is found to be well explained by the first two modes of the vector empirical orthogonal function（VEOF） analysis, that is, it is mainly controlled by a wind-driven quasi barotropic current as the first mode and slightly modulated by a relatively weak background current with a first-order baroclinic structure as the second mode.
基金The Beasiswa Unggulan program from Ministry of Education and Cultural Republic of Indonesia
文摘A three-dimensional （3-D） finite volume coastal ocean model （FVCOM） was used for the study of water cir culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open boundary and discharge from six rivers was included in the numerical calculation. The M2 tidal elevation produced by the FVCOM has a good agreement with the observation data. The M2 tidal current is also suc cessfully calculated under the ebb tide and flood tide conditions. The non-linear M2 tidal residual current was produced by the coastline geometry, especially surrounding the narrow strait between the Serangan Is- land and the Benoa Peninsula. The tidal residual current also generated two small eddies within the bay and one small eddy in the bay mouth. The salinity distribution influenced by river discharge could be success- fully calculated, where the numerical calculation and the observation results have a good correlation （r2） of 0.75. Finally in order to examine the seawater exchange in the Benoa Bay, the Lagrangian particle tracking method and calculation of residence time are applied. The mechanism of particle transport to the flushing of seawater is depicted clearly by both methods.
文摘文章采用国内外普遍适用于船载声学多普勒流速剖面仪(shipboard acoustic doppler current profilers,SADCP)数据滤潮处理的时空拟合最小二乘法(简称最小二乘法),对台湾海峡南部浅滩2004—2013年夏季(6—9月)所获取的SADCP数据进行正压潮、流分离。结果表明:最小二乘法获得的平均流和基于原始数据格点化后矢量平均取得的平均流流向均趋于东北向,并且具有大致相同的强、弱流区空间分布形态,但最大流速稍有差异,分别为0.48m×s^(-1)和0.36m×s^(-1);此外,强流区(流速~0.3m×s^(-1))流幅狭窄,流轴分别约束在东山至龙海外海30m等深线附近和台湾浅滩南部地形骤变区域;而弱流区(流速<0.1cm×s^(-1))集中分布于台湾浅滩中部。进一步研究表明,2种平均流所估算的海流通量的计算结果比较接近,可达到(0.74±0.25)×10~6m^3·s^(-1)。SADCP数据分离所得M_2分潮流显示:台湾浅滩至东山一线为强潮区,最大可能流速出现在台湾浅滩(约0.67m×s^(-1));等潮时线分布符合前进波特征,在潮波传导方向上由西南向东北依次推迟(约2h);东山近海存在一条呈NW—SE走向的椭圆率正负分界线,分界线以南潮流椭圆顺时针旋转,以北则逆时针旋转。
