共查询到19条相似文献，搜索用时 109 毫秒
1.
In the past nearly two decades, the Argo Program has created an unprecedented global observing array with continuous in situ salinity observations, providing opportunities to extend our knowledge on the variability and effects of ocean salinity. In this study, we utilize the Argo data during 2004–2017, together with the satellite observations and a newly released version of ECCO ocean reanalysis, to explore the decadal salinity variability in the Southeast Indian Ocean(SEIO) and its impacts on the regional sea level changes. Both the observations and ECCO reanalysis show that during the Argo era, sea level in the SEIO and the tropical western Pacific experienced a rapid rise in 2005–2013 and a subsequent decline in 2013–2017. Such a decadal phase reversal in sea level could be explained, to a large extent, by the steric sea level variability in the upper 300 m. Argo data further show that, in the SEIO, both the temperature and salinity changes have significant positive contributions to the decadal sea level variations. This is different from much of the Indo-Pacific region, where the halosteric component often has minor or negative contributions to the regional sea level pattern on decadal timescale. The salinity budget analyses based on the ECCO reanalysis indicate that the decadal salinity change in the upper 300 m of SEIO is mainly caused by the horizontal ocean advection. More detailed decomposition reveals that in the SEIO, there exists a strong meridional salinity front between the tropical low-salinity and subtropical high salinity waters. The meridional component of decadal circulation changes will induce strong cross-front salinity exchange and thus the significant regional salinity variations. 相似文献
2.
利用Argo剖面浮标分析上层海洋对台风“布拉万”的响应 总被引：9，自引：2，他引：7
In situ observations from Argo profiling floats combined with satellite retrieved SST and rain rate are used to investigate an upper ocean response to Typhoon Bolaven from 20 through 29 August 2012. After the passage of Typhoon Bolaven, the deepening of mixed layer depth(MLD), and the cooling of mixed layer temperature(MLT) were observed. The changes in mixed layer salinity(MLS) showed an equivalent number of increasing and decreasing because the typhoon-induced salinity changes in the mixed layer were influenced by precipitation, evaporation, turbulent mixing and upwelling of thermocline water. The deepening of the MLD and the cooling of the MLT indicated a significant rightward bias, whereas the MLS was freshened to the left side of the typhoon track and increased on the other side. Intensive temperature and salinity profiles observed by Iridium floats make it possible to view response processes in the upper ocean after the passage of a typhoon. The cooling in the near-surface and the warming in the subsurface were observed by two Iridium floats located to the left side of the cyclonic track during the development stage of the storm, beyond the radius of maximum winds relative to the typhoon center. Water salinity increases at the base of the mixed layer and the top of the thermocline were the most obvious change observed by those two floats. On the right side of the track and near the typhoon center when the typhoon was intensified, the significant cooling from sea surface to a depth of 200×104 Pa, with the exception of the water at the top of the thermocline, was observed by the other Iridium float. Owing to the enhanced upwelling near the typhoon center, the water salinity in the near-surface increased noticeably. The heat pumping from the mixed layer into the thermocline induced by downwelling and the upwelling induced by the positive wind stress curl are the main causes for the different temperature and salinity variations on the different sides of the track. It seems that more time is required for the anomalies in the subsurface to be restored to pretyphoon conditions than for the anomalies in the mixed layer. 相似文献
3.
Combined conductivity-temperature-depth(CTD) casts and Argo profiles, 3 086 historical hydrocasts were used to quantify the water column characteristics in the northern South China Sea(SCS) and its adjacent waters. Based on a two-dimensional "gravest empirical mode"(GEM), a gravitational potential(, a vertically integrated variable) was used as proxy for the vertical temperature profiles TG(p,). integrated from 8 MPa to the surface shows a close relationship with the temperature, except in the deep layer greater than 15 MPa, which was caused by the bimodal deep water in the region. The GEM temperature profiles successfully revealed the bimodality of the Luzon Strait deep water, that disparate hydrophic vertical profiles can produce distinct specific volume anomaly() in the SCS and the western Philippine Sea(WPS), but failed in the Luzon Strait, where different temperature profiles may produce a same. A significant temperature divergence between the SCS water and the WPS water confirmed that the bimodal structure is strong. The deepwater bifurcation starts at about 15 MPa, and gets stronger with increasing depth. As the only deep channel connecting the bimodal-structure waters, water column characteristics in the Luzon Strait is in between, but much closer to the SCS water because of its better connectivity with the SCS. A bimodal temperature structure below 15 MPa reveals that there was a persistent baroclinic pressure gradient driving flow through the Luzon Strait. A volume flux predicted through the Bashi Channel with the hydraulic theory yields a value of 5.62×106 m3/s using all available profiles upstream and downstream of the overflow region, and 4.03×106and 2.70×106 m3/s by exclusively using the profiles collected during spring and summer, respectively. No volume flux was calculated during autumn and winter because profiles are only available for the upstream of the Bashi Channel during the corresponding period. 相似文献
4.
关于南海北部上层水团的分类及三维分布的研究 总被引：2，自引：1，他引：1
Using the fuzzy cluster analysis and the temperature-salinity(T-S) similarity number analysis of cruise conductivity-temperature-depth(CTD) data in the upper layer(0–300 m) of the northern South China Sea(NSCS), we classify the upper layer water of the NSCS into six water masses: diluted water(D), surface water(SS),the SCS subsurface water mass(U_S), the Pacific Ocean subsurface water mass(U_P), surface-subsurface mixed water(SU) and subsurface-intermediate mixed water(UI). A new stacked stereogram is used to illustrate the water mass distribution, and to examine the source and the distribution of U_P, combining with the sea surface height data and geostrophic current field. The results show that water mass U_P exists in all four seasons with the maximum range in spring and the minimum range in summer. In spring and winter, the U_P intrudes into the Luzon Strait and the southwest of Taiwan Island via the northern Luzon Strait in the form of nonlinear Rossby eddies, and forms a high temperature and high salinity zone east of the Dongsha Islands. In summer, the U_P is sporadically distributed in the study area. In autumn, the U_P is located in the upper 200 m layer east of Hainan Island. 相似文献
5.
Understanding of the temporal variation of oceanic heat content(OHC) is of fundamental importance to the prediction of climate change and associated global meteorological phenomena. However, OHC characteristics in the Pacific and Indian oceans are not well understood. Based on in situ ocean temperature and salinity profiles mainly from the Argo program, we estimated the upper layer(0–750 m) OHC in the Indo-Pacific Ocean(40°S–40°N, 30°E–80°W). Spatial and temporal variability of OHC and its likely physical mechanisms are also analyzed. Climatic distributions of upper-layer OHC in the Indian and Pacific oceans have a similar saddle pattern in the subtropics, and the highest OHC value was in the northern Arabian Sea. However, OHC variabilities in the two oceans were different. OHC in the Pacific has an east-west see-saw pattern, which does not appear in the Indian Ocean. In the Indian Ocean, the largest change was around 10°S. The most interesting phenomenon is that, there was a long-term shift of OHC in the Indo-Pacific Ocean during 2001–2012. Such variation coincided with modulation of subsurface temperature/salinity. During 2001–2007, there was subsurface cooling(freshening)nearly the entire upper 400 m layer in the western Pacific and warming(salting) in the eastern Pacific. During2008–2012, the thermocline deepened in the western Pacific but shoaled in the east. In the Indian Ocean, there was only cooling(upper 150 m only) and freshening(almost the entire upper 400 m) during 2001–2007. The thermocline deepened during 2008–2012 in the Indian Ocean. Such change appeared from the equator to off the equator and even to the subtropics(about 20°N/S) in the two oceans. This long-term change of subsurface temperature/salinity may have been caused by change of the wind field over the two oceans during 2001–2012, in turn modifying OHC. 相似文献
6.
In this study, we develop a variable-grid global ocean general circulation model(OGCM) with a fine grid(1/6)°covering the area from 20°S–50°N and from 99°–150°E, and use the model to investigate the isopycnal surface circulation in the South China Sea(SCS). The simulated results show four layer structures in vertical: the surface and subsurface circulation of the SCS are characterized by the monsoon driven circulation, with basin-scaled cyclonic gyre in winter and anti-cyclonic gyre in summer. The intermediate layer circulation is opposite to the upper layer, showing anti-cyclonic gyre in winter but cyclonic gyre in summer. The circulation in the deep layer is much weaker in spring and summer, with the maximum velocity speed below 0.6 cm/s. In fall and winter, the SCS deep layer circulation shows strong east boundary current along the west coast of Philippine with the velocity speed at 1.5 m/s, which flows southward in fall and northward in winter. The results have also revealed a fourlayer vertical structure of water exchange through the Luzon Strait. The dynamics of the intermediate and deep circulation are attributed to the monsoon driving and the Luzon Strait transport forcing. 相似文献
7.
盐度对变化2014年东北太平洋“暖泡”的作用 总被引：1，自引：0，他引：1
A significant strong, warm "Blob"(a large circular water body with a positive ocean temperature anomaly)appeared in the Northeast Pacific(NEP) in the boreal winter of 2013–2014, which induced many extreme climate events in the US and Canada. In this study, analyses of the temperature and salinity anomaly variations from the Array for Real-time Geostrophic Oceanography(Argo) data provided insights into the formation of the warm"Blob" over the NEP. The early negative salinity anomaly dominantly contributed to the shallower mixed layer depth(MLD) in the NEP during the period of 2012–2013. Then, the shallower mixed layer trapped more heat in the upper water column and resulted in a warmer sea surface temperature(SST), which enhanced the warm"Blob". The salinity variability contributed to approximately 60% of the shallowing MLD related to the warm"Blob". The salinity anomaly in the warm "Blob" region resulted from a combination of both local and nonlocal effects. The freshened water at the surface played a local role in the MLD anomaly. Interestingly, the MLD anomaly was more dependent on the local subsurface salinity anomaly in the 100–150 m depth range in the NEP.The salinity anomaly in the 50–100 m depth range may be linked to the anomaly in the 100–150 m depth range by vertical advection or mixing. The salinity anomaly in the 100–150 m depth range resulted from the eastward transportation of a subducted water mass that was freshened west of the dateline, which played a nonlocal role.The results suggest that the early salinity anomaly in the NEP related to the warm "Blob" may be a precursor signal of interannual and interdecadal variabilities. 相似文献
8.
《海洋学报(英文版)》2019,(9)
A significant strong, warm "Blob"(a large circular water body with a positive ocean temperature anomaly)appeared in the Northeast Pacific(NEP) in the boreal winter of 2013–2014, which induced many extreme climate events in the US and Canada. In this study, analyses of the temperature and salinity anomaly variations from the Array for Real-time Geostrophic Oceanography(Argo) data provided insights into the formation of the warm"Blob" over the NEP. The early negative salinity anomaly dominantly contributed to the shallower mixed layer depth(MLD) in the NEP during the period of 2012–2013. Then, the shallower mixed layer trapped more heat in the upper water column and resulted in a warmer sea surface temperature(SST), which enhanced the warm"Blob". The salinity variability contributed to approximately 60% of the shallowing MLD related to the warm"Blob". The salinity anomaly in the warm "Blob" region resulted from a combination of both local and nonlocal effects. The freshened water at the surface played a local role in the MLD anomaly. Interestingly, the MLD anomaly was more dependent on the local subsurface salinity anomaly in the 100–150 m depth range in the NEP.The salinity anomaly in the 50–100 m depth range may be linked to the anomaly in the 100–150 m depth range by vertical advection or mixing. The salinity anomaly in the 100–150 m depth range resulted from the eastward transportation of a subducted water mass that was freshened west of the dateline, which played a nonlocal role.The results suggest that the early salinity anomaly in the NEP related to the warm "Blob" may be a precursor signal of interannual and interdecadal variabilities. 相似文献
9.
Hui Chen Shuang Li Hailun He Jinbao Song Zheng Ling Anzhou Cao Zhongshui Zou Wenli Qiao 《海洋学报(英文版)》2021,40(1):70-84
The present work describes the basic features of super typhoon Meranti(2016) by multiple data sources. We mainly focus on the upper ocean response to Meranti using multiplatform satellites, in situ surface drifter and Argo floats, and compare the results with the widely used idealized wind vortex model and reanalysis datasets.The pre-existing meso-scale eddy provided a favor underlying surface boundary condition and also modulated the upper ocean response to Meranti. Results show that the maximum sea surface cooling was 2.0℃ after Meranti.The satellite surface wind failed to capture the core structure of Meranti as the idealized wind vortex model deduced. According to the observation of sea surface drifters, the near-inertial currents were significantly enhanced during the passage of Meranti. The temperature and salinity profiles from Argo floats revealed both the mixed-layer extension and subsurface upwelling induced by Meranti. The comparison results show that the sea surface temperature and surface wind in the reanalysis datasets differs from those in remote sensing system. Sea surface cooling is similar in both satellite and in situ observation, and sea surface salinity response has a lower correlation with the precipitation rate. 相似文献
10.
夏季台湾海峡水及黑潮次表层涌升水向东海近陆架区营养盐输送通量的估算 总被引：2，自引：1，他引：1
According to historical mean ocean current data through the field observations of the Taiwan Ocean Research Institute during 1991–2005 and survey data of nutrients on the continental shelf of the East China Sea(ECS) in the summer of 2006, nutrient fluxes from the Taiwan Strait and Kuroshio subsurface waters are estimated using a grid interpolation method, which both are the sources of the Taiwan Warm Current. The nutrient fluxes of the two water masses are also compared. The results show that phosphate(PO4-P), silicate(SiO3-Si) and nitrate(NO3-N) fluxes to the ECS continental shelf from the Kuroshio upwelling water are slightly higher than those from the Taiwan Strait water in the summer of 2006. In contrast, owing to its lower velocity, the nutrient flux density(i.e., nutrient fluxes divided by the area of the specific section) of the Kuroshio subsurface water is lower than that of the Taiwan Strait water. In addition, the Taiwan Warm Current deep water, which is mainly constituted by the Kuroshio subsurface water, might directly reach the areas of high-frequency harmful alga blooms in the ECS. 相似文献
11.
南海是西北太平洋最大的边缘海, 是联系北太平洋和北印度洋的关键通道。黑潮北上经过吕宋海峡时会将来自西太平洋的信号传入南海, 进而影响南海的水动力环境。研究了南海次表层盐度的空间分布特征、低频变化规律及其与太平洋年代际振荡(Pacific Decadal Oscillation, PDO)的关系, 并进一步探究了次表层盐度近年来的变化。结果显示: 1)南海次表层高盐水的位势密度主要介于24~26σθ, 受次表层气旋式环流所驱动, 盐度气候态空间分布北高南低, 以吕宋海峡处为起点, 呈逆时针自北向南逐渐降低。2)次表层盐度低频变化显著, 与PDO呈显著的正相关关系。当PDO处于正位相时, 吕宋海峡处西向平流输送加强, 次表层盐度升高; 当PDO处于负位相时, 吕宋海峡处西向平流输送减弱, 次表层盐度降低, 盐度的变化受到水平环流场的直接影响。3)近年来, 南海次表层盐度呈现先降低后升高再降低的趋势, 滞后PDO约10个月, 2006— 2014年初, 盐度呈下降趋势; 2014—2017年初, 盐度呈上升趋势, 且上升速率远大于先前下降的速率; 2017年后盐度再次逐渐降低。 相似文献
12.
1998年春夏南海温盐结构及其变化特征 总被引：11，自引：2，他引：11
利用1998年5～8月“南海季风试验”期间“科学1”号和“实验3”号科学考察船两个航次CTD资料,分析了1998年南海夏季风暴发前后南海主要断面的温盐结构及其变化特征.观测发现,南海腹地基本被典型的南海水团所控制,但在南海东北部尤其是吕宋海峡附近,表层和次表层水明显受到西太平洋水的影响.季风暴发以后,南海北部表面温度有显著升高,升幅由西向东递减,而南海中部和南部表面温度基本没变,这使得南海北部东西向温度梯度和整个海盆南北向温度梯度均减小.北部断面表层盐度普遍由34以上降低到34以下,混合层均有所发展,是季风暴发后降水和风力加剧的结果.观测期间黑潮水跨越吕宋海峡的迹象明显但变化剧烈.4～5月,黑潮次表层水除在吕宋海峡中北部出现外,在吕宋岛以西亦有发现,表明有部分黑潮水从吕宋海峡南端沿岸向西进而向南进入南海.6～7月,次表层高盐核在吕宋海峡中北部有极大发展,但在吕宋岛以西却明显萎缩;虽然看上去黑潮水以更强的流速进、出南海,但对南海腹地动力热力结构的影响未必更大.一个超过34.55的表层高盐水体于巴拉望附近被发现,似与通过巴拉望两侧水道入侵南海的西太平洋水有关. 相似文献
13.
利用Argo浮标资料分析横跨吕宋海峡20.5°N断面的水文特征 总被引：2，自引：0，他引：2
基于Argo浮标资料,分析了一条横跨南海北部、吕宋海峡和西太平洋（20.5°N,114°~130°E）断面的海水温度、盐度的分布特征.其结果表明：Argo剖面资料得到的2008年秋季20.5°N断面海水的温度、盐度分布态势与气候态秋季的分布基本一致,主要差异在于南海次表层水的盐度极大值和西太平洋次表层水的盐度极大值,2008年秋季二者均比气候态秋季的低0.1左右.通过动力计算（选取1 200 m为速度零面）表明：Argo浮标剖面资料与融合的卫星高度计产品得到的20.5°N,117.5°~124.5°E断面的表层地转流北分量的分布比较吻合;吕宋海峡中部（20°~21°N）的黑潮主轴大致位于121.5°E附近,其东边界可达123°E,而西边界仅限于121°E以西,其可能原因是该季节黑潮的左侧存在着一个气旋式环流,阻碍了黑潮西进;黑潮在20.5°N断面的体积流量为27×106m3/s左右,最大流速约为55 cm/s,出现在70 m层左右. 相似文献
14.
印尼贯穿流源区马鲁古海和哈马黑拉海水团来源的气候态分析 总被引：3，自引：1，他引：2
本文利用World Ocean Atlas 2013（WOA2013）气候态的温盐资料和the Simple Ocean Data Assimilation （SODA v3.3.1）流场数据，分析印尼贯穿流东部源区马鲁古海和哈马黑拉海的水团垂向分布特征及其来源，特别是次表层、中层及深层水的来源和路径。结果表明，气候态下，马鲁古海次表层的高温高盐水来自于北太平洋，与北太平洋热带水性质接近，哈马黑拉海次表层主要是来自南太平洋热带水；中层水以低温低盐为特征，马鲁古海的中层水来自南太平洋，受南极中层水控制，哈马黑拉海的中层水可能是从马鲁古海而来的南太平洋水；对于次表层和中层之间的过渡层，马鲁古海与哈马黑拉海的水源为南、北太平洋的混合水，且两个海域之间也存在着水团交换；在深层，马鲁古海的水源更倾向于班达海北部及塞兰海，而与太平洋水无关，哈马黑拉海由于地形阻挡也难以与太平洋直接发生水团交换。 相似文献
15.
南海北部春季非水华期的CO_2分压及其调控 总被引：1，自引：0，他引：1
针对南海北部和吕宋海峡附近海域的海-气CO2通量及其调控问题,研究了2009年3月底至4月中旬在这些海域通过走航观测的方法取得的海-气CO2分压和海表温度、盐度等相关数据。结果表明,在河口、沿岸流以外的南海北部开阔海域,与大气平衡的CO2分压分布在368~380μatm,南低北高,平均值为371μatm;而海表CO2分压分布在293~405μatm,南高北低。南海北部开阔海域的海表CO2分压主要受温度效应调控,也在一定程度上受水团混合、海-气交换、生物活动等非温度效应的影响。在相同水温条件下,黑潮区的海表CO2分压比南海北部的海表CO2分压低。本研究和大多数前人研究的结果都表明,南海北部海盆区域和吕宋海峡西侧海域在春季与大气CO2接近源汇平衡,而非大气CO2的显著源区。 相似文献
16.
利用2006年Argo浮标资料分析吕宋海峡以东海域水团季节特性和混合层的月平均变化规律;并分别利用Argo多年季节平均资料与2006年资料,以秋季为例,基于P矢量方法计算该区域流场;同时考虑风生流的影响,将所得结果分别与利用Levitus和高度计资料计算的流场进行比较。结果表明,水团特性季节变化不明显,春冬季表层水团与夏秋季比较表现为低温高盐;次表层、中层和深层季节变化不大;混合层深度明显表现为冬季最深、夏季最浅的季节性变化。利用2002—2009年Argo季节平均资料基于P矢量方法能得到地转流场的基本结构,与Levitus资料的计算结果相比较,除可以反映黑潮,还可以反映一些涡旋结构;利用2006年秋季Argo资料计算流场与高度计资料计算的地转流场比较,其流场结构位置吻合得比较好,但存在流速偏小等不足,这可能与Argo资料较少且分布不均以及插值误差等有关,但其可以获得流场的三维结构,而利用高度计资料计算只能得到表层流场结构。 相似文献
17.
基于Argo历史观测的南海海盆尺度中层流场研究 总被引：1，自引：0，他引：1
针对南海海域海流环境复杂、中层实测数据量少的现状，本文基于2006-2016年布放在南海海域的114个Argo剖面浮标的卫星定位等信息，采用基于背景流和惯性流外推的最小二乘方法，获取南海海域1 200 m深中层流场信息，并采用Divand变分插值的方法形成网格化季节流场。结果表明:（1）针对南海中层（1 200 m）流场，单个Argo浮标可以刻画出具体的中尺度结构，如越南沿岸的反气旋涡，半径约为120 km，最大流速约为9.6 cm/s，平均流速为5.3 cm/s；（2） Argo网格化流场表明海盆尺度中层流场南海南部为反气旋环流结构，北部为气旋式环流，同时在吕宋海峡口存在从南海至太平洋的水体交换；（3）将该流场信息与HYCOM和YoMaHa'07两种资料对比，吻合度较高，与HYCOM再分析资料的偏差分布趋近于正态分布，海流的东西向分量的均方根误差为3.28 cm/s，南北向分量的均方根误差为3.26 cm/s。总体而言，利用Argo轨迹资料能够有效地反演出南海地区海盆尺度的中层环流特征。 相似文献
18.
Lingling Xie Jiwei Tian Shuwen Zhang Yanwei Zhang Qingxuan Yang 《Journal of Oceanography》2011,67(1):37-46
The complicated flow pattern in the intermediate layer of the Luzon Strait could directly affect the efficiency of the water
and energy exchange between the South China Sea (SCS) and the North Pacific. Here we present a subsurface anticyclonic eddy
in the Luzon Strait deduced using observations conducted in October 2005. On the basis of the hydrographic and current measurements,
an anticyclonic eddy was found in the intermediate layer, i.e., about 26.8–27.3σθ, 500–900 m. It captures part of the SCS Intermediate Water outflow in the northern Luzon Strait, and carries it to flow southward
and then westward back into the SCS in the southern Luzon Strait, with volume transport of about 1.9 × 106 m3 s−1. The simulated results from Hybrid Coordinate Ocean Model also suggest the existence of this anticyclonic eddy that develops
and lingers for a month long. 相似文献
19.
基于中国Argo实时资料中心发布的2004年1月至2017年12月Argo全球温盐资料,运用直线定位法和隶属关系,对吕宋岛以东海域(120°~140°E,10°~30°N)水团进行分析,划分出北太平洋次表层水团(NPSSW)和北太平洋中层水团(NPIW)的分布范围。次表层水团位于50~220 m深度,分布在10°~28°N范围内,温度16.61~27.60℃,盐度34.68~35.14,核心范围春夏季较大,秋冬季较小。中层水团位于280~900 m深度,分布在10~30°N范围内,温度3.67~16.55℃,盐度34.11~34.67,核心范围季节变化较弱,整体位于18°N以北。次表层与中层水团核心温盐具有一定的年际变化特征,次表层水团与气候变化相关性较好,核心温度和盐度均存在4 a的变化周期;而中层水团与气候变化相关性较差,核心温度和盐度则分别具有3.5 a和3 a的变化周期。 相似文献