Mediterranean Sea level trends from long-period tide gauge time series     

Mahdi Hadd  Hebib Taibi 《海洋学报(英文版)》2020,39(1):157-165

The main purpose of this study is to highlight， on the basis of statistical tests， the significant long-term changes of the Mediterranean Sea level， through the analysis of historical tide gauge records. In this framework， 14 tide gauge monthly series selected from the Permanent Service of the Mean Sea Level （PSMSL） database were used. The search for the presence or not of trends within these series， that have a temporal coverage from 59 to 142 years， was carried out using the Mann-Kendall test and the Sen''s slope estimator. The obtained results show that the Split Rt Marjana series are the only ones which does not exhibit a significant trend. The other 13 series show significant increasing trends. This result seems sufficient to suppose the presence， in the past century， of a new climatic phase on the scale of the Mediterranean basin， where the rising sea level is one of the consequences.  相似文献   

基于局部时间步长方法的潮流数值模型研究及应用   总被引：1，自引：1，他引：0  

胡鹏  姬奥飞  陶俊余 《海洋工程》2020,38(1):111-119

为了准确快速地模拟潮流过程,将局部时间步长(LTS)方法应用于基于黎曼近似解通量——有限体积法的浅水模型。LTS方法和传统整体最小时间步长方法的计算性能对比表明,两种方法的计算结果定量差异远小于模拟值与实测值之间相对误差;但由于LTS方法对每个网格采用了与稳定性条件相适应的尽可能大的时间步长,计算效率大幅度提高。本模型计算所得渤海、黄海、东海的潮流传播过程、潮汐调和常数的空间分布、无潮点位置,以及长江口和杭州湾区域的潮流过程与已有认识和实测资料吻合良好。  相似文献   

Beach morphodynamic characteristics and classifications on the straight coastal sectors in the west Guangdong     

Ding  Yuanting  Yu  Jitao  Cheng  Huangxin 《地理学报(英文版)》2020,30(7):1179-1194

Journal of Geographical Sciences - Currently beach morphodynamic classification is the most important foundation to conduct associated coastal geomorphological studies. This paper carried out beach...  相似文献   

粤港澳大湾区传统农业洪潮适应开发模式与生态文明经验     

周晴  赵玲玲  吴康敏  李苑君 《热带地理》2019,39(5):701-710

通过梳理17世纪以来至20世纪50年代粤港澳大湾区适应洪涝环境的地域开发典型模式,发现该地区根据洪水和潮水不同作用特点形成3种模式：1）北部肇庆、高要、清远、三水一带的低塱地区,以洪水影响为主,利用西江洪水期旺发的鱼苗资源进行涡塘养殖,发展种植耐涝的深水稻和经济水生植物;2）中部南海、顺德、高明洪潮叠加区普遍开发为连片桑基鱼塘,发展一套防洪抗涝与利用洪水期潮水排灌的技术体系;3）中山、番禺、东莞、新会一带的沿海口门区以潮水作用为主,当地通过沿岸浅滩大量投石修筑小型丁坝、种植水草等技术措施加速滩涂泥沙淤积,围、垦开发。滩涂开发过程中创造性地利用洪潮加速潮滩植物群落演替,以及排灌、改良培肥水稻土、选种适生作物。这3种开发模式是粤港澳大湾区在地域开发中变害为利的具体实践,总结其人水和谐的经验,可为粤港澳大湾区生态文明建设提供借鉴。  相似文献   

Temperature variability caused by internal tides in the coastal waters of east coast of Peninsular Malaysia     

ROSELI Nur Hidayah  AKHIR Mohd Fadzil 《海洋学报(英文版)》2019,38(1):22-31

The effects of tidal currents (i.e., barotropic and internal tides) are important in the biogeochemistry of a coastal shelf sea. The high-frequency of currents and near-bottom temperatures collected in three consecutive southwest monsoon seasons (May, June, July and August of 2013 until 2015) is presented to reveal the role of the tidal currents to the temperature variability in the coastal shelf sea of the east coast of Peninsular Malaysia (ECPM), south of the South China Sea (SCS). The results of a spectral density and harmonic analysis demonstrate that the near-bottom temperature variability and the tidal currents are influenced by diurnal (O₁ and K₁) and semidiurnal (M₂) tidal currents. The spectral density of residual currents (detided data) at 5, 10 and 16 m depth also shows significant peaks at the diurnal tidal frequency (K₁) and small peaks at the semidiurnal tidal frequency (M₂) indicating the existence of internal tides. The result of the horizontal kinetic energy (HKE) shows a strong intermittent energy of internal tides in the ECPM with the strongest energy is found at 16 m depth during a sporadic cooling event in June and July. A high horizontal cross-shore heat flux (16 m) also indicates strong intrusions of cooler water into the ECPM in June and July. During the short duration of cold pulse water observed in June and July, a cross-wavelet analysis also reveals the strong relationship between the near-bottom temperatures and the internal tidal currents at the diurnal tidal frequency. The intrusion of this cooler water is probably related to the monsoon-induced upwelling in June. It is loosely interpreted that the interaction between the strong barotropic tides and the steep slope in the central basin of the SCS under the stratified condition in southwest monsoon has generated these internal tides. The dissipation of internal tides from the slope area probably has driven the cold-upwelled water into the ECPM coastal shelf sea when the upwelling intensity is the highest in June and July.  相似文献   

海南岛西岸上升流对波浪混合的敏感性研究     

白鹏  杨婧灵  张书文  谢玲玲  吴俊杉 《海洋学报(英文版)》2019,38(11):11-19

The coupled ocean–atmosphere–wave–sediment transport(COAWST) modeling system is employed to investigate the role of wave-mixing playing in the upwelling off the west coast of Hainan Island(WHU). Waves,tides and sea surface temperature(SST) are reproduced reasonably well by the model when validated by observations. Model results suggest the WHU is tidally driven. Further investigations indicate that inclusion of wave-mixing promotes the intensity of the WHU, making the simulated SST become more consistent with remote-sensed ones. Dynamically, wave-mixing facilitates the "outcrop" of more upwelled cold water, triggering stronger WHU and leading to a three-dimensional dynamical adjustment. From the perspective of time, wavemixing contributes to establishing an earlier tidal mixing front strong enough to generate WHU and that is, WHU may occur earlier when taking wave-mixing into consideration.  相似文献   

内潮耗散与自吸-负荷潮对南海潮波影响的数值研究   总被引：1，自引：0，他引：1  

姜锦东  方国洪  滕飞  徐晓庆 《海洋与湖沼》2018,49(3):457-470

利用非结构三角形网格的FVCOM海洋数值模式,在其传统二维潮波方程中加入参数化的内潮耗散项和自吸-负荷潮项,计算了南海及其周边海域的M_2、S_2、K_1和O_1分潮的分布。与实测值的比较表明,引入这两项对模拟准确度的提高有明显效果。根据模式结果本文计算分析了研究海域的潮能输入和耗散。能量输入计算表明,能通量是潮能输入的最主要构成部分,通过吕宋海峡断面进入南海的M_2和K_1分潮能通量分别为38和29GW;半日周期的自吸-负荷潮能量输入以负值居多,而全日周期的自吸-负荷潮能量输入以正值居多,因而自吸-负荷潮减弱了南海的半日潮,并加强了南海的全日潮。引潮力的作用也减弱了半日潮而加强了全日潮,但其作用要小于自吸-负荷潮。潮能耗散的分析显示底摩擦耗散在沿岸浅水区域起主导作用,内潮耗散则主要发生在深水区域。内潮耗散的最大值出现在吕宋海峡,且位于南海之外的海峡东部的耗散量大于位于南海之内的海峡西部的耗散量。对M_2和K_1分潮吕宋海峡的内潮耗散总值分别达到16和23GW。  相似文献   

乐清湾内外潮波变形及不对称性分析     

童朝锋  安福伟  章家保  曲开成  孟艳秋 《海洋工程》2020,38(3):113-123

海湾内外的潮波变形及其不对称性影响海湾内外动力输送和水体交换。利用乐清湾内外共9个测站连续潮位进行调和分析,得到该海湾内外各分潮变化规律,利用潮不对称性偏度计算方法确定湾内外潮汐不对称性时空变化特征,比较了主要分潮组合对潮汐不对称性的贡献度,通过数值研究探讨了湾内偏度比湾外偏度值更小的主要成因,分析了湾内外围垦工程对潮不对称偏度的影响。研究发现:乐清湾内潮汐不对称偏度值为负,表现为落潮占优,同期湾外洞头站偏度值为正,与邻近瓯江、飞云江河口的潮不对称偏度变大、表现涨潮占优的变化规律相反;湾外沿岸各站偏度由东北向西南逐渐增大,由落潮占优向涨潮占优变化;潮汐不对称性偏度呈周期性变化,分析确定M2-M4、M2-S2-MS4分潮组合对潮不对称贡献大,该海域潮汐不对称的强度主要由浅水分潮振幅控制,而相对相位则决定潮汐不对称的方向;数值研究探讨表明,湾内大范围的浅滩地形是其潮汐不对称落潮占优的主要原因,围垦将削弱湾内的落潮占优。  相似文献   

Influences of diel and tidal cycles on fish assemblage in eelgrass (Zostera marina) bed of southern Korea during autumn     

KWAK Seok Nam  PARK Joo Myun  IM Seong Oh  JAWAD Laith A. 《海洋学报(英文版)》2018,37(4):40-47

Short-term tidal and diel variations of autumn fish assemblage in a Zostera marina bed were investigated using 3 h interval samplings for 24 h in both spring and neap tide using a small beam trawl. A total of 1 346 fishes belonging to 19 species were collected at spring tide, whereas 1 115 fishes belonging to 17 species were at neap tide. The common fish species were Nuchequula nuchalis, Acanthogobius flavimanus, Takifugu niphobles, Acentrogobius pflaumii, and Pholis nebulosa with the former three species dominating at spring tide, while the latter two species being abundant at neap tide. Diel variation in abundance was significant with higher abundance at night than day, but there were no significant differences between spring and neap tides, and between ebb and flood tides (three-way ANOVAs). Diel variation in the abundance of fishes may be influenced by tidal range and cycle, and day-night differences of food availability and behaviors of fishes indirectly. Non-metric multidimensional scaling (nMDS) ordination and analysis of similarity (ANOSIM) results revealed significant differences in species compositions both between day and night, and between spring and neap tide. Eelgrass beds are highly productive marine ecosystem, and thus, our results will contribute to conservation of seagrass ecosystem in the study area.  相似文献   

基于海上实测的秋刀鱼舷提网沉降和提升性能研究   总被引：1，自引：0，他引：1  

石永闯  朱清澄  花传祥  张衍栋 《海洋通报》2018,(4):459-467

根据2015年7-10月和2016年6-10月蓬莱京鲁渔业有限公司"鲁蓬远渔019"在西北太平洋进行的海上秋刀鱼舷提网网具性能测试所获得的数据,采用线性回归方法,分析了舷提网在沉降和提升阶段,网衣的沉降深度和提升深度以及网具沉降速度和提升速度的变化状况。利用广义加性模型(GAM)探讨秋刀鱼舷提网沉降深度和提升速度各自有效的影响因子,且分析了这些影响因子与舷提网主要性能参数两者之间的关系。结果发现:(1)网衣沉降深度随时间连续增加;网具下纲和侧纲的沉降速度都是先逐渐增大,然后缓慢减小,直至沉降过程结束;网衣沉降速度波动剧烈,无规律性变化。(2)网具下纲、侧纲的提升速度均快速达到最大值然后随时间连续降低,下纲的最大提升速度大于侧纲,网衣提升速度无规律性变化,上下波动剧烈。(3)GAM模型结果显示,30 m水层流速、60 m水层流速、下纲纲索松放长度3个因子对网衣最大沉降深度有显著性影响(P0.05),影响程度依次为30 m水层的流速下纲纲索松放长度60 m水层流速。30 m水层流速和绞网速度两个因子对平均提升速度有着显著性影响(P0.05),其中,绞网速度影响最大。  相似文献