台湾海峡及厦门湾台风浪场数值模拟

本文利用国际上先进的第三代海浪模式SWAn,在充分考虑风能量输入、白浪效应、水深诱导的波浪破碎、底摩擦、波-波间的非线性相互作用等物理过程。以0604号台风“碧利斯“为例,通过嵌套计算方式,模拟了台湾海峡及厦门湾台风浪场的分布特征。将数值模拟结果与浮标测站实测资料对比分析,结果表明台风浪高模拟值与实际台风资料相符较好,可以为该海域台风浪的模拟提供较好的参考

Study on water exchange characters in the Shenhu Bay

纳潮量与水交换时间的大小直接决定了半封闭海湾内污染物的稀释速率,因此对其进行深入探讨对于预测湾内水质的长期变化具有重要意义。本文以11个分潮共同驱动一个三维斜压海流模式用以模拟深沪湾的潮汐潮流,进而计算出深沪湾的纳潮量。另外,浓度为1 g/m3的保守示踪物在模型启动之初被作为初始条件均匀投放在湾内,观察其后示踪物浓度随涨落潮流的变化情况,进而可以估算出深沪湾的半交换周期约为14 d。Both of the tidal prism and period of water exchange are generally used as an index to examine the dilution rate of pollutants in a semi-enclosed bay,so understanding them is significant to predict the long-term variation of water quality.Eleven tides are used to force the baroclinic coastal model by a three dimensional to reproduce the tidal regime in the Shenhu Bay.Based on the validated simulations,the tidal prism is estimated further,which also is unanimous with our observations.In addition,the period of water exchange is numerically examined by means of the concentration(mass) variation of conservative tracers,which were set to be 1 gm-3 initially.It is suggested that the half-exchange time is about 14 d.中国博士后科学基金资助(20060400737

营养盐负荷对浮游植物水华影响的模型研究

运用一个耦合的生物物理模型模拟了渤海初级生产力,浮游植物生物量和氮磷含量的季节变化特征,模拟结果与实测值吻合较好.在模型验证的基础上,进一步考察了两种营养盐负荷--河流和沉积物对渤海生态系统动力过程的影响,发现河载营养盐对渤海生态体系的影响主要集中在河口水域,而限制沉积物中的营养盐进入水体则能显著抑制渤海范围内藻类水华的爆发

Model for study on impact of external nutrient sources on the algalbloom

运用一个耦合的生物物理模型模拟了渤海初级生产力,浮游植物生物量和氮磷含量的季节变化特征,模拟结果与实测值吻合较好。在模型验证的基础上,进一步考察了两种营养盐负荷——河流和沉积物对渤海生态系统动力过程的影响,发现河载营养盐对渤海生态体系的影响主要集中在河口水域,而限制沉积物中的营养盐进入水体则能显著抑制渤海范围内藻类水华的爆发。A coupled bio-physical model is used to simulate the seasonal variation of primary production,chlorophyll a,nitrogen and phosphorus in the Bohai sea,and the modeled results agree with the observations reasonably.Based on the validated simulations,the impact of two external nutrient sources on the Bohai ecosystem is further examined.It is found that the influence of river-borne nutrients mainly concentrate on estuaries,whereas the reduction of sediment-borne nutrients may seriously inhibit the onset of algaelbloom in the whole Bohai sea.中国科学院海洋环流与波动重点实验室开放课题(KLOCAW0804);; 中国博士后科学基金资助项目(20060400737)~

Numerical simulation of the seasonal variations of the stratification and tidal front in the Bohai Sea

采用三维斜压海流模式(POM)模拟了渤海海温的季节变化,以海表与海底温差ΔT作为判别依据,发现3月份前整个渤海的表、底温差小于0.5℃,说明渤海处于充分混合状态;进入4月份以后,莱州湾、渤海中部以及渤海海峡的局部水域出现超过2℃的表、底温差,意味着垂向层化结构开始形成;层化区域面积随着海表热通量增大的趋势可一直持续到8月,9月后由于日照量逐渐减小,季节性温越层逐渐消失,11月以后渤海又恢复到充分混合的状态。A 3-D baroclinic ocean model is used to simulate the seasonal variation of temperature in Bohai Sea.Based on the difference(ΔT) of sea surface temperature(SST) and sea bottom temperature(SBT),it is found that ΔT is less than 0.5 ℃ throughout Bohai Sea before March,meaning that water column is mixed sufficiently;when April comes,the over 2℃ temperature difference occurs in Laizhou Bay,central basin and Bohai Sea strait,implying that the vertical stratification comes into being;the tendency that stratification area increases with heat flux through sea surface can extend to August.Thereafter,with the decreased irradiation and strengthened tidal mixing as well as wind stirring,the seasonal thermocline disappears gradually,and the water column resumes the fully mixed state.中国博士后科学基金资助项目(20060400737)~

Intratidal variation of the water column in Quanzhou Bay

泉州湾6个站点的观测数据显示:内湾涨潮流历时由底层向表层逐渐变短,而落潮流历时则逐渐变长;同时,各个站点实测的盐度水深结构也具有明显的潮周期变化特征,这可能与局地水体的层化和混合机制的交替变化密切相关.进一步定量分析S2站位上影响水体结构变化的四种机制发现:外湾的河口环流作用与潮汐张力、风混合以及潮汐混合作用相比要小一个量级.在一般天气条件下的大潮周期,潮汐混合与潮汐张力相互竞争是导致水体结构交替变化的根本原因;小潮周期由于潮流混合作用减弱,水体层化现象得以持续较长时间,风的搅动在特定时刻可以起到削弱层化结构的作用.Observations at 6 ship moorings show that the flooding duration becomes shorter with water depth from sea floor to surface,and the ebbing duration shows an opposite case.Meanwhile,the salinity structure at each station shows an intratidal variation,which is correlated with the alternate competition between stratification and mixing mechanisms.By quantifying 4 mechanisms controlling the vertical configuration of the water column at site 2,it is found that the estuarine circulation is always one order smaller than tidal straining and tidal stirring mechanisms,because the river discharge is small and exerts a weak influence on the outer bay.Under the normal weather condition,it is the competition between tidal straining and tidal mixing that brings about the alternate appearance of stratification and destratification in the water column during the spring cycle;whereas during the neap,stratification is able to last for a long time due to the weak tidal mixing,though strong wind stirring may break the stratification at given time.中国科学院海洋环流与波动重点实验室开放研究基金资助项目(KLOCAW0804);中国科学院院长优秀奖获得者科研启动资金资助项目(AJ0809CX-033

The Sediment Properties and Transportation Rules of the Xiuyu Sea-route in Meizhou Bay

湄洲湾秀屿港是福建海岸重要的港口之一,港口发展需要了解湄洲湾海域的海流及悬沙分布变化特征.本研究对湄洲湾秀屿港进港航道3个站位进行周日连续水文、泥沙观测,通过对获取的数据进行分析比较,得出湄洲湾秀屿进港航道泥沙变化特征和运移特征.湄洲湾潮流为正规半日潮流.由于受地形所制约,潮流为比较稳定的往复流.涨、落急时刻流速大,含沙量随之增大并形成于底层.由于湄洲湾无大径流输沙,周边海岸的侵蚀输沙影响也不大,海域悬沙量浓度主要取决于潮流掀沙.本调查区域悬沙的颗粒主要集中在0.004~0.063 mm,现场测定的海流流速与泥沙的启动流速相关,流速与泥沙的浓度基本是正相关关系.湄洲湾余流总趋势是表层向外,底层向内,在近湾顶的秀屿西北海区存在潮汐余流环流,断面净输沙量进大于出.The Xiuyu port in Meihou bay is one of the most important ports in Fujian.The development of this port needs the date of sediment and current properties.This paper did an investigation in three stations for 25 hours,including current and sediment observation.Analyzing this date,we can find the sediment properties and transportation rules.The current in this area is regular semi-diurnal tide;the tidal current motion type is reciprocal because of the topographical restrictive.During flood and ebb fast tide,sediment is increased with the increase of current,and the maximum of it is at bottom.The driver of sediment in this place is tidal current.Because there is not big river discharge in Meizhou bay,and the sediment discharge of seawater eroding coastal is not important in this area.The granularity of the sediment here is from 0.004 mm to 0.063 mm.There is a correlation between the tidal current and the speed of sediment startup.It is a positive correlation between the current and sediment.The direction of stable current is outward at surface and inward at bottom.There is a circumfluence of stable current in the northwest of Xiuyu port.The output of net sediment transportation is bigger than the input

The Analysis of Character of Hydrodynamics and Sediment of Minjiang Estuary

利用闽江口所设置5个定点连续观测站的流速、盐度、温度、浊度与悬沙资料以及同步观测的5个潮位观测站的潮位资料,分析闽江河口的水文特征和悬浮泥沙含量特征.研究表明,闽江口的水文特征有:涨潮历时短,退潮历时长,各潮位观测站的涨潮时刻由河口向感潮河段的上游依次推迟,落潮时刻由感潮河段的上游向河口依次推迟.温、盐分布情况受径流和潮流共同作用,径流对表层水体温度、盐度影响剧烈.在观测时间,观测区域内,温度变化范围在24.9-30.1℃,盐度变化范围在4.1-33.7.输沙量计算结果显示,在测量期间,壶江水道和熨斗水道落潮输沙量大于涨潮输沙量,河口输沙以河流输沙为主.The salinity,temperature and tidal currents at 5 sampling stations in the estuary of Minjiang River were colleted during spring and neap,respectively,and one month of tidal level was also observed and analyzed to the understand the local hydrologic characteristics.It was found that the flood duration is shorter than that of ebb at five stations,and the difference degree increased toward the estuary.It was also found that the distribution of temperature and salinity was affected by both river runoff and tidal currents: the influence of river discharge on salinity and temperature mainly concentrates on surface layer of the water column due to the freshwater buoyancy,whereas the tide influence was limited to the bottom layer due to vertical stratifications.The variation range of temperature was between 24.9℃ and 30.1℃ and the range of salinity was between 4.1 and 33.7,with higher temperature and lower salinity toward the mouth of Minjiang.The observations show that the sediment content on the ebb is higher than that on the flood in both HuJiang and YunDou channels,meaning that the river discharge plays a significant role in sediment transportation

Analysis and risk assessment of the oil spill in Xiamen Bay

本文使用数理统计与概率的相关知识,并且根据厦门湾近几年进出船舶的统计资料,估算了未来几年中厦门湾海域船舶突发性溢油事故发生的概率.结果表明,厦门湾未来几年的溢油发生概率为0.27次/A.然后运用数值模拟方法对假设的突发溢油事故中溢油的扩展进行预测分析并结合建立的欧拉潮流场对油膜的漂移路径进行研究,分别从高潮、低潮、涨急、落急四个时刻开始计算溢油路径,结果显示油膜影响范围可从海沧南部延伸至浯村屿东部,根据模拟结果可对突发溢油的风险进行评估.Based on recent data of ship activities from Xiamen maritime affairs,we estimate the probability of oil spill occurring in Xiamen Bay in coming years using probability theory and statistics methods.The results show that the oil spill probability is 0.27 times/a.Thus,the numerical simulation is employed to forecast and analyze the expansion of the hypothetical oil spill incidents and the path of the oil spills by the help of Euler trend field.The paths is simulated in 4 phases at high tide,low tide,flood tide and ebb tide.It shows that the sphere of influence is from the south of Haicang to the east of the Wucun Island.So,the risk can be assessed by simulation when there is oil spill

The Numerical Simulation of Wind Waves in Xiamen Bay

通过采用目前国际上较为先进的第三代近岸海浪数值模型SWAn(SIMulATIOn WAVES nEArSHOrE),实现厦门湾常风浪场的数值模拟.先分别计算平潭、崇武、东山3个海洋观测站16个风向的多年平均风场,实现台湾海峡常风浪场的数值模拟,再将模拟结果嵌套入厦门湾,根据实测风场,进行厦门湾常风浪场的数值模拟.模拟结果显示厦门湾常风浪场主要受两个因素的影响,一是风的作用,二是从台湾海峡传进港湾的波浪.厦门湾湾口的有效波高和有效周期均大于湾顶.在主风向风作用下,湾口区有效波高可达1.8 M,有效周期可达6 S,湾顶则约为0.2 M和2.1 S.The study is about the waves′ simulation of Xiamen Bay.First,based on the average wind field according to 3 marine observation Stations′ data from 1960 to 1980,the waves of the Taiwan Strait were simulated by the SWAN model.Then,using the first step′s result and the observational wind data of Xiamen Bay,the waves′ simulation of the Xiamen Bay were realized by the self-nested method.The simulation results showed that there were two primary factors influence the wave field of Xiamen Bay.One is the wind field,the other is the wave from the Taiwan Strait.The significant wave height and period of mouth area are larger than the head area in Xiamen Bay.Under the condition of Prevailing winds,the significant wave height can reach 1.8 m in the mouth area and 0.2 m in the head area,the significant wave period is about 6 s in the mouth area and 2.1 s in the head area.福建省自然科学基金(W0650015)资