Simulation of double cold cores of the 35°N section in the YellowSea with a wave-tide-circulation coupled model

Based on the MASNUM wave-tide-circulation coupled numerical model, the temperature structure along 35°N in the Yellow Sea was simulated and compared with the observations. One of the notable features of the temperature structure along 35°N section is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located near 122°E and 125°E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores are discussed. At least two reasons make the temperature in the center (near 123°E) of the section higher than that near the west and east shores in winter. One reason is that the water there is deeper than the west and east sides so its heat content is higher. The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter. This temperature pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 30m) is heated and s     

海洋赤潮生态模型参数优化研究

根据中日合作海洋生态围隔试验观测资料,对乔方利等１９９８年提出的赤潮过程生态模型（乔方利等,２０００）进行参数优化研究,得到赤潮过程营养２盐半饱和常数：硅藻,ＫＮ＝１．４ｕｍｏｌ／Ｌ、ＫＰ＝０．１２９ｕｍｏｌ／Ｌ、ＫＳｉ＝１．１６ｕｍｏｌ／Ｌ;鞭毛藻,ＫＮ＝０．３４５ｕｍｏｌ／Ｌ、ＫＰ＝０．１１３ｕｍｏｌ／Ｌ以及其它等共１８个参数的最优取值,并详细讨论了目标泛函的构造和多目标函数参数优化的方法。     

基于二阶矩闭合模式平衡解的海浪生湍流混合系数解析估计

从次小尺度海洋运动方程和运动近各向同性假定出发,本文给出高确定性的海洋湍流二阶矩闭合方程和特征量变化方程.这组方程描述波动、涡旋和环流等较大尺度运动对海洋湍流的剪切不稳定性生成机制.同时,基于海浪破碎是湍流海面生成主要机制的认识,本文按破碎海浪统计理论给出湍流特征量变化方程的海面边界条件,包括由破碎能量损耗和卷入深度分别确定的海面动能通量和动能耗散率.根据上层海洋湍流特征量方程的平衡解和关于动能耗散率的观测资料,本文得到海浪生湍流混合系数的解析估计.所得到的海浪生湍流动能耗散率与观测资料进行了定性与定量对比,混合系数与先前Prandtl混合长度理论估计的一致性检验.     

2007和2012年北极最小海冰范围空间分布不同的原因分析

Satellite records show the minimum Arctic sea ice extents(SIEs) were observed in the Septembers of 2007 and2012, but the spatial distributions of sea ice concentration reduction in these two years were quite different.Atmospheric circulation pattern and the upper-ocean state in summer were investigated to explain the difference.By employing the ice-temperature and ice-specific humidity(SH) positive feedbacks in the Arctic Ocean, this paper shows that in 2007 and 2012 the higher surface air temperature(SAT) and sea level pressure(SLP)accompanied by more surface SH and higher sea surface temperature(SST), as a consequence, the strengthened poleward wind was favorable for melting summer Arctic sea ice in different regions in these two years. SAT was the dominant factor influencing the distribution of Arctic sea ice melting. The correlation coefficient is –0.84 between SAT anomalies in summer and the Arctic SIE anomalies in autumn. The increase SAT in different regions in the summers of 2007 and 2012 corresponded to a quicker melting of sea ice in the Arctic. The SLP and related wind were promoting factors connected with SAT. Strengthening poleward winds brought warm moist air to the Arctic and accelerated the melting of sea ice in different regions in the summers of 2007 and 2012. Associated with the rising air temperature, the higher surface SH and SST also played a positive role in reducing summer Arctic sea ice in different regions in these two years, which form two positive feedbacks mechanism.     

南海北部陆架海域内潮特征的观测研究

利用2014年南海东沙岛西北部海域70余天的流速剖面高频观测资料,研究分析了该海区正压潮、内潮的时空分布特征。结果表明,观测海区正压潮流以O_1,K_1,M_2,S_2为主;斜压潮流中,除四大分潮之外,MU_2与2Q_1分潮能量也较强;内潮的主轴方向基本沿东南-西北方向,近似与局地等深线垂直。全日内潮的锁相部分占全日内潮能量的17.5%,而半日内潮的锁相部分占半日内潮能量的30%;进一步研究发现半日内潮主要由第一模态主导,而全日内潮第二模态占比50%,约为其第一模态能量的两倍;内潮模态能量占比显示出显著的大小潮调制的半月周期。对比不同垂向模态计算方法发现,当流速观测深度有限时,利用全水深温盐资料计算观测范围内流速垂向模态是更为准确的方式。     

利用漂流浮标资料对黑潮及其邻近海域表层流场及其季节分布特征的分析研究

利用1987年以来WOCE项目及我国自行投放或进入黑潮及其邻近海域(15°~36°N,114°~135°E)的共计323个卫星跟踪海表面漂流浮标资料,得到全年平均及季节平均的浮标轨迹及(1/4)°×(1/4)°格点平均的表层流矢量结果。分析认为:对于全年平均的表层流场,黑潮表层流路主要表现了对大洋西边界地形的适应,并呈现出6个较大的弯曲,其中在反气旋型弯曲处都发生分支或入侵现象、气旋型弯曲处这种现象却不明显。对于季节平均的表层流场,黑潮表层不同流段分别表现出各自显著的季节差异:吕宋海峡附近海域,表层水向南海的入侵只发生在秋、冬两季,而春、夏两季却不发生;在台湾以东海域,黑潮表层流路与黑潮右侧反气旋涡的存在与否密切相关,春季没有涡旋存在时,黑潮表层流路常出现气旋式大弯曲,其他三个季节反气旋涡存在时,黑潮表层流路相对平直;在台湾东北海域,黑潮表层水向东海南部陆架区的入侵以秋、冬季最强,春季次之,而夏季几乎不发生;在赤尾屿以北的东海黑潮中段,黑潮流动比较稳定,其表层平均流径走向由偏北到偏东依次约为冬(北偏东30°)、春(北偏东33°)、秋(北偏东38°)、夏(北偏东45°);流路宽度由宽至窄依次约为秋(90 km)、春(80 km)、冬(70 km)、夏(60 km),而流速由大至小依次为夏、春、秋、冬,且各季节都表现出北段流速大于南段的现象;在九州西南海域,春、秋两季黑潮表层水发生明显的向北入侵,入侵的黑潮水与东海外陆架水共同成为对马暖流的一部分来源,而夏季这种现象不明显,九州西南海域黑潮表层流路北界的位置以秋季最为偏北(但最北不超过31°N)、流路也最宽;在琉球群岛外缘海域,南半部基本没有北上的表层流存在,只有在冲绳群岛-奄美群岛以东海区,秋、夏、春三季表层反气旋涡旋都比较活跃,在涡旋的西侧有顺着冲绳群岛-奄美群岛的东北向流,其中秋季最为明显。这些结果可以为黑潮及其邻近海域的深入研究提供较为客观、直接的参考。     

东海“桑吉”轮事故溢油污染的长期预测

“桑吉”轮事故溢出的凝析油和燃料油对漂油途经海域的海洋生态会产生长期灾害性影响。对溢油污染水体的漂移轨迹和污染程度及范围的预测可为海洋环境保护及污染评估提供重要基础信息。基于国家海洋局第一海洋研究所研发的海洋环境业务化预报系统,本研究较精确预测了“桑吉”轮事故发生后至沉船位置的漂移轨迹;继而利用拉格朗日粒子追踪法预测了撞船后60天内的油粒子漂流轨迹。结果表明,沉船点附近的溢油主要向东北方向输运,大部分油粒子进入西边界强流黑潮并在黑潮带动下迅速进入黑潮延伸体海域。基于预报系统2009-2017年历史表层海流资料,对溢油影响程度和范围进行了风险概率分析,结果显示受溢油影响最大的区域为沉船点东北方向海域。     

The Flexible Global Ocean-Atmosphere-Land system model, Spectral Version 2: FGOALS-s2

The Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 (FGOALS-s2) was used to simulate realistic climates and to study anthropogenic influences on climate change. Specifically, the FGOALS-s2 was integrated with Coupled Model Intercomparison Project Phase 5 (CMIP5) to conduct coordinated experiments that will provide valuable scientific information to climate research communities. The performances of FGOALS-s2 were assessed in simulating major climate phenomena, and documented both the strengths and weaknesses of the model. The results indicate that FGOALS-s2 successfully overcomes climate drift, and realistically models global and regional climate characteristics, including SST, precipitation, and atmospheric circulation. In particular, the model accurately captures annual and semi-annual SST cycles in the equatorial Pacific Ocean, and the main characteristic features of the Asian summer monsoon, which include a low-level southwestern jet and five monsoon rainfall centers. The simulated climate variability was further examined in terms of teleconnections, leading modes of global SST (namely, ENSO), Pacific Decadal Oscillations (PDO), and changes in 19th–20th century climate. The analysis demonstrates that FGOALS-s2 realistically simulates extra-tropical teleconnection patterns of large-scale climate, and irregular ENSO periods. The model gives fairly reasonable reconstructions of spatial patterns of PDO and global monsoon changes in the 20th century. However, because the indirect effects of aerosols are not included in the model, the simulated global temperature change during the period 1850–2005 is greater than the observed warming, by 0.6°C. Some other shortcomings of the model are also noted.     

球坐标系下MASNUM海浪数值模式的建立及其应用

为开展海浪对海洋上混合层的搅拌混合作用及其对海气界面通量的影响等研究,在LAGFD WAM区域海浪数值模式基础上建立了球坐标系下的全球海浪数值模式.重点导出了球坐标系下的海浪能量谱平衡方程及其复杂特征线方程,该组方程包含了背景流场对波动传播的调整、波动沿大圆传播的折射等.数值积分则采用复杂特征线嵌入计算格式.初步数值模拟结果表明,该海浪全球数值模式能够较为精确地刻画海浪的动力过程.