On the effect of mantle conductivity on the super-rotating jets near the liquid core surface     

K.A. Mizerski  K. Bajer 《Physics of the Earth and Planetary Interiors》2007,160(3-4):245-268

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Dynamic Linkage between the North Pacific and the Tropical Pacific: Atmosphere-Ocean Coupling     

LI Chun  WU Lixin 《大气科学进展》2013,30(2):306-314

In this study, dynamic linkage of atmosphere-ocean coupling between the North Pacific and the tropical Pacific was demonstrated using a large number of ensemble perturbed initial condition experiments in a fully coupled fast ocean-atmosphere model (FOAM). In the FOAM model, an idealized mixed layer warming was initiated in the Kuroshio-Oyashio extension region, while the ocean and atmosphere remained fully coupled both locally and elsewhere. The modeling results show that the warm anomalies are associated with anomalous cyclonic winds, which induce initial warming anomalies extending downstream in the following winter. Then, the downstream warming spreads southwestward and induces SST warming in the equatorial Pacific via surface wind-evaporation-SST feedback. Warming in the tropical Pacific is further reinforced by Bjerknes’ feedback.  相似文献   

Impacts of Polar Vortex, NPO, and SST Configurations on Unusually Cool Summers in Northeast China.Part Ⅰ: Analysis and Diagnosis     

LIAN Yi  SHEN Baizhu  LI Shangfeng  ZHAO Bin  GAO Zongting  LIU Gang  LIU Ping  CAO Ling 《大气科学进展》2013,30(1)

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Isolating mesoscale coupled ocean–atmosphere interactions in the Kuroshio Extension region     

《Dynamics of Atmospheres and Oceans》2013

The Kuroshio Extension region is characterized by energetic oceanic mesoscale and frontal variability that alters the air–sea fluxes that can influence large-scale climate variability in the North Pacific. We investigate this mesoscale air-sea coupling using a regional eddy-resolving coupled ocean–atmosphere (OA) model that downscales the observed large-scale climate variability from 2001 to 2007. The model simulates many aspects of the observed seasonal cycle of OA coupling strength for both momentum and turbulent heat fluxes. We introduce a new modeling approach to study the scale-dependence of two well-known mechanisms for the surface wind response to mesoscale sea surface temperatures (SSTs), namely, the ‘vertical mixing mechanism’ (VMM) and the ‘pressure adjustment mechanism’ (PAM). We compare the fully coupled model to the same model with an online, 2-D spatial smoother applied to remove the mesoscale SST field felt by the atmosphere. Both VMM and PAM are found to be active during the strong wintertime peak seen in the coupling strength in both the model and observations. For VMM, large-scale SST gradients surprisingly generate coupling between downwind SST gradient and wind stress divergence that is often stronger than the coupling on the mesoscale, indicating their joint importance in OA interaction in this region. In contrast, VMM coupling between crosswind SST gradient and wind stress curl occurs only on the mesoscale, and not over large-scale SST gradients, indicating the essential role of the ocean mesocale. For PAM, the model results indicate that coupling between the Laplacian of sea level pressure and surface wind convergence occurs for both mesoscale and large-scale processes, but inclusion of the mesoscale roughly doubles the coupling strength. Coupling between latent heat flux and SST is found to be significant throughout the entire seasonal cycle in both fully coupled mode and large-scale coupled mode, with peak coupling during winter months. The atmospheric response to the oceanic mesoscale SST is also studied by comparing the fully coupled run to an uncoupled atmospheric model forced with smoothed SST prescribed from the coupled run. Precipitation anomalies are found to be forced by surface wind convergence patterns that are driven by mesoscale SST gradients, indicating the importance of the ocean forcing the atmosphere at this scale.  相似文献   

赤道太平洋高低频纬向环流差异及其物理机制     

金晨阳  张文君  刘超 《气象学报》2020,78(2):187-198

利用1982—2017年欧洲中期天气预报中心再分析资料和美国国家大气海洋管理局的观测资料,分析了赤道太平洋高、低频海平面气压距平场的特征及差异,并通过诊断赤道太平洋海-气耦合的时间尺度,探讨了导致赤道太平洋高、低频纬向环流差异的原因。结果表明,南方涛动海平面气压东西跷跷板耦合现象只是在低频场中才存在,在高频场中并不存在。低频场上,主要受到热带最明显的年际信号(ENSO)的调控,海平面气压场和海表温度场呈现出东西振荡型。相比而言,在高频场上由于时间短,海、气异常还没有发生较好的耦合,气压场和风场呈现出全海域一致型。高频纬向环流与热带季节内振荡（MJO）紧密联系,具有明显的东传特征,传播速度大约为5 m/s,其变率方差的34%可以由MJO线性解释。相干谱分析表明海-气耦合具有时间依赖性,南方涛动通常只在20候以上的时间尺度才能存在,这与赤道海洋开尔文波横穿太平洋时间相当。   相似文献   

复杂网络牵制控制概述     

曹进德  宋强  刘芳  程尊水 《南京气象学院学报》2020,12(1):22-30

本文回顾了十多年来复杂网络牵制控制的研究进展,对复杂网络现有的牵制控制算法进行了归纳分类,然后基于网络拓扑及节点动力学特性讨论了网络牵制控制的一些必要或充分条件.针对牵制控制下的复杂网络,重点论述了牵制节点的选取策略,综合分析了牵制节点个数、耦合强度、牵制控制增益及节点动力学等因素对复杂网络牵制控制的影响,讨论了具有合作竞争关系符号网络牵制控制的进展,并简要介绍了复杂网络牵制控制的一些应用前景.最后,就复杂网络牵制控制将来的研究方向提了一些建议及展望.  相似文献   

掘进工作面瓦斯流动规律数值模拟分析   总被引：1，自引：0，他引：1  

梁冰  刘蓟南  孙维吉  李宏艳 《中国地质灾害与防治学报》2011,22(4):46-51

研究煤层巷道掘进过程瓦斯流动规律对认识掘进巷道瓦斯涌出规律和瓦斯治理具有重要的理论意义和现实意义。本文通过建立流固耦合模型,考虑煤与瓦斯流固耦合作用,进行了不同掘进长度,掘进工作面瓦斯压力分布规律,瓦斯压力梯度改变以及瓦斯流动规律的数值模拟研究。研究表明,掘进巷道周边煤层瓦斯压力随煤壁暴露时间的增长逐渐降低,采掘活动对工作面前方煤体的影响范围达30m。并且越靠近煤壁瓦斯压力梯度越大,在距离巷帮5m范围内,瓦斯压力变化幅度最大。煤壁瓦斯流速随巷道掘进长度的增加先增加后减小,最后瓦斯流速趋于稳定。掘进工作面瓦斯流动规律的研究为矿井瓦斯治理提供安全可靠的依据,保证矿井安全生产。  相似文献   

青藏高原天然气水合物形成的空间耦合关系探讨   总被引：2，自引：0，他引：2  

周强  李万伦  陈伟涛  王永江 《冰川冻土》2011,33(5):1139-1145

通过对青藏高原地质、地理资料的收集和综合归纳,分析了青藏高原油气地质演化、高原隆升、冻土生成、冰川推移与天然气水合物成生的关系,探讨了青藏高原油气地质与天然气水合物在时空上的耦合关系.初步认为,青藏高原分布的大面积的海相中生界烃源岩为冻土天然气水合物的形成提供了丰富的物源基础;尤其是碳酸盐岩和泥（页）岩,为主力烃源岩,...  相似文献   

Analysis of wave-induced liquefaction in seabed deposits of silt   总被引：1，自引：0，他引：1  

高玉峰  沈扬  张健  黎冰 《中国海洋工程》2011,25(1):31-44

The dynamic stress introduced in half elastic space by wave loading is characterized by the equation between the magnitude of half cyclic axial stress and cyclic torsion shear stress and the principal stress,whose direction rotates continuously and compression stress on seabed can be calculated by the use of small amplitude wave theory.With relationship curves of saturated silt of liquefaction cycles and cyclic stress ratios obtained by cyclic triaxial-torsional coupling shear tests and curve fitting method to different data points of relative density,it is suggested that the cyclic stress ratio corresponding to constant liquefaction impedance be taken as the critical cyclic stress ratio which implies liquefaction.There exists a linear relationship between critical cyclic stress ratio and relative density under different relative densities.Empirical formula for critical cyclic stress ratios of seabed liquefaction induced by wave loading under different relative densities is established.The possibility of seabed silt liquefaction and its influence factors are analyzed based on the small-amplitude wave theory and the data acquired in laboratory tests.  相似文献   

国外城市交通系统的空间研究进展     

刘承良  余瑞林  曾菊新 《世界地理研究》2011,20(1):79-87

城市交通空间研究历史悠久,最早追朔到19世纪初,整体上经过了萌芽探索（19世纪初至19世纪末）、深化发展（20世纪初至50年代）、快速发展（20世纪60年代至80年代）和丰富全面（20世纪90年代以来）四个阶段：研究领域主要集中于交通—城市空间耦合、城市交通空间通达性、空间句法及形态、空间复杂性等方面,其中交通—城市空间耦合研究历史久远,贯穿始末,空间通达性兴起于20世纪60年代,空间句法集中于20世纪70-80年代,空间复杂性则起步较晚,兴盛于21世纪初;整体上,国外城市交通空间复杂性研究薄弱,集成复杂系统科学理论／方法,结合GIS地计算的城市交通空间复杂性规律研究势必成为未来研究的重心和中心。  相似文献