A climatology of mesoscale model simulated low-level wind jets over Cook Inlet and Shelikof Strait, Alaska     

Haibo Liu  Peter Q. Olsson  Karl P. Volz  Han Yi 《Estuarine, Coastal and Shelf Science》2006,70(4):551

Weather in the North Gulf of Alaska is characterized by a high frequency of deep synoptic-scale low-pressure systems, especially during the cold season. The strong pressure gradients of these storms interact with the extremely rugged terrain of the coastal mountains to produce a variety of channeled flows. These surface wind regimes are not well documented in the scientific community, due to the paucity of observations. Modeling of these phenomena in regions of complex terrain is of great interest to those working with hydrodynamic, wave, and pollutant transport models in coastal and shelf areas. Such models, when coupled with ocean and coastal-ecology counterparts, give a broad view of the role surface winds play in shaping local coastal marine ecosystem in this region. This paper presents a climatology of simulated low-level wind jets over the domain of Cook Inlet and Shelikof Strait along Alaska's south-central coast. Daily simulations using the RAMS model were conducted in a 36-h forecast mode for the cold-season period 10/1/03 to 3/31/04. Systematic analysis of the resulting simulated low-level wind field makes it possible to characterize these jets and gap flows in spatial and temporal detail. The comparison between the RAMS winds and the Synthetic Aperture Radar (SAR)-derived winds when available verifies the existence of these wind jets and the capability of the model to simulate these cases. Clearly, the results of a study in this region depend on the fidelity of the model at these scales (O[5 km]). The SAR comparisons attempt to help establish this. From the 6 months of simulations over Cook Inlet and Shelikof Strait, the low-level wind jets are classified into 10 different regimes by location and orientation. These regimes are categorized into four more general groups: cross-channel westerly, easterly, and up and down Inlet flows. The nature of a particular regime is largely a function of pressure gradient orientation and local topography. Jets in the same group have a similar occurrence distribution with time. Some form of jet occurred in the study region almost daily each month of the period, with December 2003 having the highest frequency of wind jets.  相似文献   

超短基线声学定位原理及其应用   总被引：11，自引：1，他引：11  

冯守珍  吴永亭  唐秋华 《海岸工程》2002,21(4):13-18

声学定位系统（Acoustic Positioning System)的技术研究和应用开发在现代海洋科学调查中起着重要作用。以挪威Simrad公司的HPR410P超短基线定位系统为例，从几方面讨论了超短基线（Ultrashort Baseline)声学定位系统的原理、应用范围、定位误差来源及其相应的修正方法；通过最大程度地减少误差来提高系统的定位精度，从而获取高质量的海洋科研调查资料。  相似文献   

动荷载作用下海底粉土的孔压响应及其动强度   总被引：5，自引：0，他引：5  

冯秀丽  叶银灿  马艳霞  林霖 《中国海洋大学学报(自然科学版)》2002,32(3):429-433

本文选用近海分布较广的粉土为研究对象 ,利用室内动三轴试验结果 ,找出动荷载作用下粉土的动应力应变关系 ,分析模拟波浪荷载作用下粉土中的孔压响应、临界循环次数 ,确定波浪作用下粉土的应力状态、破坏临界循环次数 ,判断不同深度处的粉土发生液化的可能性及发生液化所需要的时间 ;研究粉土在动荷载作用下的强度降低 ,为海上工程设计和施工提供科学依据。  相似文献   

利用卫星遥感技术监测赤潮的研究   总被引：8，自引：0，他引：8  

丛丕福  赵冬至  曲丽梅 《海洋技术学报》2001,20(4):69-72

赤潮灾害的频繁发生，给海洋生态环境和海洋渔业经济造成了严重危害。卫星遥感技术的不断完善，为快速、有效地动态监测赤潮灾害提供了可能，通过卫星图片的校正、合成、分析、解释、判断分析，可以迅速连续地掌握赤潮的发生状况，对于研究防控和治理赤潮灾害有着十分重要的意义，本文就如何利用卫星遥感技术监测赤潮进行了探讨。  相似文献   

高分辨率遥感技术在厦门海湾生态环境调查中的应用   总被引：5，自引：0，他引：5  

林桂兰  孙飒梅  曾良杰  庄世坚 《台湾海峡》2003,22(2):242-247,T003

对于局部区域研究，高分辨率卫星遥感及其影像的智能化处理技术是获取信息的新手段．本文以IKONOS遥感影像在厦门海湾的应用为例，探讨高分辨率遥感卫星影像应用于海湾生态环境调查与分析的应用技术．通过分析高分辨率影像地物特征，提出高分辨率遥感影像的重要处理技术：采用不同缩放尺度进行分类和利用空间特征及纹理结构进行专题信息提取。  相似文献   

遥感与GIS支持下的海洋渔业空间分布研究——以东海为例   总被引：9，自引：1，他引：9  

杜云艳  周成虎  崔海燕  苏奋振  刘宝银 《海洋学报》2002,24(5):57-63

基于海洋渔业多年来生产实践所表明的海洋渔场与海洋水文要素密切相关性,将研究区的遥感融合信息与生产数据进行GIS空间配准,同时建立了诸多要素数据的空间聚类模式,利用该模式提取了水文信息和中心渔场信息相关联的空间分布规律的隐伏信息,由此阐述了实现海洋渔业现代化,应用空间遥感融合信息和GIS支持下指导海洋渔业生产的渔情预报有着重要意义.  相似文献   

A semi-analytical solution for random wave-induced soil response and seabed liquefaction in marine sediments     

Haijiang Liu  Dong-Sheng Jeng   《Ocean Engineering》2007,34(8-9):1211-1224

In this study, unlike most previous investigations for wave-induced soil response, a simple semi-analytical model for the random wave-induced soil response is established for an unsaturated seabed of finite thickness. Two different wave spectra, the B-M and JONSWAP spectra, are considered in the new model. The influence of random wave loading on the soil response is investigated by comparing with the corresponding representative regular wave results through a parametric study, which includes the effect of the degree of saturation, soil permeability, wave height, wave period and seabed thickness. The maximum liquefaction depth under the random waves is also examined. The difference on the soil response under the two random wave types, B-M and JONSWAP frequency spectra, is also discussed in the present work.  相似文献   

Atmospherically-promoted photosynthetic activity in a well-mixed ecosystem: Significance of wet deposition events of nitrogen compounds   总被引：1，自引：0，他引：1  

C. Boulart  P. Flament  V. Gentilhomme  K. Deboudt  C. Migon  F. Lizon  M. Schapira  A. Lefebvre 《Estuarine, Coastal and Shelf Science》2006,69(3-4):449

Wet atmospheric deposition of dissolved N, P and Si species is studied in well-mixed coastal ecosystem to evaluate its potential to stimulate photosynthetic activities in nutrient-depleted conditions. Our results show that, during spring, seawater is greatly depleted in major nutrients: Dissolved Inorganic Nitrogen (DIN), Dissolved Inorganic Phosphorus (DIP) and Silicic acid (Si), in parallel with an increase of phytoplanktonic biomass. In spring (March–May) and summer (June–September), wet atmospheric deposition is the predominant source (>60%, relative to riverine contribution) for nitrates and ammonium inputs to this N-limited coastal ecosystem. During winter (October–February), riverine inputs of DIN predominate (>80%) and are annually the most important source of DIP (>90%). This situation allows us to calculate the possibility for a significant contribution to primary production in May 2003, from atmospheric deposition (total input for DIN ≈300 kg km⁻² month⁻¹). Based on usual Redfield ratios and assuming that all of the atmospheric-derived N (AD-N) in rainwater is bioavailable for phytoplankton growth, we can estimate new production due to AD-N of 950 mg C m⁻² month⁻¹, during this period of depletion in the water column. During the same episode (May 2003), photosynthetic activity rate, considered as gross primary production, was estimated to approximately 30 300 mg C m⁻² month⁻¹. Calculation indicates that new photosynthetic activity due to wet atmospheric inputs of nitrogen could be up to 3%.  相似文献   

海底剖面声阻抗分布声遥测模拟实验研究     

杨振华  林俊轩  马恒仁 《中国海洋大学学报(自然科学版)》1989,(4)

本文介绍一种声遥测海底平面层系声阻抗分布的模拟实验结果。实验在油漆厂冷却水池中进行,采用取样平均迭代的反演方法,对三介质层系的遥测结果与实测值较好地接近。  相似文献   

半潜式超大浮体连接器动力特性的一种时间序列分析方法   总被引：1，自引：2，他引：1  

王璞  余澜 《海洋工程》2002,20(3):9-13

根据刚性模块弹性连接器 (RMFC)假设研究由 3个模块连接而成的半潜式超大浮体MobileOffshoreBase(MOB)的波浪载荷动力响应。模块和连接器动力响应根据时间序列法计算 ,这种方法包括海况模拟 ,波浪载荷计算和结构响应计算三个主要部分。通过对结构的适当简化 ,根据Airy波理论 ,Morrison公式以及流体中的结构运动方程、弹性连接器变形方程 ,计算求得MOB在不规则海况下的动力响应 ,并将其与相关文献中的结果进行比较 ,表明该方法有良好的精确性  相似文献