共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
夏威夷历史海啸记录包含远距离和当地产生的海啸,由这些事件引起的人员伤亡和对建筑、环境造成的破坏与损失是惊人的,但是在近来才有一些对历史海啸沉积事件的综合性的研究.夏威夷多岩石的海岸线的演变主要是海啸和风暴的贡献,然而区分风暴和海啸是很难的,特别是相关的小的历史海啸事件.因此夏威夷海啸的研究往往关注于大的古海啸沉积事件.研究表明远距离产生的事件,如1946年阿留申海啸对瓦胡岛岩石岸线的演变具有重要影响.活火山也有助于岩石岸线的形成,且容易引发当地海啸.现代活动的Kilauea火山南侧海域的逐步沉降并没有引起太平洋范围内的破坏性的大海啸,但引发了局部一系列重要的海啸事件,这些事件的周期被估计认为是200年. 相似文献
5.
本文采用一个简单的模式研究山岳附近锋的传播和变形,这里将锋定义为两种均匀流体的分界面。由这个模式算出来的山岳附近锋的移动的基本特征已予证明。关于网格的分辩率,山地的表述以及高空流的方向和速度等方面,对山地附近锋的传播预报的敏感性作了试验。 一、引 言 冷锋的结构和它的传播速度均受到山脉的强烈影响,冷空气可以受到一个山岳的阻挡,其传播速度就会随之降低。然而,在有利的条件下,当冷锋沿着山脉移动时,它的速度明显加大。这种气流的数值模拟的出现是可能的。(例如,Gauntlett等MWR 112 1984)无论如何,然而预报这种锋的畸变仍然是困难的。 相似文献
6.
宋文洋 《山东海洋学院学报》1985,(C00):273-274
仪器的误差是仪器质量的最重要的技术指标之一。测量仪器的误差概念和准确度的概念是相互关联的。一般情况下,我们把测量仪器的误差理解为仪器的示值(测量值)和被测量的真值之间的差值,而准确度则说明仪器示值与被测量的真值相符合的程度。当我们谈到仪器准确度时就会联想到仪器的误差。从误差的观点来看, 相似文献
7.
地球生态系统的营养盐硅补充机制 总被引:7,自引:0,他引:7
通过海洋生态系统的结构和功能以及海洋生态系统对大气生态系统和陆地生态系统的影响,根据营养盐硅对浮游植物生长的影响过程和浮游植物的生理特征以及其集群结构的改变特点的研究结果,综合分析了硅的生物地球化学过程,探讨了人类对生态环境的影响和生态环境变化对地球生态系统的影响。提出了地球生态系统的营养盐硅的补充机制:近岸的洪水、大气的沙尘暴和海底的沉积物向缺硅的水体输入大量的硅,即由陆地、大气、海底3种途径将硅输入海水水体中,满足浮游植物的生长的需要,保持海洋中浮游植物生长的动态平衡,促进海洋生态系统的可持续发展。 相似文献
8.
海洋中赤潮藻类与浮游动物的相互作用 总被引:3,自引:2,他引:3
浮游动物作为浮游植物的摄食者和调控者 ,它们之间形成复杂的、多样性的相互作用关系。这种相互作用的形式不仅影响着海洋中生物群落的动态变化和演替 ,而且在很大程度上影响着海洋环境的变化。由于藻类与浮游动物之间相互关系的多样性和可变性 ,在不同的种类之间不同的条件下往往表现出不同的相互作用形式 ,使两者之间的关系难以琢磨。随着近海赤潮事件的频繁发生 ,认识赤潮生物对海洋生物群落的影响的需求愈来愈强烈。本文试图以相互作用的多样性为出发点 ,对赤潮藻类与浮游动物之间的关系做出较为清晰的阐述。1赤潮藻类对浮游动物的作用… 相似文献
9.
10.
11.
为了研究南极冰藻的热胁迫应答机制,本文根据转录组测序得到的冰藻Chlamydomonas sp. ICE-L过氧化氢酶CiCAT基因分析了其编码蛋白的特征,同时研究了CiCAT基因表达和过氧化氢酶活性在培养温度升高时的响应变化情况。结果表明:CiCAT基因序列全长为2 066 bp,编码492个氨基酸。在过氧化氢酶的系统进化树中,南极冰藻与其他绿藻聚类为一个分支。CiCAT编码的蛋白序列与盐藻和红球藻的过氧化氢酶序列相似性较高,分别为80.5%和78.9%。当南极冰藻处于热胁迫条件下,CiCAT基因的相对表达量和过氧化氢酶活均呈现出先上升后下降的趋势,但在胁迫24 h时CiCAT基因的表达量变化不明显,而实验组的酶活显著高于对照组。在胁迫72 h时,基因表达量和酶活均达到最高值。研究初步表明,与在常温藻类和高等植物中的功能相似,在经受热胁迫的情况下,南极冰藻中的抗氧化酶系统也发挥着重要作用。 相似文献
12.
极区海冰是全球气候系统的重要组成部分,南极的固定冰普遍存在于其沿海地区,中山站周边固定冰一般在11月中下旬达到最厚。海冰厚度是海冰的重要参数之一,2016年在南极中山站附近3个站点(S1、S2、S3站点)共布放了4套温度链浮标,包括1套SIMBA (Snow and Ice Mass Balance Array)温度链浮标和3套太原理工大学温度链浮标(TY温度链浮标),SIMBA温度链浮标每天观测4次,TY温度链浮标每小时观测1次。利用浮标观测的温度剖面以及海冰和海水间不同介质温度差异计算得到海冰厚度。在S3站点,同时布放了SIMBA温度链浮标和TY温度链浮标。温度链浮标计算冰厚和人工钻孔观测冰厚比较结果显示,S1站点TY温度链浮标计算的海冰厚度平均误差和均方根误差分别为3.3 cm和14.7 cm,S2站点和S3站点分别为6.6 cm、6.9 cm以及4.0 cm、4.8 cm。S3站点的SIMBA温度链浮标计算冰厚和人工观测冰厚的平均误差和均方根误差为8.2 cm和9.7 cm。因而S3站点TY温度链浮标计算的海冰厚度更接近人工观测的结果。进一步对Stefan定律海冰生长模型进行对比,模型计算得到的海冰生长率为0.1~0.8 cm/d,生长率快于TY温度链浮标的结果,且受积雪影响明显。相比于卫星遥感反演冰厚的误差和观测时段的限制以及有限的人工观测,2种温度链浮标未来对于中山站附近海冰的长期监测均有重要的应用价值。 相似文献
13.
Qi Shu Fangli Qiao Jiping Liu Zhenya Song Zhiqiang Chen Jiechen Zhao Xunqiang Yin Yajuan Song 《海洋学报(英文版)》2021,40(10):65-75
To improve the Arctic sea ice forecast skill of the First Institute of Oceanography-Earth System Model (FIO-ESM) climate forecast system, satellite-derived sea ice concentration and sea ice thickness from the Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) are assimilated into this system, using the method of localized error subspace transform ensemble Kalman ?lter (LESTKF). Five-year (2014–2018) Arctic sea ice assimilation experiments and a 2-month near-real-time forecast in August 2018 were conducted to study the roles of ice data assimilation. Assimilation experiment results show that ice concentration assimilation can help to get better modeled ice concentration and ice extent. All the biases of ice concentration, ice cover, ice volume, and ice thickness can be reduced dramatically through ice concentration and thickness assimilation. The near-real-time forecast results indicate that ice data assimilation can improve the forecast skill significantly in the FIO-ESM climate forecast system. The forecasted Arctic integrated ice edge error is reduced by around 1/3 by sea ice data assimilation. Compared with the six near-real-time Arctic sea ice forecast results from the subseasonal-to-seasonal (S2S) Prediction Project, FIO-ESM climate forecast system with LESTKF ice data assimilation has relatively high Arctic sea ice forecast skill in 2018 summer sea ice forecast. Since sea ice thickness in the PIOMAS is updated in time, it is a good choice for data assimilation to improve sea ice prediction skills in the near-real-time Arctic sea ice seasonal prediction. 相似文献
14.
15.
The calculative method of heat transfer coefficient between ice cover and water is analyzed considering the heat balance at ice cover bottom firstly. The heat transfer coefficient is calculated with the meteorological, oceanographic data and sea ice conditions measured on the JZ20-2 Oil/Gas Platform in the Bohai Sea during the winter of 1997/1998. From the results, it is shown that the heat transfer coefficient is smaller in the freezing and melting periods, which is about 0.16× 10-3 and 0.04× 10-3 respectively. In the middle of ice season, the heat transfer coefficient has a larger value, which is about 0.5 × 10-3. Lastly, the influences of ice thickness and ice type on the heat transfer coefficient are discussed. With the heat transfer coefficient determined above, the oceanic heat flux in the winter of 1997~1998 is calculated, and its trend in the winter is analyzed. This study can be referenced in the sea ice numerical simulation and prediction in the Bohai Sea. 相似文献
16.
《Ocean & Coastal Management》2008,51(10):659-670
Marine protected areas and marine reserves are being established in United States ocean waters under several federal and state laws. Relevant laws include the National Marine Sanctuaries Act, the Magnuson–Stevens Fisheries Conservation and Management, the National Monument Act, the federal Submerged Lands Act, and the California Marine Life Protection Act. This article evaluates U.S. place-based ocean management from the perspectives of relevant international law principles and programs and foreign nation experiences relevant to the U.S. It then focuses on the challenges presented in managing multiple uses of U.S. ocean waters in the face of federal and state jurisdictional complexity. Integrating place-based management with fisheries management is given special attention. 相似文献
17.
雪热传导系数是海冰质量平衡过程中的重要物理参数,决定了穿透海冰的热传导通量。北冰洋海冰质量平衡浮标观测获得多年冰上冬季温度链剖面可以明显地区分冰雪界面。本文考虑到冰雪界面处温度随时间变化,再根据冰雪界面热传导通量连续假定,提出了新的雪热传导系数计算方法。受不同环境因素影响,多年冰上各个浮标的雪热传导系数在0.23~0.41 W/(m·K)之间,均值为(0.32±0.08) W/(m·K)。北冰洋多年冰上冬季穿过海冰的热传导通量最大发生在11月至翌年3月,约14~16 W/m2。结冰季节,来自海冰自身降温的热量对穿过海冰向大气传输的热量贡献逐月减少,从9月100%减小到12月的35%,翌年的1月至3月稳定在10%左右。夏季,短波辐射通能量通过热传导自上而下加热海冰,海冰上层温度高于下层,热量传播方向与冬季反向,往海冰内部传递。直到9月短波辐射完全消失,气温下降,热量再次转变为自下往上传递。从冰底热传导来看,夏季出现海冰向冰水界面传递热量现象。由于雪较好的绝热性,冰上覆雪极大地削弱了海冰上层热传导通量,从而减缓了秋冬季节的结冰速度。尽管受雪厚影响,多年冰上层热传导通量与气温依旧具有很好的线性关系,气温每降低1℃,热传导通量增加约0.59 W/m2。 相似文献
18.
This study addresses the impact marshes have on the dissolved oxygen content of tidal waters, particularly during summer when respiratory demand for oxygen in adjacent coastal waters is at a maximum and the solubility of oxygen is lowest. The net transports of dissolved oxygen, salt and heat have been measured for 65 tidal cycles during late spring and summer for a small (0·14 km2) salt marsh basin near North Inlet, S.C. The results indicate that export of dissolved oxygen occurs only on tidal cycles that begin between 2:00 am and 10:00 am such that high tide occurs within 4 h of noon. The largest exports of oxygen and heat are produced by spring tides beginning near sunrise. Although the time window for oxygen export is only about 8 h in duration, there is a more or less overall long-term balance between export and import because the magnitude of oxygen export is about 25% greater than import. The magnitude of heat export similarly exceeds heat import but because the time windows for heat export and import are equal, there is an overall export of heat. This study thus suggests that in summer salt marshes of the Atlantic coast export heat and are in balance with respect to the export and import of dissolved oxygen. However, because of the interaction of the diurnal tide with the daily cycle of solar radiation, transient dissolved oxygen concentrations in tidal waters can range from 1.5 to 10.0 ppm. Thus loading of additional oxygen consuming materials to these waters possibly could lead to significant periods of anoxia. 相似文献
19.