偏振激光散斑的相关性研究     

冯一丁 《中国海洋大学学报(自然科学版)》1994,(3)

采用发送一束线偏振激光产生散斑的方法，研究线偏振激光散斑、＂平均椭圆偏振＂激光散斑以及非偏振激光散斑的相关性和精细结构。指出：当漫射器为一片毛玻璃时，散斑激光是线偏振的．其方向与入射激光束相同；当漫射器为涂无光白漆的毛玻璃时，散斑激光是部分或全部退偏的，涂层越厚，退偏越甚。对于强线偏振散斑场，当偏振方向改变时，散斑的精细结构无明显变化，即使是两个正交方向上的散斑图，也保持良好的相关性。对于非偏振散斑场，当照明激光束的偏振方向改变时．散斑精细结构有明显变化。  相似文献   

Estimating the underwater light field from remote sensing of ocean color     

Cheng-Chien Liu  Richard L. Miller  Kendall L. Carder  Zhongping Lee  Eurico J. D’Sa  James E. Ivey 《Journal of Oceanography》2006,62(3):235-248

We present a new approach that incorporates two models to estimate the underwater light field from remote sensing of ocean color. The first employs a series of analytical, semi-analytical, and empirical algorithms to retrieve the spectrum of inherent optical properties (IOPs), including the absorption and the backscatter coefficients, from the spectrum of remote sensing reflectance. The second model computes the profile of photosynthetically available radiation E _0,PAR (z) for a vertically homogeneous water column using the information of the retrieved IOPs and the ambient optical environment. This computation is based on an improved look-up table technology that possesses high accuracy, comparable with the full solution of the radiative transfer equation, and meets the computational requirement of remote sensing application. This new approach was validated by in situ measurements and an extensive model-to-model comparison with a wide range of IOPs. We successfully mapped the compensation depth by applying this new approach to process the SeaWiFS imagery. This research suggests that E _0,PAR (z) can be obtained routinely from ocean-color data and may have significant implications for the estimation of global heat and carbon budget.  相似文献   

Artificial Upwelling of Deep Seawater Using the Perpetual Salt Fountain for Cultivation of Ocean Desert     

Shigenao Maruyama  Koutaro Tsubaki  Keisuke Taira  Seigo Sakai 《Journal of Oceanography》2004,60(3):563-568

Deep seawater in the ocean contains a great deal of nutrients. Stommel et al. have proposed the notion of a “perpetual salt fountain” (Stommel et al., 1956). They noted the possibility of a permanent upwelling of deep seawater with no additional external energy source. If we can cause deep seawater to upwell extensively, we can achieve an ocean farm. We have succeeded in measuring the upwelling velocity by an experiment in the Mariana Trench area using a special measurement system. A 0.3 m diameter, 280 m long soft pipe made of PVC sheet was used in the experiment. The measured data, a verification experiment, and numerical simulation results, gave an estimate of upwelling velocity of 212 m/day. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Sugar and Lipid Components in Sea Foam near Kelp Beds     

Branko  Velimirov 《Marine Ecology》1982,3(2):97-107

Abstract. A component analysis of the sugar and lipid fraction in foam layers around kelp beds on the South African west coast showed the following trends: In the residue of foam drainage of both 12 h and 120 h old foam the sugar fraction is represented by mannose (33–41 %), galactose (4–30%), fucose (3–29%) and glucose (19–26%). With the exception of fucose, the same components could be found in foam filtration. In the lipid fraction the main fatty acids are palmitic (23.3–27.3%), oleic (14.0–5.5%) and timnodonic acid (11.2–9.1%). Selacholeinic acid was only found in 12 h old foam while lignoceric acid could not be located in foam filtration. Against expectation mannitol was not identified in quantifiable amounts in foam samples although it is the dominant component of kelp mucilage, whose presence is of major importance for foam formation. Hypotheses explaining the lack of mannitol are forwarded. Component sugar and lipid content for 11 of foam was calculated and estimation of sugar and lipid content in an average foam patch (volume of 30001) is given. The importance of foam formation as a mechanism for binding and transfer of energy in the marine environment is emphasized.  相似文献   

Air-Sea Gas Transfer Velocity in Stormy Winter Estimated from Radon Deficiency     

Hitoshi Kawabata  Hisashi Narita  Koh Harada  Shizuo Tsunogai  Masashi Kusakabe 《Journal of Oceanography》2003,59(5):651-661

Thirteen vertical profiles of ²²⁶Ra and ²²²Rn in the near-surface water were obtained in the western North Pacific in winter, and the gas transfer velocities across the air-sea interface were estimated. The transfer velocities found by applying a steady state model varied widely from 2.1 to 30.2 m day⁻¹ with a mean of 9.4 m day⁻¹. The mean value is almost 5 times higher than that in summer in other oceans, and the maximum value is a record high for world oceans. This is partly due to the inadequacy of the steady state model, which overestimates when stronger winds blow in more recent days than the ²²²Rn half-life of about 4 days. In fact, a strong low pressure zone passed through the station about 2 days earlier, which was one of the low pressure zones that with a period of develop once a week or so in the northwestern North Pacific in winter. Instead of steady-state removal, if half of the radon removal occurred sporadically every 7 days, and the last removal took place two days before the observation, the transfer velocity would be 26 m day⁻¹. Our mean transfer velocity, which is less than 20% different from the steady state value including both overestimated and underestimated values, 9.4 ± 4.8 m day⁻¹, seems to represent the mean state of this region in winter. This suggests that the gas exchange fluxes under extremely rough conditions in the open ocean are larger than those estimated by using a transfer velocity equation with a linear or quadratic relationship with wind speed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The trophic spectrum: theory and application as an ecosystem indicator     

Gascuel  Didier; Bozec  Yves-Marie; Chassot  Emmanuel; Colomb  Audrey; Laurans  Martial 《ICES Journal of Marine Science》2005,62(3):443-452

  相似文献   

青岛近海地区SO2和SO42-干沉降速率的季节变化     

王泽杰  祁建华  于丽敏  高会旺 《海洋湖沼通报》2006,(4):86-93

用小麦岛和团岛观测站提供的青岛近海气象和水温资料,以适于SO2气体和硫酸盐(SO42-)气溶胶的干沉降模型研究了模型中的输送阻尼对两种污染物质干沉降速率的贡献,并计算了2003年青岛近海地区两种污染物质干沉降速率的季节变化。结果表明:对SO2而言,粘性副层传输系数对沉降速率的贡献大于空气动力学传输系数;对于SO42-,空气动力学传输系数对沉降速率的贡献要大于表面传输系数。SO2和SO42-的干沉降速率变化范围分别为0.187~0.868cm/s和0.188~0.532cm/s。两种污染物质干沉降速率的四季变化有相似的规律,即冬季>秋季>春季>夏季。  相似文献   

Management implications of interactions between fisheries and sandeel-dependent seabirds and seals in the North Sea   总被引：4，自引：2，他引：4  

Furness  Robert W. 《ICES Journal of Marine Science》2002,59(2):261-269

  相似文献   

九龙江河口区磷的转移和入海通量   总被引：1，自引：3，他引：1  

陈松  廖文卓  骆炳坤  许爱玉 《台湾海峡》1996,15(2):137-142

1992～1993年4个航次的调查研究结果表明，九龙江河口区总磷的分布和转移受悬浮物含量明显控制。当SPM含量低时，其迁移过程接近理想行为；SPM含量高时则为非理想行为。估算得出，九龙江水体总磷的平均人海通量为1．47×103t／a。其中，溶解态磷为0．43×103t／a，约占29％；颗粒态磷占71％，九龙江水磷的输入以颗粒态为主。溶解态磷的分布，基本上在某一水平上了波动，其入海通量受环境影响很小，可能意味着颗粒磷的缓冲作用。  相似文献   

利用AMSR-E对台风"泰利"的初步分析   总被引：3，自引：0，他引：3  

刘松涛  严卫  王举 《热带海洋学报》2006,25(5):26-30

基于洋面上的微波辐射传输模型,采用多元线性回归算法,建立了海洋-大气参数的反演算式,并对其进行了验证。在此基础上,根据AMSR-E的反演结果,对台风“泰利”的发生发展过程进行了初步分析。结果表明,反演算式的精度接近于网上公布的业务产品,反演结果比较符合实际情况;但是由于受到所采用物理模型的限制,反演结果对于强降水区不敏感。  相似文献