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太湖水体光学衰减系数的特征及参数化 总被引：34，自引：3，他引：34
利用2001-2002年周年太湖全湖不同湖区湖泊光学及表层水样的实测资料，分析了太湖水体表层光学衰减系数与透明度、无机和有机颗粒物质及叶绿素a的相关关系，建立了表层水光学衰减系数与无机、有机颗粒物质及叶绿素a多元线性回归方程。结果表明，光学衰减系数与透明度的关系为：Kdg0.096 1.852/ST；表层水光学衰减系数与无机、有机颗粒物质及叶绿素a多元线性回归方程为：Kd=0.219 0.0768Ciss 0.214Cdet 0.006Cchl；光学衰减系数变化的主要影响因子是无机及有机颗粒物。 相似文献
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长江口及邻近海域浮游植物现存量的上下行控制分析 总被引：2，自引：0，他引：2
利用2010—2011年度3个季节的调查资料以及广义相加模型(GAM)分析,研究了长江口及邻近海域浮游植物现存量(以叶绿素a浓度表征)的上下行控制作用。调查结果显示,在叶绿素高值区,三航次营养盐含量均比整个海区平均值偏低,且春季呈现三季节最低的磷酸盐(PO4-P)和硅酸盐(SiO3-Si)浓度(平均值分别为0.48和8.96μmol/L)以及最高的氮磷比(DIN/P为43.3),为该海域春季甲藻赤潮频发提供了有利条件。夏季叶绿素高值区的硅氮比(Si/DIN)相对整个调查区较高,而春季和秋季却相近,这与夏季藻华种类主要是硅藻相一致。春、夏两季叶绿素高值区的悬浮物浓度(TSS)在时空比较上均显著低值。浮游动物高值区分布与叶绿素高值区分布虽不完全重合,但有交叉或两者相邻。GAM模型分析结果显示,各环境因子变化对长江口及邻近海域叶绿素变化的贡献可达70%以上,且主要影响因子为盐度和营养盐,而与TSS、浮游动物生物量和温度三因子的直接相关性不显著(p0.05)。受长江冲淡水的影响,盐度与DIN、PO4-P、SiO3-Si、TSS等因子间存在显著的相关关系(p0.001),说明盐度对叶绿素变化的影响可能体现了营养盐和光照条件等因子的作用。上述研究结果表明,在长江口及邻近海域,营养盐的上行效应是浮游植物现存量的主要控制作用,而光照条件和浮游动物生物量与浮游植物现存量虽然在时空分布上存在一定的联系,但非决定性控制因素。 相似文献
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渤、黄、东海透明度的分布与变化 总被引：6，自引：1，他引：6
本文根据1972～1987年间中国和南朝鲜的海洋调查资料,分析研究了渤、黄、东海海水透明度的分布特征和季节变化,并对其影响因子作了较为详细的讨论。渤、黄、东海海水透明度具有明显的地区差异和季节变化。其基本特征为:近岸和河口区透明度低;远岸和受外海水系影响区高。冬季低;夏季高。控制透明度分布和变化的主要影响因子有:风和潮流的搅拌作用、大陆径流、沿岸和外海流系、沉积物分布和海洋层化等。 相似文献
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大亚湾倾倒区海洋动力对疏浚物扩散的影响分析 总被引：1，自引：0，他引：1
本文利用对大亚湾海洋倾倒区在9个月倾倒期间的跟踪监测数据统计、分析其在接纳疏浚物倾倒期间悬浮物浓度的特征以及变化特点；通过相关系数的计算，分析海洋动力（波浪、海流）对疏浚物扩散的影响．结果显示：海区海洋动力较强，疏浚物扩散快速，因此，大量倾倒时，倾倒区悬浮物浓度并不大幅度上升；海域的波高与倾倒区悬浮物浓度存在显著正相关，即波浪是影响倾倒区浓度的主要因素；海流是疏浚物扩散的主要因子，其作用导致监测海区很少出现高悬浮物浓度．自然状态下，海水的运动状态和悬浮物浓度也在不断变化之中，因此，如何确定海域的悬浮物本底浓度是一个值得进一步探讨的问题． 相似文献
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本文阐述了1982—1983年在渤海综合调查中所作的叶绿素a调查,分析研究了叶绿素a时空变化与环境因子的关系.结果表明,渤海水域叶绿素a的数量分布具有明显的时空变化特征,叶绿素a的变化范围为0.2—8.0mg/m3,其季节变化呈双峰状,高峰期在初春3月,次高峰在秋季9,10月间,初夏6月为低值期,冬季12,1月为一年中的最低期,叶绿素a的垂直分布变化不甚明显,春季叶绿素a最大值出现在5m以上水层中,夏、秋季最大值位于5—10m的水层中,冬季水体中叶绿素a的分布较为均匀,初步得出渤海水域叶绿素a分布的季节变化规律. 相似文献
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大亚湾叶绿素a的分布及其影响因素 总被引：3，自引：0，他引：3
本文主要阐述大亚湾水域叶绿素a含量的分布规律和周年变化特点,并从生态学角度分析和讨论生物或非生物环境,包括温度、透明度、溶解氧、营养盐、浮游生物及鱼类活动等对叶绿素a分布的影响,建立它们之间的相关模式,画出相关图。通过研究,认为海水透明度随叶绿素a含量的变化而变化,两者呈正相关关系;温度和营养盐将是影响叶绿素分布的重要因子。对如何改善大亚湾的生物环境,增强饵料基础,提高水域生产力等问题提出初步见解。 相似文献
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Simultaneous measurements of the diffuse attenuation coefficient, k, and the collinated beam attenuation coefficient, c, were made on a continuous basis at a near-shore site off the north coast of Anglesey, North Wales. A statistical approach to calculating the diffuse attenuation coefficient, k, in coastal waters allowed variations in transparency to be taken into consideration. The ratio of c:k varied throughout the year between approximately 11:1 and 5:1, indicating the changes in the scattering and absorption properties of the water column. The major contribution to coastal turbidity was from the scattering of light by suspended material with the relationship between scattering and absorption being dependent on the nature of the suspended matter. 相似文献
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Sediment and water column data from four sites in North, Central and South San Francisco Bays were collected monthly from November 1999 through November 2001 to investigate the seasonal variation of benthic organic matter and chlorophyll in channel sediments, the composition and quality of sediment organic matter (SOM), and the relationship between seasonal patterns in benthic organic matter and patterns in water column chlorophyll. Water column chlorophyll peaked in the spring of 2000 and 2001, characteristic of other studies of San Francisco Bay phytoplankton dynamics, however an unusual chlorophyll peak occurred in fall 2000. Cross-correlation analysis revealed that water column chlorophyll at these four channel sites lead sediment parameters by an average of 2 to 3 months. Sediment organic matter levels in the San Francisco Bay channel showed seasonal cycles that followed patterns of water column production: peaks in water column chlorophyll were followed by later peaks in sediment chlorophyll and organic matter. Cyclical, seasonal variations also occurred in sediment organic matter parameters with sediment total organic carbon (TOC) and total nitrogen (TN) being highest in spring and lowest in winter, and sediment amino acids being highest in spring and summer and lowest in winter. Sediment chlorophyll, total organic carbon, and nitrogen were generally positively correlated with each other. Sediment organic matter levels were lowest in North Bay, intermediate in Central Bay, and highest in South Bay. C:N ratio and the ratio of enzyme hydrolyzable amino acids to TOC (EHAA:TOC) data suggest that SOM quality is more labile in Central and northern South Bay, and more refractory in North Bay and southern South Bay. 相似文献
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V. I. Man’kovsky 《Physical Oceanography》2012,21(5):305-319
We compute model spectra of the beam attenuation coefficient in surface waters of the Mediterranean Sea. These spectra are
used to determine the contribution of the components of seawater (suspended matter, yellow substance, pigments of phytoplankton,
and pure water) to the beam attenuation coefficient in different types of seawater. For the surface waters, we establish the
relationship between the light scattering coefficient and the attenuation coefficient at a wavelength of 547 nm and determine
the background (limiting minimum) value of the coefficient of absorption by the yellow substance in waters of the Mediterranean
Sea. It is compared with the values of the same parameter for some other basins (Black Sea, Lake Baikal, Baltic Sea, and oceanic
waters). 相似文献
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The beam attenuation coefficient, organic carbon (POC) and organic nitrogen (PON) contents of suspended materials in Etauchi
Bay, which has little inflow of river water as well as very weak tidal current (maximum speed: 6.5cm·sec−1), were measured as a function of depth for all seasons to understand a seasonal variation of bottom turbidity layer. In spring
and summer, the beam attenuation coefficient in bottom layer and POC and PON contents of suspended materials in the surface
water layer increased with time, which brought the occurrence of the bottom turbidity layer. From autumn to winter, however,
their concentrations became low and constant over the whole depth almost independent of time. As a result, the bottom turbidity
layer disappeared in winter and beam attenuation coefficient became constant over the whole depth. From these results, it
may be considered that the bottom turbidity layer was produced by phytodetritus brought from surface water layer, rather than
by resuspension of bottom sediment in Etauchi Bay. 相似文献
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Oceanology - Based on long-term measurements of the concentration of total suspended particulate matter (TSM), particulate organic carbon, chlorophyll a, and the water transparency index for... 相似文献
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Average values of inherent optical properties for the 400–700 nm waveband were estimated from quantum irradiance measurements on 27 New Zealand lakes of diverse optical character, using published nomograms. Secchi disc depths, turbidity, algal pigment, non‐volatile suspended solids, and absorption by membrane‐filtered samples at 440 nm (g 440 ) were also measured. Turbidity (NTU) correlated closely with the scattering coefficient (m‐1) and these quantities were almost numerically equal, as found in other studies. The data were found to conform to an expression in the oceanographic literature relating Secchi disc depth to the beam attenuation and diffuse attenuation coefficients. Specific beam attenuation, scattering, and absorption coefficients were estimated from the coefficients of linear multiple regressions of the measured total coefficients on the variables: total pigment (chlorophyll a + phaeopigment), non‐volatile suspended solids, and g 440. The estimated values were in reasonable agreement with similar specific coefficients reported in the oceanographic literature. The coefficients provide a basis for predicting clarity in new impoundments or for predicting the effects of loading changes (e.g., of nutrients) on the clarity of existing lakes. The coefficients can be used for classifying lake waters into different optical types. 相似文献
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The diffuse attenuation coefficient(Kd) for downwelling irradiance is calculated from solar irradiance data measured in the Arctic Ocean during 3rd and 4th Chinese National Arctic Research Expedition(CHINARE), including 18 stations and nine stations selected for irradiance profiles in sea water respectively. In this study, the variation of attenuation coefficient in the Arctic Ocean was studied, and the following results were obtained. First, the relationship between attenuation coefficient and chlorophyll concentration in the Arctic Ocean has the form of a power function. The best fit is at 443 nm, and its determination coefficient is more than 0.7. With increasing wavelength, the determination coefficient decreases abruptly. At 550 nm, it even reaches a value lower than 0.2. However, the exponent fitted is only half of that adapted in low-latitude ocean because of the lower chlorophyll-specific absorption in the Arctic Ocean. The upshot was that, in the case of the same chlorophyll concentration, the attenuation caused by phytoplankton chlorophyll in the Arctic Ocean is lower than in low-latitude ocean. Second, the spectral model, which exhibits the relationship of attenuation coefficients between 490 nm and other wavelength, was built and provided a new method to estimate the attenuation coefficient at other wavelength, if the attenuation coefficient at 490 nm was known. Third, the impact factors on attenuation coefficient, including sea ice and sea water mass, were discussed. The influence of sea ice on attenuation coefficient is indirect and is determined through the control of entering solar radiation. The linear relationship between averaging sea ice concentration(ASIC, from 158 Julian day to observation day) and the depth of maximum chlorophyll is fitted by a simple linear equation. In addition, the sea water mass, such as the ACW(Alaskan Coastal Water), directly affects the amount of chlorophyll through taking more nutrient, and results in the higher attenuation coefficient in the layer of 30–60 m. Consequently, the spectral model of diffuse attenuation coefficient, the relationship between attenuation coefficient and chlorophyll and the linear relationship between the ASIC and the depth of maximum chlorophyll, together provide probability for simulating the process of diffuse attenuation coefficient during summer in the Arctic Ocean. 相似文献
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1 IntroductionKnowledge of suspended particle size and distri-bution is the key elements for better understandingthe sediment transport processes ( Wang et al.,2004), primary production (Ning et al., 2004),water quality controlling and pollution predictio… 相似文献
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By using the results of simultaneous measurements of the beam attenuation coefficient and the concentration of suspended matter in water samples, we deduce the relationships between these parameters for wavelengths of 640, 660, and 677 nm. The proposed formulas are used for the evaluation of the concentration of suspended matter according to the data of optical measurements performed in cruises of research vessels. We present two maps of the distribution of suspended matter plotted for the north part of the sea in November–December 1991 and for the south part of the sea in July 1992. 相似文献