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1.
基于EOF分析对南海西北海域水体光谱特性的研究 总被引：1，自引：0，他引：1
This study presents an analysis of the spectral characteristics of remote sensing reflectance(R_(rs)) in northwestern South China Sea based on the in situ optical and water quality data for August 2018.R_(rs)was initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole R_(rs) were characterized using the empirical orthogonal function(EOF) analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95% of the variances of R_(rs) are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of R_(rs)(A-D R_(rs)-EOF_1) significantly contributed to the total variances of each R_(rs) class.In addition,the correlation coefficients between the amplitude factors of class A-D R_(rs)-EOF_1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class AR_(rs)-EOF_1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B R_(rs)-EOF_1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(a_g(λ)),whereas the spectral shape of class C R_(rs)-EOF_1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D R_(rs)-EOF_1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape. 相似文献
2.
磷酸盐对两种东海典型赤潮藻影响的围隔实验 总被引：8，自引：0，他引：8
采用了围隔生态实验方法,研究了围隔中营养盐含量及结构变化和磷酸盐对东海典型赤潮藻种(东海原甲藻和中肋骨条藻)生长的影响。结果表明,在高磷条件下,中肋骨条藻快速增殖,稳定期缩短,细胞数很快下降,而东海原甲藻由于氮源的限制生长期明显缩短。在磷限制条件下,中肋骨条藻细胞增殖受到明显抑制,生物量偏低,而东海原甲藻受到的影响较小。磷可能是东海原甲藻及中肋骨条藻生长的限制因子。氮磷比会影响浮游生物的生长,较高的氮磷比可能对东海原甲藻的生长有利,较低氮磷比则可能有利于中肋骨条藻生长。东海原甲藻能在营养盐浓度较低的生长环境中占有优势,相反,营养盐浓度较高的环境更适合中肋骨条藻的生长,中肋骨条藻具有更强的竞争能力。 相似文献
3.
Hong Guangwen 《海洋学报(英文版)》1992,11(2):287-303
An exact analytic solution for wave diffraction by wedge or corner with arbitrary angle (rπ) and reflection coefficients (R0 and Rr) is presented in this paper. It is expressed in two forms-series and integral representations, corresponding recurrence relation and asymptotic expressions are also derived. The solution is simplified for some special cases of rπ. For Rr= R0,r= 1/N and Rr≠R0,r = 1/2N, the solution can be reduced to linear superpositions of incident and partially reflected waves, hence a nonlinear solution of forth order for this problem can be obtained by using the author's theory of nonlinear interaction among gravity surface waves. The given solution is related to inhomogeneous Robin boundary conditions, which include the Neumann boundary conditions usually accepted in wave diffraction theory. 相似文献
4.
利用超高效液相色谱-四级杆-飞行时间串联质谱(UPLC-Q-TOF-MS)对8种海洋硅藻的四种主要光合膜膜脂的分子结构和组成进行了定性定量分析。结果表明,海洋硅藻中MGDG含量最高,占四种光合膜膜脂的40%~70%左右,SQDG其次占10%~40%,而PG在4%~20%之间,DGDG占5%~20%;其中,各脂类分子的含量在0.14~99.79 nmol/mg干藻之间,而C16:3/C16:3-MGDG,C20:5/C16:3-MGDG,C20:5/C16:2-DGDG,C20:5/C16:1-DGDG,C16:1/C16:1-DGDG,C14:0/C14:0-SQDG,C14:0/C16:0-SQDG,C14:0/16:1-SQDG,C14:0/C16:3-SQDG和C18:1/C18:1-PG等脂类分子在8种海洋硅藻的每一类膜脂中均有分布;与高等植物膜脂的脂肪酰基分布不同的是,海洋硅藻的MGDG与DGDG的sn-2位上的脂肪酸全部为C16酸,可推断是通过类似高等植物典型的原核途径合成,而C16酸和C18酸在SQDG和PG的sn-2位上均有分布,可推断SQDG和PG存在原核和真核两种合成途径。 相似文献
5.
通过现场围隔实验，模拟赤潮发生过程，研究了种群不同生长阶段中不同粒级浮游植物种群的变化情况。结果表明，添加营养盐能有效促进浮游植物的生长，东海原甲藻围隔（M1）和自然水体围隔（M2）中浮游植物分别于第7天和第4天出现生长高峰，叶绿素a最大值分别为112．79mg／m和235．60mg/m。微型浮游植物与微微型浮游植物存在竞争，微型对微微型生长的抑制作用：M2〉M1。在营养盐丰富时，硅藻的增殖速率比东海原甲藻快，达到高峰期时间短，消亡也快。硅的减少促进硅藻水华的消亡。 相似文献
6.
浮标测量的光学数据时间序列长、分辨率高, 能可靠地测量快速变化的漫射衰减系数(Kd)。东海赤潮高发区水体中的浮游植物生物量及悬浮泥沙含量存在较大的变化, 光学性质复杂。文章利用2013年9月至2014年1月的海洋光学浮标数据, 获得了该海域水体的表观光学特性, 基于Kd(490)与遥感反射比[Rrs(λ)]的相关关系建立了Kd(490)的经验算法, 并与已有7种反演算法进行了比较。结果表明, 该海域的Kd(λ)及Rrs(λ)具有显著的Ⅱ类水体光谱特征, 其中, Kd(490)的范围为0.01~4.31m-1, 水体的浑浊程度变化大。Kd(490)与Rrs比值的相关性较好, 据此建立了以Rrs(650)/Rrs(510)、Rrs(555)/Rrs(510)作为自变量的Kd(490)双比值经验算法。将新建算法反演获得的Kd(490)与实测Kd(490)相比, 均方根误差、平均相对误差百分比和线性回归的决定系数分别为0.27m-1、27.08%和0.77, 优于其他7种算法。算法精度的提高源于新建算法选择的Rrs能充分反映水体信息, 并适应水体组分的变化, 可为东海赤潮高发区Kd(490)的反演提供较好的选择, 并为海洋光学浮标在水体环境监测中的应用提供示例。 相似文献
7.
Interspecies competition for nutrients between Prorocentrum donghaiense Lu and Skeletonema costatum (Grev.) Cleve in mesocosm experiments 总被引：1，自引：1，他引：0
Three mesocosm experiments were conducted in the East China Sea during blooms of Prorocentrum donghaiense Lu in May of 1998, 2002 and 2003 to examine the role of nutrients in the formation of these harmful algae blooms (HABs). The results showed that there was interspecies competition between P. donghaiense and Skeletonema costatum (Grev.) Cleve. The cell number of P. donghaiense and S. costatum accounted for about 85% and 11% of the total cell number of phytoplankton respectively at the beginning of the experiment in May 1998. In May 2002, at the beginning of the experiment, the cell number of P. donghaiense accounted for 55%—66% of the total and S. costatum accounted for 32%—42%. The density of P. donghaiense and S. costatum was over 95% and 1%—5% respectively in May 2003. The results of these three mesocosm experiments showed that the dominant species in this specific community varied with different nutrient availability. Under lowphosphate conditions, the dominant species was P. donghaiense, while S. costatum became dominant in phosphatereplete cases. The average growth rate (1.08 d-1) of S. costatum in exponential growth phase was higher than that (0.39 d-1) of P. donghaiense. In the mesocosm, S. costatum predominated in the mesocosm by its rapid growth. When phosphorus was depleted, the cell number of S. costatum dropped rapidly, while P. donghaiense Lu decreased more slowly. The results from mesocosm experiment may explain why: (1) P. donghaiense bloom usually occurs in May, when phosphate concentration is low; (2) the bloom of S. costatum appears in early spring and summer time, when nutrients increase with increasing Changjiang River (Yangtze River) runoff; (3) the bloom of S. costatum is short and that of P. donghaiense Lu can last more than a month in the East China Sea. 相似文献
8.
长江口及其邻近海域CDOM光谱吸收特性分析 总被引：3，自引：0，他引：3
研究了长江口及其邻近海域有色可溶性有机物(CDOM)的光吸收特性,分析了CDOM浓度(吸收系数a(440))、光谱斜率(Sg)与盐度的关系。结果表明:长江口及其邻近海域CDOM的a(440)变化范围为0.21~0.85 m-1,平均值为0.44 m-1;Sg值的范围为0.013 3~0.016 7 nm-1,平均值为0.014 nm-1;a(440)的水平分布表现为长江口海区比外海区高,Sg的水平分布表现为长江口海区比外海区低,反映了长江口海区CDOM中的腐殖酸成分比外海区大。研究区内a(440)与盐度、Sg与盐度明显线性相关,表明CDOM在河口混合行为中呈保守行为,CDOM具有良好的保守性质。 相似文献
9.
遥感技术在河口颗粒态总磷分布及扩散研究中的应用初探 总被引：4，自引：0，他引：4
以美国SeaStar卫星装载的SeaWiFS海洋水色遥感传感器作为遥感数据源,实测了光谱、海表温度、悬浮物含量、透明度、叶绿素浓度、颗粒态总磷含量等,建立了传感器悬浮物含量和颗粒态总磷含量的遥感信息提取模式,结果表明:(1)利用遥感技术估算的海水悬浮物的平均相对偏差为18.1%;(2)悬浮物在遥感图象上的分布和扩散趋势与实际吻合,并且在一定程度上反映了区域内海流运移路径;(3)颗粒态总磷含量在长江河口和杭州湾附近海域较高,由近岸向远岸迅速降低,与实际分布相符;(4)模型主要适用于河口等悬浮物含量高的Ⅱ类水休,对于以浮游植物为主的Ⅰ类水体应另外建立模式. 相似文献
10.
在添加浒苔和紫菜干体的条件下,通过测定藻细胞数量,观察藻细胞形态,分析海藻干体对米氏凯伦藻、中肋骨条藻和塔玛亚历山大藻的半抑制和完全抑制浓度以及半抑制和完全抑制浓度有效作用的起始藻细胞数量范围,研究了浒苔和紫菜干体对3种赤潮微藻生长的影响.在此基础上,设定海藻干体的添加量为其完全抑制浓度,通过监测微藻培养液中总氮(硝酸态氮、氨态氮和亚硝酸态氮)和总磷等变化,分析海藻干体添加对培养液营养化程度的影响.结果表明:(1)当浒苔和紫菜干体浓度分别大于0.8 g/L 和1.0 g/L 时,海藻干体能显著抑制3种赤潮微藻的生长,它们对赤潮微藻的生长抑制率超过60%(第12 d).(2)浒苔和紫菜干体对3种实验微藻的半抑制浓度(IC50)接近,在0.71~1.22 g/L 之间;但完全抑制浓度(IC10)差别较大,浒苔干体对3种赤潮微藻的完全抑制浓度在2.4~2.8 g/L 范围,其数值约为紫菜干体对它们的完全抑制浓度的2倍.(3)3种赤潮微藻起始藻细胞数量不超过40伊104·mL-1(对于米氏凯伦藻和中肋骨条藻来说,起始藻细胞数量可增大至60伊104·mL-1),海藻干体对3种实验微藻的半抑制浓度和完全抑制浓度均有效.(4)添加海藻干体的实验组培养液中总氮和总磷含量均明显高于对照培养液中总氮和总磷含量.其中,实验组培养液中总氮浓度为382滋g/L,总磷浓度明显低于100滋g/L.综上所述,浒苔和紫菜干体具有强烈的抑藻作用,且不会造成培养液营养加剧现象,可尝试应用于赤潮微藻的控制与治理中. 相似文献
11.
于2019年3月、7月和10月对长江口及邻近海域有色溶解有机物(CDOM)的分布及河口混合行为进行分析研究。通过对盐度、吸收光谱斜率S275～295、吸收系数aCDOM(355)以及叶绿素a的分析发现,在河口内低盐度区,7月淡水流量大,陆源输入量最大,aCDOM(355)值最高,3月CDOM来源主要受陆源输入和浮游植物生产活动的影响,aCDOM(355)值较10月高;在口外高盐度区,3月和7月的aCDOM(355)值相近,均低于10月,CDOM分布主要受浮游植物生产活动的影响。利用三维荧光光谱?平行因子分析方法共鉴定出4个荧光组分:类蛋白质组分C1(280/330 nm)、类腐殖质组分C2(300/350 nm)、类腐殖质组分C3(260/465 nm)和类腐殖质组分C4(320/410 nm)。在3月、7月及10月,4个荧光组分强度由长江口内到口外呈递减趋势,受陆源输入和浮游植物生产活动的影响,平均荧光强度的季节变化总体上来说,由大到小依次为7月、10月、3月。3个季节CDOM荧光组分均存在偏离理论稀释线的现象,说明CDOM的来源(陆源输入、沉积物再悬浮和现场生物活动)和去除(被颗粒物吸附、光降解和细菌降解)机制复杂多变,揭示了长江口区域CDOM在不同时空下的不保守混合行为。 相似文献
12.
13.
Abstract. Coastal Patagonian sea waters had been differentially nutrient-enriched to determine (i) the magnitude of the algal biomass supported and (ii) which species were able to best compete for the available nutrients. Nitrogen was found to be the nutrient limiting growth of the natural phytoplankton population. The addition of NO3 at 25 μg at 1-1 led to a 10 to 30 μg 1-1 increase in chlorophyll a in all but those treatments containing trace metal additions. The best yield coefficients were obtained when a chelator (EDTA) was added with NO3 . A pool of nine diatom species were common in the N03 supplemented waters and the addition of vitamins along with NO3 allowed two of the nine species to dominate. 相似文献
14.
以粤港澳大湾区中山市及其邻近水域河网水体为试验区, 同步采集现场光谱及水质数据, 研究受测水体的高光谱反射率特征, 并分析非光学活性参数中化学需氧量(CODCr)、总磷(TP)浓度与高光谱反射率的相关性。结果显示, 各河流水体光谱反射率主要受悬浮颗粒物和叶绿素a的影响; 在500~680nm波段范围内, 水体光谱反射率大小与CODCr、TP浓度呈负相关关系; 与单波段相比, 特定波段的反射率比值与CODCr、TP浓度值的相关性较高, 与CODCr、TP浓度值相关性最高的反射率比值波段组合分别为R675/R794、R690/R815。选择上述波段组合建立的水质反演模型具有良好的估算精度, 模型估算平均相对误差分别为27.2%、32.1%, 表明高光谱技术在珠江口河网水体非光学活性参数CODCr、TP浓度反演上具有较大的应用潜景。 相似文献
15.
An optical model for the remote sensing of coloured dissolved organic matter in coastal/ocean waters 总被引：2，自引：0，他引：2
An optical model is developed for the remote sensing of coloured dissolved organic matter (CDOM) in a wide range of waters within coastal and open ocean environments. The absorption of CDOM (denoted as ag) is generally considered as an exponential form model, which has two important parameters – the slope S and absorption of CDOM at a reference wavelength ag(λ0). The empirical relationships for deriving these two parameters are established using in-situ bio-optical datasets. These relationships use the spectral remote sensing reflectance (Rrs) ratio at two wavelengths Rrs(670)/Rrs(490), which avoids the known atmospheric correction problems and is sensitive to CDOM absorption and chlorophyll in coastal/ocean waters. This ratio has tight relationships with ag(412) and ag(443) yielding correlation coefficients between 0.77 and 0.78. The new model, with the above parameterization applied to independent datasets (NOMAD SeaWiFS match-ups and Carder datasets), shows good retrievals of the ag(λ) with regression slopes close to unity, little bias and low mean relative and root mean square errors. These statistical estimates improve significantly over other inversion models (e.g., Linear Matrix-LM and Garver-Siegel-Maritorena-GSM semi-analytical models) when applied to the same datasets. These results demonstrate a good performance of the proposed model in both coastal and open ocean waters, which has the potential to improve our knowledge of the biogeochemical cycles and processes in these domains. 相似文献
16.
海洋中光后向散射系数的变化包含了浮游植物生物量的信息, 可应用于卫星遥感和光学剖面观测平台获取海洋中大时空尺度-高分辨率剖面的浮游植物生物量变化特征。本文选取了琼东上升流影响下生物—光学变异性较为显著的海域, 基于2013年航次实测数据, 建立了颗粒物后向散射系数(bbp)与叶绿素a浓度(Chl a)间的区域性关系模型。模型假定颗粒物后向散射系数由不随叶绿素浓度变化的固定背景值, 以及较大粒级(>2μm)和pico级(微微型, <2μm)两类浮游植物的后向散射贡献累加所得。采集的数据集进行了模型检验, 结果表明, 模型能很好地模拟琼东海域水体的bbp与Chl a间的变化趋势, 性能优于常用的幂函数关系模型, 尤其在低叶绿素浓度范围, 很好地解决幂函数显著低估的现象; 琼东海域的bbp和Chl a关系存在显著的水层变化, 底层后向散射固定背景值显著高于上层水体背景值, 表明底层受上升流的影响, 水体中不随Chl a共变的颗粒物浓度增大, 其后向散射相应增强; 叶绿素最大层的后向散射固定背景值显著低于上层其他水体的固定背景值, 后向散射固定背景值的贡献百分比约为21%~35%; 随着叶绿素浓度增大, 较大粒级的浮游植物对颗粒物后向散射系数的贡献也显著增大, 可达到50%以上, pico级浮游植物贡献稳定在40%附近。本研究的结果将为琼东海域浮游植物生物量的光学遥感、生物地球化学过程研究提供更为精确的区域性模型和基础支撑数据。 相似文献
17.
A late Pliocene diatom Ge/Si record from the Southeast Atlantic 总被引：1，自引：0，他引：1
As a result of both culture and sediment core studies, the ratio of germanium (Ge) to silicon (Si) in diatom shells has been proposed as a proxy for monitoring whole-ocean changes in seawater Ge/Si, a ratio affected by changes in continental weathering. However, because of the difficulties of extracting and cleaning diatom frustules from deep-sea sediments, only samples from highly pure diatom oozes in the Antarctic region have been previously analyzed. Here we present data on diatom Ge/Si ratios, (Ge/Si)opal, for the time interval between 3.1 and 1.9 Ma from a mid-latitude, coastal upwelling area where significant terrigenous sediment input complicated the sample processing and analyses. In general, our (Ge/Si)opal values show the same decreasing trend after 2.6 Ma than previously measured in Antarctic sediments (Shemesh et al., 1989. Paleoceanography 4, 221–231), but with a noisier background that may reflect the local imprint of proximal continental input superimposed upon global changes in the ocean reservoir. The time of initiation of large-scale North Hemisphere glaciation at 2.6 Ma is characterized by a declining pattern of diatom Ge/Si ratios, which could have resulted from a global increase in the input of riverine Si due to enhanced silica weathering and/or equatorward (northward) intrusions of subantarctic waters enriched in silica. High (Ge/Si)opal ratios are associated with high opal contents from the same sediment samples and with warm climate as indicated by depleted benthic foraminiferal δ18O values from the North and Equatorial Atlantic. Cold periods signified by enriched benthic δ18O values, on the contrary, are associated with lower (Ge/Si)opal ratios. We interpret diatom Ge/Si values to reflect the prevailing weathering state on the continents, with greater chemical weathering during warm and wet periods of the Pliocene and less during cooler and drier intervals. 相似文献
18.
The concentration and partition ratio of various speciations of nutrients in domestic sewage were determined. The transformation and transportation among the speciations, as well as their biological effects during sewage-seawater mixing were simulated in laboratory. The results are compared with field observation and the following findings are: i) The suitable range of ratio DIN/DIP in seawater for growth of phytoplankton in subtropical estuary and harbor is quite wide. It could grow well even in the range of 15-55 in atom ratio, and is independ of the variation in levels of N and P. ii) The transformation rate among the speciations of phosphorus is within the range of 0. 5 to 1. 1 μmol/d . iii) Phytoplankton uptakes P prior to N during its growth. The growth rate for Skeletonema costatum (the major species) and field algae are 0. 34-0. 58/d and 0. 30-0. 31/d, respectively. iv) The red tide species Prorocentrum micans could become the dominant species to a density 107 cells/L after Skeletonema costatum 相似文献
19.
The ERG-determined scotopic spectral sensitivity (Sλ) curve of the intact anesthetized cuttlefish Sepiella maindroni de Rochebrune attains its major peak at 490 nm with no secondary peak. In adaptation to white or colour light of different intensities, both peak and shape of S λ curve have no change. It is suggested that only one receptor system is present in the retina of cuttlefish, as a result, its colour-discrimination ability appears to be lacking. 相似文献
20.
大亚湾澳头海域硅藻、甲藻的数量变动及其与环境因子的关系 总被引：12，自引：1，他引：11
于1997年7月-1998年6月采集大亚湾澳头海域水样,根据《海洋监测规范》分析调查方法,研究了硅藻和甲藻的数量变动及其与环境因子之间的关系,共鉴定出浮游植物198种,其中硅藻98种,甲藻83种。结果表明,大亚湾浮游植物细胞密度较高,年平均细胞密度为424．7cells／ml,最高细胞密度为6689．8cells／ml,硅藻为浮游植物的主要类群。调查期间共发生藻类水华7次,硅藻可在全年各季节发生水华,而甲藻水华仅在春季发生。硅藻水华的消退与N的大量消耗有关,而甲藻水华对P消耗较大。结果表明,大亚湾合适的温度、盐度、气象条件、丰富的硅酸盐含量及N、P等营养盐的及时补充是大亚湾浮游植物数量高和水华频繁发生的主要原因,同时风、流等物理因素对藻类的聚积作用对水华的发生也有一定的促进作用。 相似文献