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东海及外缘海域月平均表层海水温度场变化的持续性较好,正温度距平场最长可持续18个月,负温度距平场可持续14个月。能谱分析结果表明,由于该区受黑潮暖流系统的控制,存在明显的6、7年周期。 文中给出了几种以数理统计为基础的表层水温场预报方法,即单要素和多因子的经验正交场分解时间序列预报方法,对东海及外缘海域月平均表层海水温度场进行了连续6年(1978-1983)的实时预报,其效果比较稳定,预报误差较小,从1978～1983年的平均预报误差为0.53℃。 相似文献
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西北太平洋海气界面热通量时空分布特征研究 总被引：2，自引：0，他引：2
基于第三版本HOAPs (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data)海表面温度、潜热通量、感热通量、海表面空气比湿以及海表面风场5个参量的18 a(1988～2005年)逐月平均资料,利用经验正交函数和奇异值分解方法分析了异常潜热和感热通量场在西北太平洋的时空分布特征及造成这种分布的主要影响因素.EOF的分析结果表明,异常潜热通量场主要体现为第一第二两个模态的变化,第一模态显示整个海域呈同相变化且在时间上呈准年周期变化,第二模态则描述了分别位于10°N,25°N和40°N的3个极值中心并伴随多年振荡,由因子载荷分布可知热带太平洋是第二模态的行为中心,因此该模态可能与ENSO事件相关.异常感热通量场则主要表现为第一模态的变化,在时间上呈准年周期变化并伴随有多年时间尺度的振荡.奇异值分解方法的分析结果表明异常海表面风场是异常潜热和感热通量场时空变化的重要影响因素. 相似文献
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苏育嵩 《中国海洋大学学报(自然科学版)》1989,(Z1)
现行的场预报方法,一般是根据预报量之间的统计关系,进行场分解,而后用经验正交函数建立预报方程,但却很少考虑到外界因子的作用。本文尝试把影响因于引入经验正交预报方法中。在这种优选因子场预报方法中,作者不仅考虑预报量之间内部的相互关系,而且也考虑了外部因子的影响,借助于从综合因子中优选因子,可以建立对于预报数量和等级都适用的最优预报方程。提出了权重相关系数的概念。与其他相关系数之间的明显差别是,它具有场的特征。本文还介绍了水湿的盐度预报的一些实例。 相似文献
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苏育嵩 《中国海洋大学学报(自然科学版)》1979,(2)
经验正交分解与标准正交多项式最初同为因子统计组合的一种有用工具,由于经验正交分解收敛性较好,在场的统计组合过程中,又不必像正交多项式那样要求正规的网格点,使用方便。因此,目前经验正交分解法在因子场统计组合、动力模型参数化,以及因子时间序列分析中已得到广乏应用。然而,这两种统计组合法本身都不能直接构成 相似文献
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Two kinds of the empirical orthogonal function analysis method for decomposing the mean-field are developed and a comparison is made between them. It is proved that the mean-field can be decomposed using eigenvectors obtained from anomaly-field decomposition, and that more information can be obtained. An example of sea bottom mean temperature analysis shows its remarhabk effect in depicting the distribution features of variousfactors, such as cold water mass, currents and radiation.A few problems concerning the efficiency of the method are discussedand two matrices of relationship which represent the space-time characteristics of the field are derived. The formulae of space-time transformation are obtained conveniently. 相似文献
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Two kinds of the empirical orthogonal function analysis method for decomposing the mean-field are developed and a comparison is made between them. It is proved that the mean-field can be decomposed using eigenvectors obtained from anomaly-field decomposition, and that more information can be obtained. An example of sea bottom mean temperature analysis shows its remarkable effect in depicting the distribution features of various factors, such as cold water mass, currents and radiation.A few problems concerning the efficiency of the method are discussed and two matrices of relationship which represent the space-time characteristics of the field are derived. The formulae of space-time transformation are obtained conveniently. 相似文献
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基于相关矩阵特征向量的目标分解将地物回波复杂的散射过程分解成相互独立的三种单一散射分量:单向散射、双向散射和交叉散射,分别对应各自的目标相关矩阵。目标分解技术降低了散射回波之间的相关性,有利于分析地物散射机理,有助于提高分类精度。对荷兰F levoland地区全极化数据进行分解,经过试验和相关性分析,选用7种数据形成多参数数据组合,对其进行最大似然监督分类,同时进行常规三种极化加相位差的分类和基于复W ishart分布的最大似然分类,逐像元计算混淆矩阵,分析对比三种分类结果的精度,试验表明:相对于常规数据组合分类,基于复W ishart分布的监督分类可以小幅度提高分类精度,而利用目标分解得到多参数组合数据进行分类则有大幅度的提高。 相似文献
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采用二维小波变换与多尺度分解技术,对南黄海布格重力异常进行了分解,得到了自地表至莫霍面深度范围的不同尺度的密度体所产生的重力异常,从而获取不同切割深度的断裂构造、沉积基底及莫霍面所产生的重力异常。结果表明：该区断裂相互交错、切割深度不一,有明显的多期活动的迹象;小波变换的四阶异常细节主要由沉积基底面起伏所引起的,而小波变换四阶异常逼近主要反映了该区莫霍面起伏特征。 相似文献
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实现了用于平面离散向量场分解的Polthier算法,提出了“先分解向量场,后检出特征”的、基于向量场分解的提取与可视化平面流场中的涡旋、特别是弱小涡旋的新途径. 相似文献
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长江口潮滩先锋植物藨草腐烂分解过程研究 总被引：6，自引：0，他引：6
以长江口崇明东滩湿地为研究区域,采集了先锋植物藨草(Scirpus triqueter)的地上茎和地下根部分,分别埋藏于高潮滩和堤内两处不同地点,研究了植物不同部位组织在腐烂分解过程中质量及其碳、氮元素含量的变化,分析了影响植物分解的主要因素。结果表明,藨草残体在为期391 d的分解过程中质量损失了46%~66%,其中藨草茎分解速率大于藨草根的,高潮滩的大于堤内的;碳含量呈持续降低趋势,而氮含量则显著升高。植物体中初始营养盐水平和C/N比值的高低可能是导致藨草根、茎残体的分解速率存在差异的最主要因素。环境因素(如温度、湿度等)对藨草残体的腐烂分解有着十分重要的影响,温度升高、湿度增大,则加速微生物对植物碎屑的分解。由于受潮汐作用影响,高潮滩的植物埋藏环境比堤内的更潮湿,从而使得藨草在高潮滩的分解速率以及碳、氮元素含量的变化速率都明显高于堤内。 相似文献
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The aim of this study was to investigate nitrogen and phosphorus released in the process of the decomposition of giant jellyfish in the laboratory and found the evidence to verify the influence of nutrients released by the decomposition of jellyfish on the ecosystem in the field. The release of nitrogen and phosphorus from the decomposition of Nemopilema nomurai was examined in a series of experiments under different incubation conditions such as different p H values, salinity values, temperatures and nitrogen and phosphorus concentrations. The results showed that the complete decomposition of Nemopilema nomurai generally took about 4–8 d. The release of nitrogen and phosphorus from the decomposition of Nemopilema nomurai could be divided into two stages: the early stage and the later stage, although the efflux rate of nitrogen was one order more than phosphorus. In the early stage of the decomposition of Nemopilema nomurai, the concentrations of dissolved nitrogen, dissolved phosphorus, total nitrogen and total phosphorus in seawater increased rapidly, and the concentration of nitrogen could reach the highest level in the whole degradation process. In the later stage of the decomposition, the concentrations of dissolved nitrogen and total nitrogen declined slowly, while the concentration of phosphorus in water could reach a maximum in the degradation process. High p H, low salinity,high temperature and N/P will promote the release of nitrogen; low p H is unfavorable to the release of nitrogen but favorable to the release of phosphorus. In addition, we found the concentrations of ammonium and phosphate in the bottom water were higher than those in the surface water during the period of jellyfish bloom in the Jiaozhou Bay, proving that nutrients released by the decomposition of jellyfish have significant influence on nitrogen and phosphorus in the field. For the whole Yellow Sea, nutrients released by jellyfish carcasses may reach up to(2.63±2.98)×107 mol/d of dissolved nitrogen(DN) and(0.74±0.84)×106 mol/d of dissolved phosphorus(DP) during the period of jellyfish bloom. The values are comparable to riverine inputs in a day, but much higher than sediment–water exchange flux in the Yellow Sea. The great amounts of nutrients must have significant influence on the nutrients balance of the Yellow Sea during the period of jellyfish dead and decomposition. Both the experimental data and field observations proved that the decomposition of jellyfish may release a great amount of nutrient to the surrounding environment during the period of jellyfish decomposition. 相似文献
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经验模态与小波分解在光学遥感内波参数提取中的应用 总被引：2，自引：0，他引：2
内波遥感参数提取是利用遥感影像研究海洋内波的重要手段,通过提取内波的基本参数可以对海洋内波的生成与传播机制进行进一步的研究。提出了利用经验模态分解、小波分解与高阶多项式拟合从光学影像中提取内波半波宽度的方法。经验模态分解与小波分解对内波剖面数据进行尺度分解,根据归一化方差最大来提取内波分量;多项式拟合基于内波剖面的亮暗条纹变化完全由内波调制的假设,对数据进行拟合,并根据一阶导数来提取半波宽度。用南海北部东沙岛附近2004年7月10日的中-巴资源卫星(China-Brazil Earth Resources Satellite,CBERS)影像对方法进行了验证。结果表明,3种方法能较好地提取所需参数,获取的内波半波宽度具有较好的一致性;上述方法在处理非平稳及非线性遥感数据上,具有非常明显的优势。基于一维非线性内波理论,通过提取的内波半波宽度,辅以水深和混合层深度数据,反演了内波的振幅。 相似文献