山东省城镇天气预报质量评估检验

根据中国气象局全国城镇天气业务产品检验评估报告和山东省预报质量评估系统检验结果,对2007年1月—2015年2月山东省城镇天气预报质量进行了总结分析。结果表明:(1)山东省晴雨(雪)和气温预报准确率、提高幅度均高于全国平均,降水预报准确率低于全国平均,技巧评分处于全国平均水平。(2)山东省内晴雨(雪)、最高气温、最低气温预报准确率最高的区域分别是鲁南、鲁西北和半岛,降水预报准确率半岛和鲁南明显高于鲁中和鲁西北地区。(3)山东省晴雨(雪)预报正确率夏季最低,冬季最高;气温预报准确率春季最低,最高气温预报准确率秋季最高,最低气温预报准确率夏季最高。(4)各市气象台预报相对省气象台指导预报有正的订正技巧,晴雨(雪)预报技巧评分鲁中地区相对偏低。     

MEOFIS平台在渤海湾北部海面气温和风速精细化预报中的适用性分析

基于＂动力-统计＂预报方法的MEOFIS（精细化气象要素客观预报）平台以相关模式预报结果为基础,结合历史实况资料建立预报模型,实现站点的精细化预报.利用2009～2011年的T639模式产品和渤海湾北部相关观测站的数据积累统计建模,并对2012～2013年海面4个季节的气温和风速进行预报统计,对比分析该平台在海面气温和风速预报中的适用性.经客观检验,1℃误差范围内,海面各季节的气温和风速预报准确率均高于陆上的预报;海面日最高、日最低和逐3 h气温预报准确率均超过68%,秋季的日最高气温、逐3 h气温和冬季的日最低气温预报最为理想,准确率分别达86.8%、75.2%和78.9%,春季的气温预报整体不理想;显著性检验结果显示：和T639直接输出的结果相比,MEOFIS在各季节的气温预报中具有明显的订正能力.2 m/s误差范围内,过渡性季节春、秋季的日最大风速预报准确率均超过75.0%,夏季的预报效果较差,但逐3 h风速预报准确率最高,达78.0%,冬季的风速预报效果整体不佳;利用总体平均经验模态分解法（EEMD）对各月逐3 h的海面气温和风速预报误差做滤波处理,结果显示MEOFIS平台对这两要素的预报误差均存在明显的双周震荡波,通过滤波可以提高二者预报的准确率,且气温预报准确率的提高更大.预报偏差和方差小的季节,预报准确率的改善更为理想.     

用客观分析生成中国近海及邻近海域温度盐度格点数据集

利用LEVITUS方法对中国近海及邻近海域历史观测的温度和盐度资料进行客观分析,生成累年各月标准层1/2°×1/2°的格点数据集.文中选择给出一些深度标准层次上的平面等值线图.并用该方法分析船舶观测SST数据,将其分析结果应用于中国近海海表面温度短期数值预报的变分伴随资料同化试验中,表明资料的客观分析对海洋数值模拟和预报的重要性.     

2014年6—8月数值模式产品对山东气温预报的检验分析

为检验不同数值模式产品对山东不同站点2m日最高、最低气温24h预报效果,利用2014年6—8月逐3h的WRF-RUC、En WRF确定性预报、不同集合百分位数、T639、中国气象局下发的T639-MOS解释应用产品以及EC细网格预报进行TS评分、误差等分析。结果表明:EC细网格对内陆最高气温预报准确率最高,En WRF确定性预报次之,EC细网格和T639-MOS对内陆最低气温预报准确率最高。T639和EC细网格分别对沿海最高和最低气温预报准确率最高。对各模式单站气温预报进行最优模式分析发现,对于最高气温预报最优的模式为EC细网格和En WRF确定性预报,分别集中在鲁西南和鲁北、鲁中和鲁东南。对于最低气温预报最优的模式为EC细网格和T639-MOS,T639-MOS主要对鲁中山区预报较好,其他地区两个模式预报效果基本相当。     

应用重力地质法反演马里亚纳海沟地形

根据重力地质法(Gravity Geological Method, GGM),利用6 736个已知水深点数据和卫星测高重力异常反 演了马里亚纳海沟(142^°36^''~147^°18^''E,23^°~27^°N)1^''×1^''分辨率的海底地形,该计算中的密度差常数为1.20 g/cm³。将反演的地形与实测检核水深数据相比,两者较差标准差为152.9 m,平均误差为(±3.0) m,均方差为153.0 m,优于ETOPO1模型和直接把船测水深控制点格网化后的模型。将重力地质法反演的模型、ETOPO1模型、直接格网模型进行功率谱密度分析,结果显示3种模型在中长波地形能量一致,但对于短波地形,重力地质法模型能量高于其他2个模型,说明重力地质法更能描绘细致的海底地形地貌。选取2条测线与重力地质法模型进行对比研究,结果表明重力地质法在海底地形起伏小的区域优于在海底地形起伏较大区域的反演效果。     

精细化要素客观预报中的站点差异性研究

以山东省乡镇级精细化要素预报为例,预报站点由县级123个增至1 561个。在精细化要素客观预报方法开发中,如何处理多量预报站(格)点问题?利用山东省稠密的区域自动站观测资料,通过分析不同站点空间分辨和地形属性的观测要素的统计学差异,研究各种气象要素的站点差异性。结果表明:温度、降水等要素具有明显的局地小气候特征,需要更高空间分辨率的预报站点来捕捉;市区、郊区以及不同高度山区等站点间最低气温各分位数统计值差异均较大,但相关系数较高,且频率分布形态相似;风对地形更敏感,不同测站间相关系数较低,分位数统计值和频率分布形态差异均较大。上述结果可为精细化要素客观预报业务中的站(格)点处理提供理论和技术支撑。     

南沙首次西南季风潮爆发迟早的分析及预报

利用1969～1978年全球网格点逐月海表温度资料、1969～1989年天气图资料和北半球500hPa月平均高度及距平图资料,分析了南沙(5°～12°N、110°～120°E)首次西南季风潮(第一次连续出现2天以上风速≥11m/s的西南风)爆发迟早与其前期北半球的500hPa高度值和海表温度的关系,发现首次季风潮爆发的迟早与4月份东亚沿岸中纬度地区500hPa的高度、3～5月南海和4月日本东部海面的海表温度呈正相关,即高度高、海表温度高,季风潮爆发迟,反之爆发早.并在这基础上归纳季风潮爆发的中、长期预报指标.     

北太平洋150°E～165°E海域柔鱼渔场与表温及水温垂直结构的关系

根据 1998～ 2 0 0 1年 8～ 10月 38°N～ 4 4°N各站点水温和生产数据 ,对 15 4°E～ 15 7°E海域柔鱼作业渔场与表温及水温垂直结构的关系进行了分析。结果认为 ,38°N～ 4 4°N各站点水温结构随时间有较大差异。 8～ 9月 38°N～ 4 4°N各站点在 10 0m以内均形成明显的温跃层 ,10月份随着亲潮势力加强 ,跃层强度有所减弱 ,表层混合水可达 5 0m深 ,其温跃层基本上在 5 0～10 0m间。在 15 0°E～ 16 5°E海域 ,渔获产量主要集中在 4 2°N～ 4 4°N ,盛渔期为 8～ 9月。 8月在4 0°N～ 4 1°N海域温场最适表温为 2 0～ 2 2℃ ,在 4 2°N - 43°N海域为 16～ 19℃ ,在 4 4°N附近海域为 14～ 16℃ ,0～ 5 0m、0～ 10 0m温度梯度为 0 .16～ 0 .2 3℃ /m和 0 .11～ 0 .13℃ /m ;9月渔场最适表温、0～ 5 0m和 0～ 10 0m温度梯度为 15～ 2 0℃、0 .15～ 0 .18℃ /m和 0 .12～ 0 .14℃ /m ;10月为12～ 17℃、0 .11～ 0 .2 0℃ /m和 0 .0 9～ 0 .11℃ /m。灰色关联度表明 ,对作业渔场影响最大的是表温、0～ 5 0m温度梯度、0～ 10 0m温度梯度和纬度 ,其关联度均在 0 .8以上。渔获产量受到众多因素的影响 ,其中捕捞努力量、资源丰度、0～ 10 0m温度梯度和纬度是影响渔获量主要因子。     

南半球平流层大气环流的若干特点

利用欧洲中期预报中心(ECMWF)5°×5°格点场南北半球6层位势高度场资料计算分析了南半球平流层100hPa平均地转西风随纬度的分布特点、平均地转西风季节变化特点、厄尔尼诺年前后西风廓线形态差异计算分析了南半球位势高度对纬向平均的偏差,分析了超长波的分布特征.以上结果均与北半球同期计算结果作了对比比较,指出了南北半球大气环流在这几方面的异同点.     

北太平洋海浪数值预报试验

本文利用美国华盛顿数值天气预报中心(KWBC)的3—5天预报的1000hPa等势面的格点高度场(5°×5°)资料,由“海上风的边界层模式”计算的风场,应用“一个参数的大洋波谱模式”,进行了北太平洋海浪数值预报的试验,试验结果表明,尽管输入风场资料存在一定误差,计算的浪场与3─5天后的实测浪场仍有较好的吻合。     

Sea Levels and Coastal Inundation Due to Tropical Cyclones in Indian Coastal Regions of Andhra and Orissa

Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding.     

Sea Levels and Western Boundary Flow Near a Tectonic Zone in the Northern Pacific

This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake.     

Role of Siliceous Fossil Dissolution in Downcore Variations of Grain Size and Water Content: Western Margin of Clarion-Clipperton Fracture Zone, NE Equatorial Pacific

Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors.     

A Nondestructive Technique for Predicting the In Situ Void Ratio for Marine Sediments

This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner.     

Particulate n-alkanes and fatty acids in the Changjiang river system

Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream.     

Three-Dimensional Geographically Weighted Inverse Regression (3GWR) Model for Satellite Derived Bathymetry Using Sentinel-2 Observations

Current trends of development of satellite derived bathymetry (SDB) models rely on applying calibration techniques including analytical approaches, neuro-fuzzy systems, regression optimization and others. In most of the cases, the SDB models are calibrated and verified for test sites, that provide favorable conditions for the remote derivation of bathymetry such as high water clarity, homogenous bottom type, low amount of sediment in the water and other factors. In this paper, a novel 3-dimensional geographical weighted regression (3GWR) SDB technique is presented, it binds together methods already presented in other studies, the geographically weighted local regression (GWR) model, with depth dependent inverse optimization. The proposed SDB model was calibrated and verified on a relatively difficult test site of the South Baltic near-shore areas with the use of multispectral observations acquired by a recently launched Sentinel-2 satellite observation system. By conducted experiments, it was shown that the proposed SDB model is capable of obtaining satisfactory results of RMSE ranging from 0.88 to 1.23[m] depending on the observation and can derive bathymetry for depths up to 12m. It was also shown, that the proposed approach may be used operationally, for instance, in the continuous assessment of temporal bathymetry changes, for areas important in the context of ensuring local maritime safety.     

Geotechnical Properties of Surface Sediments in the INDEX Area

As a part of the environmental impact assessment studies, geotechnical properties of sediments were determined in the Central Indian Basin. The undrained shear strength and index properties of the siliceous sediments were determined on 20 box cores of uniform dimension collected from various locations in five preselected sites. The maximum core length encountered was 41 cm and most of the sediments were siliceous oozes consisting of radiolarian or diatomaceous tests. The shear strength measurements revealed that surface sediments deposited in recent times (0-10 cm) have a shear strength of 0-1 kPa; this value increases with depth, reaching 10 kPa at 40 cm deep. Older sediments have greater strength because of compaction. Water content varies in the wide range of 312-577% and decreases with depth. The clay minerals such as smectite and illite are dominant and show some control over water content. Wet density, specific gravity, and porosity do not indicate any notable variation with depth, thereby indicating a uniform, slow rate of sedimentation. The average porosity of sediments is 90.2%, specific gravity 2.18, and wet bulk density 1.12 g/cm 3 . Sediments exhibit medium to high plasticity characteristics, with the average plasticity index varying between 105% and 136%. Preliminary studies on postdisturbance samples showed an increase in natural water content and a decrease in undrained shear strength of sediments in the top 10- to 15-cm layer.     

Ferromanganese Nodules and their Associated Sediments from the Central Indian Ocean Basin: Rare Earth Element Geochemistry

The rare earth element (REE) distribution in nine deep-sea ferromanganese nodules and their associated siliceous sediments from the Central Indian Ocean Basin (CIOB) have been studied to elucidate the REE relationship among them. Total REE concentration varies from 398-928 ppm in the nodules and 137-235 ppm in the associated sediments, suggesting two- to four-fold enrichment in the nodules compared to associated sediments. REE of nodules and their associated sediments show a positive correlation, suggesting REE are supplied from a common source such as seawater. The positive correlation between REE of nodules and sediments from the CIOB is contrary to the competitive scavenging of REE between nodules and sediment in the equatorial Pacific Ocean. REEs in the nodules are carried by Fe, P, and Ti, whereas in the sediment they are carried by P and Mn phases. A similar REE fractionation pattern with middle REE enrichment over heavy and light REE in both the nodules and their associated sediment suggest fractionation is independent of REE abundance and their carrier phases.     

Marine Minerals in the Mexican Pacific: Toward Efficient Resource Management

Vast reserves of marine minerals are known to occur within the Mexican Exclusive Economic Zone. These reserves include: (1) heavy mineral placers rich in titanium and iron along the coast of San Antonio del Mar, Baja California and the southern States of Oaxaca and Guerrero; (2) phosphorites, which represent the only source for superphosphate fertilizers along the Pacific coast off the Baja California peninsula and the Gulf of Tehuantepec; and (3) manganese oxide deposits in nodule and crusts located adjacent to the Clarion-Clipperton Zone and containing high concentrations of Cu + Ni + Co (up to 1.9%), which are essential for the steel and super-alloy industries. Few but important efforts toward surveying these deposits have been carried out by Mexican and international researchers. Relevant data generated by these investigations are reviewed here and put together in a single document. Adequate knowledge of Mexican mineral resources is essential for the development of management strategies when offshore mining starts during this century. Thus, the review discusses the economics inherent to ocean mining in Mexico, setting baselines for future exploration and development activities in the Mexican Exclusive Economic Zone.     

Enhanced Acoustic Backscatter Due to High Abundance of Sand Dollars, Dendraster excentricus

Detailed acoustic surveys of benthic sediments were conducted in July 1995 and September 1998 in the vicinity of Humboldt Bay, California. During these surveys, a band of enhanced acoustic backscatter was observed offshore from the bay entrance, approximately parallel to the isobaths, in water depths ranging from 16-24 m. In order to assess the cause of the increase in backscatter levels, a more comprehensive study was conducted in August and September 1999 using 100 kHz side-scan sonar, bottom grab sampling and underwater video recording. New observations indicated that a dense population of sand dollars ( Dendraster excentricus ) coincided with the enhanced backscatter band. Compared to the two previous acoustic studies, the central section of the band expanded westward by 180 m and the southern section of the band shifted eastward by 160 m, possibly resulting from a change in the biological or physical factors which influence the location and breadth of sand dollars. The relationship between high sand dollar abundance and enhanced acoustic backscatter was further verified in the nearshore region off Samoa Beach California, where a dense, banded population of sand dollars was previously observed. Video footage confirmed the presence of a band of sand dollars, also nominally parallel to the isobaths, in water depths of 8-15 m. A band of enhanced backscatter coincided with the dense sand dollar population. The identification of dense aggregations of sand dollars through enhanced acoustic backscatter could lead to the use of acoustic techniques to study sand dollar distributions and abundance.