Comparison and Combination of Coastal and Off-Shore Tide Gauge Measurements from Eivissa Island,Western Mediterranean     

Andreas Richter  Marta Marcos  Sebastià Monserrat  Damià Gomis  Simon Ruiz  Gunter Liebsch 《Marine Geodesy》2013,36(4):271-289

Two sea-level records, spanning eight months of simultaneous data in 2002, have been derived from pressure tide gauge measurements at Sant Antoni harbor (Eivissa Island, Western Mediterranean) and off Es Vedrà island, 15 km SW from Sant Antoni. The two time series are compared and used to characterize the sea-level variability in the Balearic Sea. The main forcings for the observed variations, astronomic tides, and meteorologic forcing by the inverse barometer effect are quantified. In a further step, an amplitude transfer function is determined, reflecting the frequency dependent amplification or damping of the nontidal sea-level residuals between both locations due to their local topography. The interpretation of the obtained transfer function indicates sea-level modulating topographic specifics not only for the coastal record at Sant Antoni, but also at the Es Vedrà site. In general, the application of such a transfer function allows the prediction of off-shore sea-level variations from coastal tide gauge measurements. In the present study, ellipsoidal sea-surface heights for Es Vedrà are inferred from Sant Antoni tide gauge data with an accuracy of about 1.5 cm by applying the determined transfer function and a geoid model.  相似文献   

Editorial     

Karl Rinner 《Marine Geodesy》2013,36(3):203-205

The long‐term mean sea level in the Baltic Sea is investigated using the coupled three‐basin model constructed by Carlsson (1997). The model is forced by the observed sea level in the Kattegat, the freshwater supply, horizontal air pressure and density gradients, and the wind stress. Both the seasonal variations and the slope of the mean sea level are investigated and compared with the results of another oceanographic model (Lisitzin, 1962) and a geodetic model (Ekman &; Mäkinen, 1996). In the geodetic model an unofficial height system, NH60, is used, and one part of the investigation is to find out whether this height system is useful for oceanographers. The estimated mean sea level difference between the northern and the southern parts of the Baltic Sea are: 17.1 cm (the present model), 26 cm (Lisitzin's model), and 18.3 cm (the geodetic model). It is concluded that the mean sea level difference between the northern and southern parts of the Baltic Sea is due mainly to horizontal variations of density and air pressure, and that the height system NH60 is suitable for oceanographie applications.  相似文献   

南黄海浮游动物主要种类数量分布年间比较   总被引：3，自引：0，他引：3  

陈峻峰  左涛  王秀霞 《海洋学报》2013,35(6):195-203

分析对比1959年、1982年、1998-2000年以及2007-2010年4个不同时期南黄海中部（34.25°~37.45°N,122.00°~124.00°E）浮游动物主要优势种中华哲水蚤（Calanus sinicus）、太平洋磷虾（Euphausia pacifica）和强壮箭虫（Sagitta crassa）数量时空变化及其与温度、盐度和太平洋年代际震荡指数（Pacific Decadal Oscillation,PDO）变动的关系。结果显示,温度可能对中华哲水蚤和太平洋磷虾数量分布影响较大;强壮箭虫则受盐度影响较大。PDO暖位相时期中华哲水蚤和太平洋磷虾数量显著低于冷位相时期,强壮箭虫则相反。中华哲水蚤和太平洋磷虾丰度与提前3个月PDO值呈显著正相关,强壮箭虫丰度仅与当月PDO值呈显著正相关。  相似文献   

Seasonal and gender-related differences in morphometric features and cellular and biochemical parameters of Carcinus aestuarii from the Lagoon of Venice     

《Marine environmental research》2013

In this study, the seasonal variations in the morphometric features and in the cellular and biochemical parameters of the haemolymph were investigated in both male and female crabs (Carcinus aestuarii). Crabs were seasonally (November 2010–August 2011) collected from the Lagoon of Venice, and the moult stage, weight, width and length of the carapace, and width and length of the bigger chela were evaluated. In addition, the total haemocyte count (THC), haemocyte diameter and volume, haemolymph glucose and total protein levels, and haemolymph phenoloxidase (PO) and N-acetyl-β-glucosaminidase (NAG) activities were measured. The results demonstrated that the collected crabs were all in the intermoult stage and that the males were bigger than the females. A two-way ANOVA revealed a significant effect of season on the THC and the haemocyte volume and a significant influence of gender on the haemocyte diameter. Season and gender significantly affected the haemolymph glucose concentration, whereas haemolymph protein levels were dependent only on the season. In addition, both season and gender significantly influenced the PO and NAG activities in the haemolymph. Overall, the results demonstrated that crab morphometric features as well as haemolymph cellular and biochemical parameters varied markedly as a function of both season and gender.  相似文献   

Nematode diversity in different microhabitats in a mangrove region     

Taciana K. Pinto  Melanie C. V. Austen  Richard M. Warwick  Paul J. Somerfield  André M. Esteves  Francisco J. V. Castro  Verônica G. Fonseca‐Genevois  Paulo J. P. Santos 《Marine Ecology》2013,34(3):257-268

Mangroves are highly productive environments that play important ecological and socioeconomic roles; however, they have been impacted to different degrees in most countries worldwide. The knowledge of which organisms inhabit this environment and their ecological interactions is the first step towards its conservation. The natural variability of environmental factors in mangroves provides numerous niches available to different species. Meiofauna have patchy patterns of distribution that are related to the availability of resources. Hence, meiofauna are expected to present a high diversity of different taxa occupying the different microhabitats offered by mangroves. This work aims to test the hypothesis that the assemblage structure of Nematoda varies significantly among mangrove microhabitats and to contribute knowledge on the meiofauna diversity in mangrove environments. This work was carried out in a mangrove region at Pernambuco state, Northeastern Brazil. Qualitative samples were collected in nine microhabitats which show different characteristics mainly in terms of presence of vegetation or another organism and sediment grain size. Univariate and multivariate analysis were applied to Nematoda genera abundance data. Our results demonstrate the existence of significant differences among microhabitats regarding nematode assemblage structure corroborating the hypothesis. Different Nematoda assemblages are present in at least seven microhabitats. These assemblages are composed of nematode genera with different trophic and morphological features, demonstrating a strong relationship between morphological diversity and ecological plasticity. Furthermore, this study also demonstrates the importance of the conservation of this ecosystem and its attributes.  相似文献   

Interannual variations of the air-sea carbon dioxide exchange in the different regions of the Pacific Ocean     

LI Yangchun  XU Yongfu 《海洋学报(英文版)》2013,32(3):71-79

Interannual variations of the air-sea CO 2 exchange from 1965 to 2000 in the Pacific Ocean are studied with a Pacific Ocean model.Two numerical experiments are performed,including the control run that is forced by climatological monthly mean physical data and the climate-change run that is forced by interannually varying monthly mean physical data.Climatological monthly winds are used in both runs to calculate the coefficient of air-sea CO 2 exchange.The analysis through the differences between the two runs shows that in the tropical Pacific the variation of export production induced by interannual variations of the physical fields is negatively correlated with that of the air-sea CO 2 flux,while there is no correlation or a weak positive correlation in the subtropical North and South Pacific.It indicates that the variation of the physical fields can modulate the variation of the air-sea CO 2 flux in converse ways in the tropical Pacific by changing the direct transport and biochemical process.Under the interannually varying monthly mean forcing,the simulated EOF1 of the air-sea CO 2 flux is basically consistent with that of sea surface temperature(SST) in the tropical Pacific,but contrary in the two subtropical Pacific Ocean.The correlation coefficient between the regionally integrated air-sea CO 2 flux and area-mean SST shows that when the air-sea CO 2 flux lags SST by about 5 months,the positive coefficient in the three regions is largest,indicating that in the tropical Pacific or on the longer time scale in the three regions,physical processes control the flux-SST relationship.  相似文献   

Morphological Features of Co-Rich Manganese Deposits and Their Relation to Seabed Slopes     

Tetsuo Yamazaki  Rahul Sharma 《Marine Georesources & Geotechnology》2013,31(1):43-76

Abstract

The morphological features associated with Co-rich manganese deposits, the size variations of nodules, and the occurrence of different substrates have been analyzed, to evaluate the influence of various seabed slope angles on the distribution of these features. The coverage and size of the crusts depend on their surface morphology and seabed topography, resulting in cobble-type, lineated, or step-like outcrops. Small nodules (1–4 cm in diameter) dominate all seabed slopes, with a few locations having nodules ranging from 1 to 8 or 1 to 10 cm. Sediments invariably occur as substrates for nodules and as cover for crusts, their coverage being inversely proportional to that of the nodules and crust outcrops.

Steeper seafloor areas have large crust outcrops exposed with no or few nodules and sediments associated with them. The intermediate slopes have a combination of nodules, sediments, and crusts in various proportions, depending on topography and gradient. Large-scale nodule occurrences, followed by sediment fields and crust outcrops on seabed slopes of < 3°, 3–7°, and > 15°, respectively, represent typical morphological distribution zones of the Co-rich manganese deposits on a seamount in the central Pacific Ocean. A transition zone between nodule-dominated fields and large crust outcrops occurs for slopes from 7° to 15°. This detailed study on distribution of Co-rich deposits gives a better understanding for purposes of their exploitation.  相似文献   

华北冬季气温年代际变化及大气环流分析   总被引：6，自引：4，他引：2  

申红艳  丁裕国  张捷 《气象科学》2010,30(3):338-343

用NCEP/NCAR再分析资料和华北地区冬季气温资料,运用经验正交分解(EOF)和合成分析等方法,分析了华北地区冬季气温年代际异常及同期环流背景场的变化特征。结果表明:华北冬季气温的年代际变化特征明显;北半球冬季环流场的年代际变化是造成华北冬季气温年代际异常的根本原因,在近地面层,西伯利亚高压偏强时,华北冬季偏冷,反之亦然;在对流层中层,东亚大槽及贝加尔湖高压脊为主要影响系统;低空风场分析结果显示,华北冬季偏冷期中、高纬纬向环流减弱,经向环流明显增强,主要盛行偏北风,暖期情况正好相反。另据分析,北极涛动的年代际变化与华北冬季气温异常也有很好的相关性。  相似文献   

我国东部地区夏季不同等级降水日数年际变化特征分析   总被引：7，自引：3，他引：4  

艾卉  张耀存  卢伟 《气象科学》2009,29(3)

用全国1958--2004年逐日降水资料,分析我国东部地区夏季总降水日数以及不同等级降水日数的年代际变化特征,结果表明,1980--2004年与1958--1979年两个时段相比,我国东部各地区夏季总降水日数和不同等级降水日数具有明显不同的变化特征。东北地区总降水日数和总降水量减少,这主要与小雨日数减少有关。华北地区总雨日数和总降水量也呈减少特征,总雨日数减少是由于各等级雨日数减少引起,且小雨日数减少贡献较大,而总降水量减少却主要是由于暴雨日数的减少引起。长江流域总降水日数和总降水量增加,总雨日数增多主要与中雨以上级别雨日数的增多有关,而总降水量的增加主要与暴雨日数增加有关。华南地区总雨日数和总降水量减少,总雨日数减少主要与小雨日数减少有关,而总降水量减少是由于各等级降水日数减少引起。  相似文献   

广东省年蒸发量的时空演变特征     

范伶俐  郭品文  张福颖  吴德平  缪集群 《南京气象学院学报》2010,33(3):321-327

利用广东省86个气象站点1961—2003年的地面气象观测数据,采用经验正交函数分解（EOF）和相关分析法,分析了广东省年蒸发皿蒸发量和实际蒸发量的时空变化。结果表明,粤东沿海、珠三角和粤西南等沿海地区是广东省年蒸发皿蒸发量的主要气候变异中心,广东省沿海年蒸发皿蒸发量具有以年代际变化为主的特征,并且在43 a内总体上呈下降趋势,广东省沿海地区与粤东、粤中地区年蒸发皿蒸发量气候变化趋势的差异,可能是由于饱和差、近地面风速在两个区域的气候变化变幅不同所致。在影响蒸发皿蒸发量的因子中,太阳辐射与蒸发皿蒸发量的相关性最好,呈显著的正相关。对实际蒸发量而言,在全省范围内均表现为以年际变化为主的特征,太阳辐射对广东省年实际蒸发量的影响最为显著,广东省年实际蒸发量一般都占蒸发皿蒸发量的50%左右,并且比值总体上呈现微弱的由沿海地区向粤东、粤中地区递增的趋势。研究结果可为今后探讨广东省水资源异常和旱涝气候灾害的成因提供依据。  相似文献