Marine Geodesy最新文献_第9页

Sub-Surface Ocean Structure from Satellite Surface Observations in the North Indian Ocean 北印度洋卫星地面观测的次表层海洋结构

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-09-11 DOI: 10.1080/01490419.2021.1974132

A. Mandal, Aditya Chaudhary, N. Agarwal, Rashmi Sharma

{"title":"Sub-Surface Ocean Structure from Satellite Surface Observations in the North Indian Ocean","authors":"A. Mandal, Aditya Chaudhary, N. Agarwal, Rashmi Sharma","doi":"10.1080/01490419.2021.1974132","DOIUrl":"https://doi.org/10.1080/01490419.2021.1974132","url":null,"abstract":"Abstract In this study interior plus Surface Quasi-Geostrophic (isQG) methodology is used to reconstruct subsurface density anomaly using sea surface temperature (SST), sea surface salinity (SSS) and sea surface height (SSH). The study is carried out in the Arabian Sea and Bay of Bengal of the Northern Indian ocean region. isQG is first tested for identical twin experiments, where the surface data and the stability profile (N2) were taken from a numerical ocean model. The root mean square error (RMSE) between isQG and model density anomalies lie within the error bars of model density anomaly in most of the levels. The impact of expected errors in synthetic observations of SST and SSS on isQG retrieved density anomalies was studied and it is found that error in SSS results in greater RMSE in isQG density anomaly profile in the Arabian sea than in the Bay of Bengal. isQG method is then applied to the satellite observations of SST, SSS and SSH and retrieved density profiles are then compared with model outputs and in-situ observations from RAMA buoy for the year 2019. The comparison indicates seasonal dependency and effect of N2 on the performance of isQG method.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43475134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

GIS-Based Study on the Environmental Sensitivity to Pollution and Susceptibility to Eutrophication in Burullus Lake, Egypt 基于gis的埃及布鲁勒斯湖环境污染敏感性及富营养化敏感性研究

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-07-27 DOI: 10.1080/01490419.2021.1954111

M. El-Alfy, Dina H. Darwish, Afifi I. Basiony, A. Elnaggar

{"title":"GIS-Based Study on the Environmental Sensitivity to Pollution and Susceptibility to Eutrophication in Burullus Lake, Egypt","authors":"M. El-Alfy, Dina H. Darwish, Afifi I. Basiony, A. Elnaggar","doi":"10.1080/01490419.2021.1954111","DOIUrl":"https://doi.org/10.1080/01490419.2021.1954111","url":null,"abstract":"Abstract Sensitivity to pollution in Burullus Lake was estimated based on the proximity analysis. The category of sensitivity was based on six factors including: agricultural areas, industrial areas, drains, Elboughaz, urban areas and fish farms. A statistical model was developed to estimate trophic state index (TSI) based on laboratory measurements of water samples at two different periods of time (Mach 2020 and June 2020) (R2 = 0.96 and 0.94, respectively). The important factors that were considered at the first period were chlorophyll, phosphate PO4 and oxidizable organic matter OOM. In the second period, the considered factors were ammonia NH4, silicates SiO4, and dissolved oxygen (DO). The category of TSI varied from oligotrophic to hyper-eutrophic conditions in March 2020, whereas it varied from eutrophic to hyper-eutrophic in June 2020. The eutrophication condition was higher in June than in March. This may be attributed to the huge amount of wastewaters, their contaminant load and season. The compatibility between sensitivity model and the obtained results in March 2020 was about 54.5%, whereas it was about 27.3% in June 2020. This reveals that the lake is highly sensitive to pollution and therefore it needs to be monitored regularly.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1954111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41760911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Bathymetry Model in the Northwestern Pacific Ocean Predicted from Satellite Altimetric Vertical Gravity Gradient Anomalies and Ship-Board Depths 利用卫星测高垂直重力梯度异常和船载深度预测西北太平洋测深模式

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-06-24 DOI: 10.1080/01490419.2021.1943576

Minzhang Hu, T. Jin, Weiping Jiang, Yonghai Chu, Hanjiang Wen, Jiancheng Li

{"title":"Bathymetry Model in the Northwestern Pacific Ocean Predicted from Satellite Altimetric Vertical Gravity Gradient Anomalies and Ship-Board Depths","authors":"Minzhang Hu, T. Jin, Weiping Jiang, Yonghai Chu, Hanjiang Wen, Jiancheng Li","doi":"10.1080/01490419.2021.1943576","DOIUrl":"https://doi.org/10.1080/01490419.2021.1943576","url":null,"abstract":"Abstract New bathymetry models in the northwestern Pacific Ocean are presented at 1 arc-minute and 15 arc-second resolution. The latest version of the altimetric vertical gravity gradient (VGG) anomalies from Scripps Institute of Oceanography, ∼7 million single-beam depths from the National Centers for Environmental Information, and ∼80 GB of multibeam grids from the Japan Agency for Marine-Earth Science and Technology are used. The ship-board depths are used to constrain bathymetry at wavelengths longer than 200 km, and calibrate the local topography to VGG ratio at 15–200 km wavelength bands. The VGG is used to predict bathymetry at 15 ∼ 200 km wavelength bands. The spectrum analysis results show that the 1 arc-minute model has more power than models predicted from gravity anomalies at wavelengths shorter than 100 km. The standard deviation of differences between the 1 arc-minute model and ship-board depths is 44.76 m, and it is 102.842 m comparing to the SIO topo_20.1.nc model. The accuracy of the new 1 arc-minute model has been improved significantly from our last bathymetry model, BAT_VGG, and has a better accuracy than that of the DTU18, GEBCO_08, and ETOPO1 models. The accuracy of the 15 arc-second model is consistent with that of SRTM + V2.1 and GEBCO_2020.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1943576","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43223102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Providing a Levelling Datum to a Tide Gauge Sea Level Record 为潮汐计海平面记录提供水准基准面

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-06-15 DOI: 10.1080/01490419.2021.1943577

P. Woodworth

引用次数: 0

Remote Sensing Method for Extracting Topographic Information on Tidal Flats Using Spatial Distribution Features 利用空间分布特征提取滩涂地形信息的遥感方法

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-06-04 DOI: 10.1080/01490419.2021.1925791

Y. Lijun, Xiao Yao, Jiang Jie, Yixiang Chen, Gu Yan, Sentong Zhang

{"title":"Remote Sensing Method for Extracting Topographic Information on Tidal Flats Using Spatial Distribution Features","authors":"Y. Lijun, Xiao Yao, Jiang Jie, Yixiang Chen, Gu Yan, Sentong Zhang","doi":"10.1080/01490419.2021.1925791","DOIUrl":"https://doi.org/10.1080/01490419.2021.1925791","url":null,"abstract":"Abstract A remote sensing method combining remote sensing and ground surveying is proposed to extract tidal flat topographic information via the spatial distribution characteristics of tidal flat surface features. Based on the eastern Chongming beach of the Yangtze Estuary and Landsat-5 satellite images, this study identifies the spatial distribution characteristics of tidal flat features using field-based RTK data and spectral data. The remote sensing method for extracting the geometric and physical characteristics of linear and surface geographical elements on tidal flats and the elevation assignment method are discussed. The effectiveness of this method is verified by the quality of the resultant tidal flat DEM. The results show that the use of spatial distribution features in remote sensing images can provide rich topographic information. The DEM results have an accuracy of 0.16 m, are in line with the basic topographic patterns of tidal flats, and can describe local microscale geomorphic features. This technique solves the problem of a single topographic information source in current remote sensing measurement methods and provides technical support for detecting dynamic changes in coastal zones by using remote sensing technology.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1925791","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43085071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Grain Size Analysis and Characterization of Sedimentary Process in Tidal Flat of Chandipur Region, East Coast of India 印度东海岸昌迪普尔地区潮滩沉积过程的粒度分析与表征

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-06-01 DOI: 10.1080/01490419.2021.1922554

K. Saha, Subhajit Sinha

{"title":"Grain Size Analysis and Characterization of Sedimentary Process in Tidal Flat of Chandipur Region, East Coast of India","authors":"K. Saha, Subhajit Sinha","doi":"10.1080/01490419.2021.1922554","DOIUrl":"https://doi.org/10.1080/01490419.2021.1922554","url":null,"abstract":"Abstract Sediment characteristics and distribution analysis along the Chandipur Coast in Odisha, India was performed using a variety of techniques that include sedimentary characteristics including variation in grain size, shape and character of quartz grain surfaces (determined in light microscope and electron microscope scanning). Samples were taken from various locations representing high-tide areas and low-tide areas for analysis of the grain size, intended to determine physical properties and textural parameters such as mean, sorting, skewness and kurtosis. Grain size distribution research was conducted to characterize sedimentary transportation behaviours. CM diagram defines the rolling, saltation and graded suspension process for sediment deposition at the beach. Linear Discriminant Function (LDF) indicates the superiority of marine environment with lower deposition areas. Scanning Electron Microscope (SEM) was used to examine the quartz grains to determine the origin of the sediments and to establish the physical and chemical processes that occurred during their period of deposition in recent coastal sediments.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1922554","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41908112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Monitoring Sea Surface Currents Based on China GF-4 Multispectral Data 基于中国GF-4多光谱资料的海面海流监测

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-05-24 DOI: 10.1080/01490419.2021.1925788

Hequan Sun, Zeyu Li, Ruoli Shao

引用次数: 0

Special Issue of Marine Geodesy on Seafloor Geodesy and Acoustic Positioning 海洋大地测量学海底大地测量与声学定位特刊

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-05-06 DOI: 10.1080/01490419.2021.1911038

Rongxing Li

引用次数: 0

Extracting Shallow-Water Bathymetry from Lidar Point Clouds Using Pulse Attribute Data: Merging Density-Based and Machine Learning Approaches 利用脉冲属性数据从激光雷达点云提取浅水测深:融合基于密度的方法和机器学习方法

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-05-05 DOI: 10.1080/01490419.2021.1925790

K. Lowell, B. Calder

{"title":"Extracting Shallow-Water Bathymetry from Lidar Point Clouds Using Pulse Attribute Data: Merging Density-Based and Machine Learning Approaches","authors":"K. Lowell, B. Calder","doi":"10.1080/01490419.2021.1925790","DOIUrl":"https://doi.org/10.1080/01490419.2021.1925790","url":null,"abstract":"Abstract To automate extraction of bathymetric soundings from lidar point clouds, two machine learning (ML 1 ) techniques were combined with a more conventional density-based algorithm. The study area was four data “tiles” near the Florida Keys. The density-based algorithm determined the most likely depth (MLD) for a grid of “estimation nodes” (ENs). Unsupervised k-means clustering determined which EN’s MLD depth and associated soundings represented ocean depth rather than ocean surface or noise to produce a preliminary classification. An extreme gradient boosting (XGB) model was fitted to pulse return metadata – e.g. return intensity, incidence angle – to produce a final Bathy/NotBathy classification. Compared to an operationally produced reference classification, the XGB model increased global accuracy and decreased the false negative rate (FNR) – i.e. undetected bathymetry – that are most important for nautical navigation for all but one tile. Agreement between the final XGB and operational reference classifications ranged from 0.84 to 0.999. Imbalance between Bathy and NotBathy was addressed using a probability decision threshold that equalizes the FNR and the true positive rate (TPR). Two methods are presented for visually evaluating differences between the two classifications spatially and in feature-space.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1925790","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45108089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Evaluating the Suitability of Multi-Scale Terrain Attribute Calculation Approaches for Seabed Mapping Applications 多尺度地形属性计算方法在海底测绘中的适用性评价

IF 1.6 4区地球科学

Marine Geodesy Pub Date : 2021-05-05 DOI: 10.1080/01490419.2021.1925789

B. Misiuk, V. Lecours, M. Dolan, K. Robert

{"title":"Evaluating the Suitability of Multi-Scale Terrain Attribute Calculation Approaches for Seabed Mapping Applications","authors":"B. Misiuk, V. Lecours, M. Dolan, K. Robert","doi":"10.1080/01490419.2021.1925789","DOIUrl":"https://doi.org/10.1080/01490419.2021.1925789","url":null,"abstract":"Abstract The scale dependence of benthic terrain attributes is well-accepted, and multi-scale methods are increasingly applied for benthic habitat mapping. There are, however, multiple ways to calculate terrain attributes at multiple scales, and the suitability of these approaches depends on the purpose of the analysis and data characteristics. There are currently few guidelines establishing the appropriateness of multi-scale raster calculation approaches for specific benthic habitat mapping applications. First, we identify three common purposes for calculating terrain attributes at multiple scales for benthic habitat mapping: (i) characterizing scale-specific terrain features, (ii) reducing data artefacts and errors, and (iii) reducing the mischaracterization of ground-truth data due to inaccurate sample positioning. We then define criteria that calculation approaches should fulfill to address these purposes. At two study sites, five raster terrain attributes, including measures of orientation, relative position, terrain variability, slope, and rugosity were calculated at multiple scales using four approaches to compare the suitability of the approaches for these three purposes. Results suggested that specific calculation approaches were better suited to certain tasks. A transferable parameter, termed the ‘analysis distance’, was necessary to compare attributes calculated using different approaches, and we emphasize the utility of such a parameter for facilitating the generalized comparison of terrain attributes across methods, sites, and scales.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/01490419.2021.1925789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41501594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12