检索结果-南通市图书馆

Seasonal variation of mesoscale eddy intensity in the global ocean

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第1期43卷 48-58页

作者： Yongcan Zu Yue Fang Shuangwen Sun Libao Gao Yang Yang Guijun Guo First Institute of Oceanography/key laboratory of marine science and Numerical modeling Ministry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical modeling Laoshan LaboratoryQingdao 266237China Shandong key laboratory of marine science and Numerical modeling Qingdao 266061China

Mesoscale eddies are a prominent oceanic phenomenon that plays an important role in oceanic mass transport and energy *** by rotational speed,the eddy intensity is one of the most fundamental properties of an ***,the seasonal spatiotemporal variation in eddy intensity has not been examined from a global ocean *** this study,we unveil the seasonal spatiotemporal characteristics of eddy intensity in the global ocean by using the latest satellite-altimetry-derived eddy trajectory data *** results suggest that the eddy intensity has a distinct seasonal variation,reaching a peak in spring while attaining a minimum in autumn in the Northern Hemisphere and the opposite in the Southern *** seasonal variation of eddy intensity is more intense in the tropical-subtropical transition zones within latitudinal bands between 15°and 30°in the western Pacific Ocean,the northwestern Atlantic Ocean,and the eastern Indian Ocean because baroclinic instability in these areas changes *** analysis found that the seasonal variation of baroclinic instability precedes the eddy intensity by a phase of 2–3 months due to the initial perturbations needing time to grow into mesoscale eddies.

关键词： seasonal variation mesoscale eddy intensity baroclinic instability global ocean

Current observation and analysis based on mooring systems in the Andaman Sea

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第2期42卷 484-491页

作者： Yimeng WANG Jingsong GUO Dapeng QU Zhixin ZHANG Chalermrat SANGMANEE Varintha VASINAMEKHIN Binghuo GUO First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Shandong key laboratory of marine science and Numerical modeling Qingdao 266061China Phuket marine Biological Center Department of Marine and Coastal ResourcesPhuket 83000Thailand marine and Coastal Resources Research&Development Institute Department of Marine and Coastal ResourcesBangkok 10210Thailand

The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite *** observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 *** the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal *** addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency *** upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 *** analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave ***,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation *** addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.

关键词： mooring observation Wyrtki Jet Rossby waves intraseasonal variation

Evaluation of Nonbreaking Wave-Induced Mixing Parameterization Schemes Based on a One-Dimensional Ocean Model

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第3期23卷 567-576页

作者： TANG Ran HUANG Chuanjiang DAI Dejun WANG Gang The First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical modeling Laoshan LaboratoryQingdao 266237China Shandong key laboratory of marine science and Numerical modeling Qingdao 266061China

Surface waves have a considerable effect on vertical mixing in the upper *** the past two decades,the vertical mixing induced through nonbreaking surface waves has been used in ocean and climate models to improve the simulation of the upper *** far,several nonbreaking wave-induced mixing parameterization schemes have been proposed;however,no quantitative comparison has been performed among *** this paper,a one-dimensional ocean model was used to compare the performances of five schemes,including those of Qiao et al.(Q),Hu and Wang(HW),Huang and Qiao(HQ),Pleskachevsky et al.(P),and Ghantous and Babanin(GB).Similar to previous studies,all of these schemes can decrease the simulated sea surface temperature(SST),increase the subsurface temperature,and deepen the mixed layer,thereby alleviating the common thermal deviation problem of the ocean model for upper ocean *** these schemes,the HQ scheme exhibited the weakest wave-induced mixing effect,and the HW scheme exhibited the strongest effect;the other three schemes exhibited roughly the same *** particular,the Q and P schemes exhibited nearly the same *** the simulation based on observations from the Ocean Weather Station Papa,the HQ scheme exhibited the best performance,followed by the Q *** the experiment with the HQ scheme,the root-mean-square deviation of the simulated SST from the observations was 0.43℃,and the mixed layer depth(MLD)was 2.0 *** a contrast,the deviations of the SST and MLD reached 1.25℃ and 8.4 m,respectively,in the experiment without wave-induced mixing.

关键词： wave-induced mixing surface waves sea surface temperature mixed layer depth General Ocean Turbulence Model

Long-term ocean temperature trend and marine heatwaves

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第4期42卷 1037-1047页

作者： Min ZHANG Yangyan CHENG Gang WANG Qi SHU Chang ZHAO Yuanling ZHANG Fangli QIAO First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China key laboratory of marine sciences and Numerical Modelling Ministry of Natural ResourcesQingdao 266061China Shandong key laboratory of marine science and Numerical modeling Qingdao 266061China

marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and *** MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongly influences MHW *** a recent work suggesting that there should be a communicating baseline for long-term ocean temperature trends(LTT)and MHWs,we provided an effective and quantitative solution to calculate LTT and MHWs simultaneously by using the ensemble empirical mode decomposition(EEMD)*** long-term nonlinear trend of SST obtained by EEMD shows superiority over the traditional linear trend in that the data extension does not alter prior *** MHWs identified from the detrended SST data exhibited low sensitivity to the baseline choice,demonstrating the robustness of our *** also derived the total heat exposure(THE)by combining LTT and *** THE was sensitive to the fixed-period baseline choice,with a response to increasing SST that depended on the onset time of a perpetual MHW state(identified MHW days equal to the year length).Subtropical areas,the Indian Ocean,and part of the Southern Ocean were most sensitive to the long-term global warming trend.

关键词： marine heatwaves(MHWs) ensemble empirical mode decomposition(EEMD) long-term temperature(LTT)trend total heat exposure(THE)

Observation of Low-Level Jets in the Eastern Tropical Indian Ocean Based on Shipborne Coherent Doppler Lidar

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第5期23卷 1163-1172页

作者： WANG Haiyuan LIU Lin FAN Mengqi YANG Yang YANG Guang DUAN Yongliang LIU Baochao SU Qinglei ZHANG Binbin WANG Fengjun SHI Xuliang LI Qiuchi ZENG Ai First Institute of Oceanography Ministry of Natural Resources and Laboratory for Regional Oceanography and Numerical Modeling Qingdao Marine Science and Technology Center Southern marine science and Engineering Guangdong laboratory (Zhuhai) key laboratory of marine science and Numerical modeling Ministry of Natural Resources Qingdao Leice Transient Technology Co. Ltd. Qingdao Innovation and Development Base of Harbin Engineering University

In contrast to the Pacific and Atlantic Oceans, the Indian Ocean has lacked in-situ observations of wind profiles over open sea areas for decades. In 2021, a shipborne coherent Doppler lidar（CDL） was used to observe in-situ wind profiles in the eastern tropical Indian Ocean. This equipment successfully captured low-level jets（LLJs） in the region, and their characteristics were thoroughly analyzed. Results reveal that the observed wind speed of LLJs in the eastern Indian Ocean ranges from 6-1m s-1to 10 m s during the boreal winter and spring seasons, showing a height range of 0.6 to 1 km and two peak times at 0800 and 2000 UTC. This wind shear is weaker than that in land or offshore areas, ranging from 01 s-1to 0.006 s-1. Moreover, the accuracy of the CDL data is compared to that of ERA5 data in the study area. The results indicate that the zonal wind from ERA5 data significantly deviated from the CDL measurement data, and the overall ERA5 data are substantially weaker than the in-situ observations. Notably, ERA5 underestimates northwestward LLJs.

关键词： coherent Doppler lidar eastern Indian Ocean ERA5 low-level jets radiosonde

Simulated Indonesian Throughflow in Makassar Strait across the SODA3 products

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第1期43卷 80-98页

作者： Tengfei Xu Zexun Wei Haifeng Zhao Sheng Guan Shujiang Li Guanlin Wang Fei Teng Yongchui Zhang Jing Wang First Institute of Oceanography/key laboratory of marine science and Numerical modeling Ministry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical modeling Qingdao Marine Science and Technology CenterQingdao 266237China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China CAS key laboratory of Ocean Circulation and Waves Center for Ocean Mega-ScienceInstitute of OceanologyChinese Academy of ScienceQingdao 266071China

The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple Ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian Ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian Ocean to the Makassar Strait.

关键词： Indonesian Throughflow Simple Ocean Data Assimilation(SODA) El Ni?o-Southern Oscillation(ENSO) Indian Ocean Dipole(IOD) data assimilation

Long-Chain Alkenones in the South Yellow Sea Sediments and Their Indicative Significance for Haptophytes Species

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第5期23卷 1287-1296页

作者： XU Yakun YANG Xinxin XIAO Rui XING Lei key laboratory of marine Chemistry Theory and Engineering Technology Ministry of Education Ocean University of China laboratory of marine Ecology and Environment science Qingdao National Laboratory for Marine Science and Technology

Long-chain alkenones（LCAs） have been widely used as important biomarkers in palaeoceanographic ***,the commonly used LCAs proxies are mainly based on C37alkenones,and it is still lack of the studies about the distribution and indications of LCAs with different chain lengths other than ***,the composition and distribution of LCAs were analyzed in surface sediments from the southern Yellow Sea（SYS） and a sedimentary core（A02-C） from the central Yellow Sea（YS）mud *** results showed that C37,C38and C39alkenones were the major LCAs in surface sediments of the SYS,and the relative contents of C38:2Et,C37:2Me,C37:3Me,C38:2Me,C38:3Et,C38:3Me,C39:2Et and C39:3Et were 18.3%-59.8%,22.6%-41.2%,7.4%-23.0%,6.6%-15.4%,3.8%-13.3 %,3.6%-8.7%,2.8%-6.0% and 0.7%-3.0%,*** the relationships of U38MeK-U38EtKand U37K'-U38EtKindicate that LCAs are mainly derived from Emiliania huxleyi（***）.High ratios of total C37alkenones to total C38alkenones(K37/K38)（1-1.2） were found in the central SYS,corresponding to the relatively high abundance of ***;while low ratios of K37/K38（0.7-0.9） were observed at nearshore area of the SYS where Gephyrocapsa oceanica（***） has relatively high *** spatial distribution of K37/K38ratio is also consistent with that of coccolithophores nannofossil in the *** addition,K37/K38ratio in core A02-C varied from 0.7 to 1.1 with a gradual decreasing trend during the past 5.5 *** suggests that the relative abundance of *** decreased gradually,caused by the changes in the Yellow Sea Warm Current（YSWC） and the East Asian Winter Monsoon（EAWM） during this period.

关键词： alkenones sediment southern Yellow Sea Yellow Sea Warm Current

A numerical model study on the spatial and temporal variabilities of dissolved oxygen in Qinzhou Bay of the northern Beibu Gulf

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第6期43卷 49-59页

作者： Gaolei Cheng Shiqiu Peng Bin Yang Dongliang Lu State key laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China laboratory for Regional Oceanography and Numerical modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Guangxi key laboratory of marine Environmental Change and Disaster in the Beibu Gulf Beibu Gulf UniversityQinzhou 535011China

Oxygen facilitates the breakdown of the organic material to provide energy for *** concentration of dissolved oxygen(DO) in the water must exceed a certain threshold to support the normal metabolism of marine *** in the northern B eibu Gulf,Qinzhou B ay receives abundant freshwater and nutrients from several rivers which significantly influence the level of the dissolved ***,the spatial-temporal variations of DO as well as the associated driving mechanisms have been rarely studied through field *** this study,a three-dimension al coupled physical-biogeochemical model is used to investigate the spatial and seasonal variations of the DO and the associated driving mechanisms in Qinzhou B *** validation against observations indicates that the model can capture the seasonal and inter-annual variability of the DO concentration with the range of 5-10 mg/*** experiments show that the river discharges,winds and tides play crucial roles in the seasonal variability of the DO by changing the vertical mixing and stratification of the water column and the circulation *** winter,the tide and wind forces have strong effects on the DO distribution by enhancing the vertical mixing,especially near the bay *** summer,the river discharges play a dominant role in the DO distribution by inhibiting the vertical water exchange and delivering more nutrients to the Bay,which increases the DO depletion and results in lower DO on the bottom of the estuary salt *** findings can contribute to the preservation and management of the coastal environment in the northern Beibu Gulf.

关键词： river plume dissolved oxygen stratification physical-biological model

Deep learning CNN-APSO-LSSVM hybrid fusion model for feature optimization and gas-bearing prediction

在线全文

学校读者我要写书评

暂无评论

Petroleum science 2024年第4期21卷 2329-2344页

作者： Jiu-Qiang Yang Nian-Tian Lin Kai Zhang Yan Cui Chao Fu Dong Zhang College of Earth sciences and Engineering Shandong University of Science and Technology laboratory for marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Transportation Institute of Inner Mongolia University key laboratory of Gas Hydrate Qingdao Institute of Marine Geology Ministry of Natural Resources

Conventional machine learning(CML) methods have been successfully applied for gas reservoir prediction. Their prediction accuracy largely depends on the quality of the sample data; therefore, feature optimization of the input samples is particularly important. Commonly used feature optimization methods increase the interpretability of gas reservoirs; however, their steps are cumbersome, and the selected features cannot sufficiently guide CML models to mine the intrinsic features of sample data efficiently. In contrast to CML methods, deep learning(DL) methods can directly extract the important features of targets from raw data. Therefore, this study proposes a feature optimization and gas-bearing prediction method based on a hybrid fusion model that combines a convolutional neural network(CNN)and an adaptive particle swarm optimization-least squares support vector machine(APSO-LSSVM). This model adopts an end-to-end algorithm structure to directly extract features from sensitive multicomponent seismic attributes, considerably simplifying the feature optimization. A CNN was used for feature optimization to highlight sensitive gas reservoir information. APSO-LSSVM was used to fully learn the relationship between the features extracted by the CNN to obtain the prediction results. The constructed hybrid fusion model improves gas-bearing prediction accuracy through two processes of feature optimization and intelligent prediction, giving full play to the advantages of DL and CML methods. The prediction results obtained are better than those of a single CNN model or APSO-LSSVM model. In the feature optimization process of multicomponent seismic attribute data, CNN has demonstrated better gas reservoir feature extraction capabilities than commonly used attribute optimization methods. In the prediction process, the APSO-LSSVM model can learn the gas reservoir characteristics better than the LSSVM model and has a higher prediction accuracy. The constructed CNN-APSO-LSSVM mode

关键词： Multicomponent seismic data Deep learning Adaptive particle swarm optimization Convolutional neural network Least squares support vector machine Feature optimization Gas-bearing distribution prediction