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Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River

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Journal of Ocean University of china 2024年第1期23卷 99-108页

作者： ZHANG Han BURNETT CWilliam ZHANG Xiaojie ZHAO Shibin YANG Disong NAN Haiming YU Zhigang XU Bochao Frontiers Science center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of EducationOcean University of ChinaQingdao 266100China Laboratory for marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahasseeFL 32306USA north china sea Environmental Monitoring center State Oceanic AdministrationKey Laboratory of Ecological Prewarning and Protection of Bohai SeaMNRQingdao 266033China Shandong Provincial Key Laboratory of marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266033China

Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.

关键词： the Yellow River suspended particulate matter size-fractions radionuclides sediment sources water elutriator

Impacts of Water-Sediment Regulation Scheme on Chromophoric Dissolved Organic Matter in the Lower Yellow River

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Journal of Ocean University of china 2024年第2期23卷 455-466页

作者： LIU Xiao JIANG Xueyan LIU Qian SUI Juanjuan ZOU Li Key Laboratory of marine Chemistry Theory and Technology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China School of Earth Sciences University of BristolBristolBS81RJUK north china sea Environmental Monitoring center State Oceanic AdministrationQingdao 266033China Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai SeaMinistry of Natural ResourcesQingdao 266033China Key Laboratory of marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China

As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water quality.Water-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water quality.Chromophoric dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human activities.Here,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during WSRS.In addition,a parallel factor fluorescence analysis(PARAFAC)method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3)and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3 increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM compositions.Under the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS period.Sediment resuspension inhibits microbial activities and reduces the production of autochthonous CDOM.Overall,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment.

关键词： chromophoric dissolved organic matter(CDOM) water-sediment regulation scheme(WSRS) Yellow River optical properties

Panoptic UAV:Panoptic Segmentation of UAV Images for marine Environment Monitoring

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工程与科学中的计算机建模(英文) 2024年第1期138卷 1001-1014页

作者： Yuling Dou Fengqin Yao Xiandong Wang Liang Qu Long Chen Zhiwei Xu Laihui Ding Leon Bevan Bullock Guoqiang Zhong Shengke Wang School of Computer Science and Technology Ocean University of ChinaQingdao266100China north china sea Environmental Monitoring center State Oceanic AdministrationQingdao266000China Department of Informatics University of LeicesterLeicesterLE17RHUK Research and Development Department Shandong Willand Intelligent Technology Co.Ltd.Qingdao266102China

UAV marine monitoring plays an essential role in marine environmental protection because of its flexibility and convenience,low cost and convenient maintenance.In marine environmental monitoring,the similarity between objects such as oil spill and sea surface,Spartina alterniflora and algae is high,and the effect of the general segmentation algorithm is poor,which brings new challenges to the segmentation of UAV marine images.Panoramic segmentation can do object detection and semantic segmentation at the same time,which can well solve the polymorphism problem of objects in UAV ocean images.Currently,there are few studies on UAV marine image recognition with panoptic segmentation.In addition,there are no publicly available panoptic segmentation datasets for UAV images.In this work,we collect and annotate UAV images to form a panoptic segmentation UAV dataset named UAV-OUC-SEG and propose a panoptic segmentation method named PanopticUAV.First,to deal with the large intraclass variability in scale,deformable convolution and CBAM attention mechanism are employed in the backbone to obtain more accurate features.Second,due to the complexity and diversity of marine images,boundary masks by the Laplacian operator equation from the ground truth are merged into feature maps to improve boundary segmentation precision.Experiments demonstrate the advantages of PanopticUAV beyond the most other advanced approaches on the UAV-OUC-SEG dataset.

关键词： Panoptic segmentation UAV marine monitoring attention mechanism boundary mask enhancement

New Record Ocean Temperatures and Related Climate Indicators in 2023

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Advances in Atmospheric Sciences 2024年第6期41卷 1068-1082页

作者： Lijing CHENG John ABRAHAM Kevin E.TRENBERTH Tim BOYER Michael EMANN Jiang ZHU Fan WANG Fujiang YU Ricardo LOCARNINI John FASULLO Fei ZHENG Yuanlong LI Bin ZHANG Liying WAN Xingrong CHEN Dakui WANG Licheng FENG Xiangzhou SONG Yulong LIU Franco RESEGHETTI Simona SIMONCELLI Viktor GOURETSKI Gengxin CHEN Alexey MISHONOV Jim REAGAN Karina VON SCHUCKMANN Yuying PAN Zhetao TAN Yujing ZHU Wangxu WEI Guancheng LI Qiuping REN Lijuan CAO Yayang LU International center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of St.Thomas School of EngineeringMinnesota 55105USA NSF National center for Atmospheric Research BoulderColorado 80307USA University of Auckland Auckland 1010New Zealand National oceanic and Atmospheric administration National Centers for Environmental InformationSilver SpringMaryland 20910USA Department of Earth and Environmental Science University of PennsylvaniaPhiladelphiaPennsylvania 19104USA Institute of Oceanology Chinese Academy of SciencesQingdao 266071China National marine Environmental forecasting center Ministry of Natural Resources of ChinaBeijing 100081China Oceanographic Data center Chinese Academy of SciencesQingdao 266071China College of Oceanography Hohai UniversityNanjing 210098China National marine Data and Information Service Tianjin 300171China Italian National Agency for New Technologies Energy and Sustainable Economic DevelopmentS.Teresa Research CenterLerici 19032Italy Istituto Nazionale di Geofisica e Vulcanologia Sede di BolognaBologna 40128Italy South china sea Institute of Oceanology Chinese Academy of SciencesGuangzhou 510301China ESSIC/CISESS-MD University of MarylandCollege ParkMD20740USA Mercator Ocean International Toulouse 31400France Eco-Environmental Monitoring and Research center Pearl River Valley and South China Sea Ecology and Environment AdministrationMinistry of Ecology and EnvironmentPRCGuangzhou 510611China National Meteorological Information center China Meteorological AdministrationBeijing 100081China International Research center of Big Data for Sustainable Development Goals Beijing 100094China

The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record highs.The 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean sea,and southern oceans recorded their highest OHC observed since the 1950s.Associated with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of 2023.The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.

关键词： ocean heat content salinity stratification global warming climate

Effect of the Initial Vortex Structure on Intensity Change During Eyewall Replacement Cycle of Tropical Cyclones:A Numerical Study

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Journal of Tropical Meteorology 2024年第2期30卷 106-117页

作者：杨昕玮王玉清王慧徐晶占瑞芬 state Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 China University of Chinese Academy of Sciences Beijing 101408 China Department of Atmospheric Sciences and International Pacific Research center School of Earth and Ocean Science and TechnologyUniversity of Hawaii at ManoaHonoluluHI 96822 USA Qingdao Joint Institute of marine Meteorology Chinese Academy of Meteorological SciencesChina Meteorological AdministrationQingdaoShandong 266034 China Department of Atmospheric and oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200438 China

This study investigates the effect of the initial tropical cyclone(TC)vortex structure on the intensity change during the eyewall replacement cycle(ERC)of TCs based on two idealized simulations using the Weather Research and forecasting(WRF)model.Results show that an initially smaller TC with weaker outer winds experienced a much more drastic intensity change during the ERC than an initially larger TC with stronger outer winds.It is found that an initially larger TC vortex with stronger outer winds favored the development of more active spiral rainbands outside the outer eyewall,which slowed down the contraction and intensification of the outer eyewall and thus prolonged the duration of the concentric eyewall and slow intensity evolution.In contrast,the initially smaller TC with weaker outer winds corresponded to higher inertial stability in the inner core and weaker inertial stability but stronger filamentation outside the outer eyewall.These led to stronger boundary layer inflow,stronger updraft and convection in the outer eyewall,and suppressed convective activity outside the outer eyewall.These resulted in the rapid weakening during the formation of the outer eyewall,followed by a rapid re-intensification of the TC during the ERC.Our study demonstrates that accurate initialization of the TC structure in numerical models is crucial for predicting changes in TC intensity during the ERC.Additionally,monitoring the activity of spiral rainbands outside the outer eyewall can help to improve short-term intensity forecasts for TCs experiencing ERCs.

关键词： tropical cyclones concentric eyewall inner eyewall and outer eyewall eyewall replacement cycle intensity change

New perspectives on deep carbon cycling

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Science china Earth Sciences 2024年第8期67卷 2411-2422页

作者： Weidong SUN center of Deep sea Research Key Laboratory of Ocean Observation and Forecasting Institute of Oceanology Chinese Academy of Sciences Laoshan Laboratory University of Chinese Academy of Sciences

The proto-atmosphere serves as a crucial starting point for the carbon cycle. Estimations based on atmospheric data from Mars and Venus suggest that Earth's proto-atmosphere contained >110 bar of CO2and >2.6 bar of nitrogen. The protoatmosphere had over 1000 bar of water vapor during the magma ocean stage, assuming the proto-ocean had a volume of two oceans of water. During this stage both water and carbon dioxide were in a supercritical state at the magma-atmosphere interface.Intense serpentinization reactions occurred due to rock-water interaction, producing abundant hydrogen. Consequently, nitrogen is reduced to ammonia, and carbon dioxide to methane, forming carbonate simultaneously. The proto-atmosphere dominated by methane, ammonia, and hydrogen formed a significant amount of amino acids through lightning. This process is essential not only to the origin of life, but also to the early carbon-nitrogen cycle on Earth. By the Hadean eon, a large amount of CO2was sequestered as carbonate and organic material. Subsequently, it mainly entered the deep mantle through mantle overturn or subduction. In the mantle transition zone, carbonate undergoes “Redox freezing”, where carbonate is reduced to diamond through oxidation of ferrous iron in the melt. In the lower mantle, Fe2+undergoes disproportionation reactions, forming Fe3+and metallic iron. Among these, Fe3+mainly resides in bridgmanite, thereby increasing the oxygen fugacity of the lower mantle,while metallic iron falls to the Earth's core. The distribution of carbon in the mantle is crucial for deep carbon cycling. The density curves of diamond and mantle peridotite melt intersect at the bottom of the mantle transition zone（about 660 km）. This density crossover leads to the accumulation of diamond during the magma ocean stage. When materials such as subducting slabs enter the lower mantle, compensatory upwelling of lower mantle material occurs. Bridgmanite enters the upper mantle, decomposes, releasing Fe3+ions and oxidizes diamond to carbonate, which under th

关键词： Carbon cycling Proto-atmosphere Amino acids Subduction initiation Passive margin subduction Atmospheric carbon dioxide

A Spatiotemporal Interactive Processing Bias Correction Method for Operational Ocean Wave Forecasts

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Journal of Ocean University of china 2022年第2期21卷 277-290页

作者： AI Bo YU Mengchao GUO Jingtian ZHANG Wei JIANG Tao LIU Aichao WEN Lianjie LI Wenbo College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China north china sea marine forecasting center of state oceanic administration Qingdao 266100China 391033 Troops People’s Liberation Army of ChinaQingdao 266000China

Numerical models and correct predictions are important for marine forecasting,but the forecasting results are often unable to satisfy the requirements of operational wave forecasting.Because bias between the predictions of numerical models and the actual sea state has been observed,predictions can only be released after correction by forecasters.This paper proposes a spati-otemporal interactive processing bias correction method to correct numerical prediction fields applied to the production and release of operational ocean wave forecasting products.The proposed method combines the advantages of numerical models and Forecast Discussion;specifically,it integrates subjective and objective information to achieve interactive spatiotemporal correc-tions for numerical prediction.The method corrects the single-time numerical prediction field in space by spatial interpolation and sub-zone numerical analyses using numerical model grid data in combination with real-time observations and the artificial judg-ment of forecasters to achieve numerical prediction accuracy.The difference between the original numerical prediction field and the spatial correction field is interpolated to an adjacent time series by successive correction analysis,thereby achieving highly efficient correction for multi-time forecasting fields.In this paper,the significant wave height forecasts from the European Centre for Medium-Range Weather Forecasts are used as background field for forecasting correction and analysis.Results indicate that the proposed method has good application potential for the bias correction of numerical predictions under different sea states.The method takes into account spatial correlations for the numerical prediction field and the time series development of the numerical model to correct numerical predictions efficiently.

关键词： numerical models ocean wave forecasts spatial interpolation time series interpolation successive correction

Long-term trend analysis of wave characteristics in the Bohai sea based on interpolated ERA5 wave reanalysis from 1950 to 2020

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Acta Oceanologica Sinica 2022年第7期41卷 97-112页

作者： Jichao Wang Peidong Sun Zhihong Liao Fan Bi Guiyan Liu College of Science China University of PetroleumQingdao266580China National Meteorological Information center Beijing100081China north china sea marine forecasting center of state oceanic administration Qingdao266061China Shandong Provincial Key Laboratory of marine Ecological Environment and Disaster Prevention and Mitigation Qingdao266061China

Reasonably understanding of the long-term wave characteristics is very crucial for the ocean engineering.A feedforward neural network is operated for interpolating ERA5 wave reanalysis in this study,which embodies a detailed record from 1950 onwards.The spatiotemporal variability of wave parameters in the Bohai sea,especially the significant wave height(SWH),is presented in terms of combined wave,wind wave and swell by employing the 71 years(1950–2020)of interpolated ERA5 reanalysis.Annual mean SWH decreases at−0.12 cm/a estimated by Theil-Sen estimator and 95th percentile SWH reflecting serve sea states decreases at−0.20 cm/a.Inter-seasonal analysis shows SWH of wind wave has steeper decreasing trend with higher slopes than that of swell,especially in summer and winter,showing the major decrease may attribute to the weakening of monsoon.The inner Bohai sea reveals a general decreasing trend while the intersection connecting with the Yellow sea has the lower significance derived by Mann-Kendall test.Meanwhile,95th percentile SWH decreases at a higher rate while with a lower significance in comparison with the mean state.The frequencies of mean wave directions in sub-sector are statistically calculated to find the seasonal prevailing directions.Generally,the dominant directions in summer and winter are south and north.A similar variation concerning to SWH,the trend of the mean wave period is provided,which also shows a decrease for decades.

关键词： wave characteristic wind wave swell long-term trend Bohai sea

Applicability evaluation of ERA5 wind and wave reanalysis data in the South china sea

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Journal of Oceanology and Limnology 2023年第2期41卷 495-517页

作者： Rongwei ZHAI Caijing HUANG Wei YANG Ling TANG Wenjing ZHANG South china sea Information center of state oceanic administration Guangzhou 510310China Key Laboratory of marine Environmental Survey Technology and Application Ministry of Natural ResourcesGuangzhou 510300China South china sea marine Surveying and Technology center State Ocean AdministrationGuangzhou 510300China

Wind and wave data are essential in climatological and engineering design applications.In this study,data from 15 buoys located throughout the South china sea(SCS)were used to evaluate the ERA5 wind and wave data.Applicability assessment are beneficial for gaining insight into the reliability of the ERA5 data in the SCS.The bias range between the ERA5 and observed wind-speed data was-0.78-0.99 m/s.The result indicates that,while the ERA5 wind-speed data underestimation was dominate,the overestimation of such data existed as well.Additionally,the ERA5 data underestimated annual maximum wind-speed by up to 38%,with a correlation coefficient>0.87.The bias between the ERA5 and observed significant wave height(SWH)data varied from-0.24 to 0.28 m.And the ERA5 data showed positive SWH bias,which implied a general underestimation at all locations,except those in the Beibu Gulf and centralwestern SCS,where overestimation was observed.Under extreme conditions,annual maximum SWH in the ERA5 data was underestimated by up to 30%.The correlation coefficients between the ERA5 and observed SWH data at all locations were greater than 0.92,except in the central-western SCS(0.84).The bias between the ERA5 and observed mean wave period(MWP)data varied from-0.74 to 0.57 s.The ERA5 data showed negative MWP biases implying a general overestimation at all locations,except for B1(the Beibu Gulf)and B7(the northeastern SCS),where underestimation was observed.The correlation coefficient between the ERA5 and observed MWP data in the Beibu Gulf was the smallest(0.56),and those of other locations fluctuated within a narrow range from 0.82 to 0.90.The intercomparison indicates that during the analyzed time-span,the ERA5 data generally underestimated wind-speed and SWH,but overestimated MWP.Under non-extreme conditions,the ERA5 wind-speed and SWH data can be used with confidence in most regions of the SCS,except in the central-western SCS.

关键词： ERA 5 reanalysis data wind speed significant wave height mean wave period South china sea(SCS)