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Science China Earth Sciences 2020年第4期63卷 602-614页

作者： Juan du Mark BASKARAN jinzhou du State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Department of Geology Wayne State UniversityDetroit 48202USA

Atmospherically-delivered ~7Be,^(210)Po and ^(210)Pb in bulk precipitation and air samples collected around the globe have provided valuable quantification on the rates of removal, as well as proportional mixing of attendant air masses;however, such studies during thunderstorm and typhoon events are limited. We report the first continuous time-series rainwater sampling and analysis of ~7Be,^(210)Pb and ^(210)Po from two typhoons and one thunderstorm during 2015 summer in Shanghai. The depositional fluxes within individual rain events of typhoons and thunderstorms varied by a factor of 10 for ~7Be, 5.7 for ^(210)Pb, 7.4 for ^(210)Po,and 7.0 for ~7Be/^(210)Pb activity ratios(AR). Such large observed variations in the depositional fluxes of ~7Be,^(210)Pb,^(210)Po and ~7Be/^(210)Pb activity ratios were attributed to air masses injected from surrounding high pressure system adjoining the typhoon to low pressure system within the typhoon. Based on ~7Be/^(210)Pb activity ratios, we estimated the variations in the fraction of maritime and continental air masses into the typhoon. Observed constancy in the ^(210)Po/^(210)Pb AR indicates that the residence times of air masses contributing to the typhoon during heavy rain are similar. From a synthesis of global fallout of ~7Be and ^(210)Pb during pulse events(precipitation≥50 mm from single rainout event), we quantify the importance of pulse events in the atmospheric fallout of these radionuclides.

关键词： 7Be 210Pb 210Po Typhoon Thunderstorm Air masses intrusions

Radium-traced nutrient outwelling from the Subei Shoal to the Yellow Sea:Fluxes and environmental implication

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Acta Oceanologica Sinica 2022年第6期41卷 12-21页

作者： Jian’an Liu Dongyan Liu jinzhou du State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China

The Subei Shoal is the largest sandy ridge in the southern Yellow Sea and is important source for nutrient loading to the ***,the nutrient fluxes in the Subei Shoal associated with eddy diffusion and submarine groundwater discharge(SGD)were assessed to understand their impacts on the nutrient budget in the Yellow *** on the analysis of 223 Ra and 224 Ra in the field observation,the offshore eddy diffusivity mixing coefficient and SGD were estimated to be 2.3×10^(8)cm^(2)/s and 2.6×10^(9)m^(3)/d(16 cm/d),respectively,in the Subei *** the significant offshore decreasing gradients of nutrient in seawater of the Subei Shoal,the spatially integrated nutrient outwelling fluxes to the Yellow Sea were 262-1465μmol/(m^(2)·d)for DIN,5.2-21μmol/(m^(2)·d)for DIP and711-913μmol/(m^(2)·d)for *** to the riverine input,atmospheric deposition and mariculture,nutrient outwelling from the Subei Shoal might play an important role in nutrient budget of the Yellow *** nutrient fluxes could provide 4.1%-23%N and 1.3%-5.3%P requirements for the primary productivity,and the deviated DIN/DIP ratios have the potential to affect the growth of phytoplankton in the marine ecosystem of the Yellow Sea.

关键词： nutrient outwelling eddy diffusion submarine groundwater discharge radium isotopes Subei Shoal Yellow Sea

Submarine groundwater discharge enhances primary productivity in the Yellow Sea, China: Insight from the separation of fresh and recirculated components

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Geoscience Frontiers 2021年第6期12卷 76-89页

作者： Jianan Liu jinzhou du Xueqing Yu State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China

Submarine groundwater discharge(SGD)is being increasingly recognized as a significant source of nutrient into coastal waters,and generally comprises two components:submarine fresh groundwater discharge(SFGD)and recirculated saline groundwater discharge(RSGD).The separate evaluation of SFGD and RSGD is extremely limited as compared to the conventional estimation of total SGD and associated nutrient fluxes,especially in marginal-scale *** this study,new high-resolution radium isotopes data in seawater and coastal groundwater enabled an estimation of SGD flux in a typical marginal sea of the Yellow *** establishing 226Ra and 228Ra mass balance models,we obtained the SGD-derived radium fluxes,and then estimated the SFGD and RSGD fluxes through a two end-member *** results showed that the total SGD flux into the Yellow Sea was equivalent to approximately 6.6 times the total freshwater discharge of surrounding rivers,and the SFGD flux accounted for only 5.2%–8.8%of the total *** the nutrient concentrations in coastal fresh and saline groundwater,we obtained the dissolved inorganic nutrient fluxes(mmol m^(-2) yr^(-1))to be 52–353 for nitrogen(DIN),0.21–1.4 for phosphorus(DIP),34–226 for silicon(DSi)via SFGD,and 69–262 for DIN,1.0–3.9 for DIP,70–368 for DSi via RSGD,with the sum of nutrient fluxes equaling to(1.8–9.3)-fold,(1.3–5.6)-fold and(2.0–9.5)-fold of the riverine *** to the conventional estimation of the total SGD flux,the nutrient fluxes derived from the separation of SFGD and RSGD were(1.6–2.1),(1.6–1.8)and(4.0–4.9)times lower for DIN,DIP and DSi,respectively,indicating that the estimates by separating SFGD and RSGD could be conservative and representative results of the Yellow ***,we suggested that SGD played an important role in nutrient sources among all the traditional nutrient inputs sources,providing 15%–48%,33%–68%and 14%–43%of the total DIN,DIP and DSi input fluxes into the Yellow Sea,and the high nutrien

关键词： Submarine fresh groundwater discharge Recirculated saline groundwater discharge Nutrient fluxes Primary productivity Yellow Sea

Distribution of gamma-ray radionuclides in surface sediments of the KongsQorden, Arctic: Implications for sediment provenance

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Acta Oceanologica Sinica 2022年第1期41卷 21-29页

作者： Sheng Zeng Binbin Deng Jinlong Wang Juan du jinzhou du State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Monitoring Center of Aquatic Environment of Pearl River Basin Guangzhou 510611China Research Centre for Eco-Environmental Engineering Dongguan University of TechnologyDongguan 523808China

The Kongsfjorden is highly sensitive region to climate variability,however,the study of gamma-ray radionuclides in related areas is relatively *** this study,the grain size,total organic carbon(TOC),13 Corg isotopes,and specific activities of seven gamma nuclides were analysed in surface sediments of the Kongsfjorden in the Arctic during the summer of *** specific activities of 210 Pb_(ex),137 Cs,238 U,226 Ra,228 Ra,228 Th,and 40 K were 12–256 Bq/kg,0–3.8 Bq/kg,25–42 Bq/kg,24–38 Bq/kg,22–40 Bq/kg,22–40 Bq/kg,and 354–738 Bq/kg,respectively,with average values of(121±94)Bq/kg,(2.0±1.2)Bq/kg,(34±6)Bq/kg,(32±4)Bq/kg,(32±6)Bq/kg,(33±6)Bq/kg,and(611±119)Bq/*** study observed a significant positive correlation(r=0.845,p<0.05)between TOC and 210 Pb_(ex),highlighting the strong influence of organic matter on the distribution of 210 Pb_(ex).The boundary scavenging of210 Pb from the open sea contributed 27.5%–46.2%to the total 210 Pb_(ex) in the sediments of the outer *** grain size was an important factor affecting the activity distribution of several radionuclides(238 U,228 Ra,228 Th,226 Ra,and 40 K).The specific activity of 137 Cs indicated the transport of terrestrial materials from the exposed area of the *** sediments in the Kongsfjorden were derived from various material contributions of glacial meltwater debris,glacial rivers,bare soil,atmospheric deposition,and marine *** study explains the source of the Kongsfjorden sediment and the distribution characteristics of radionuclides,and illustrateas the main factors affecting the distribution of radionuclides,which provides a reference for the behavior of polar radionuclides in future research.

关键词： Kongsfjorden sediment TOC radionuclide sediment source

Distinguishing the main components of submarine groundwater and estimating the corresponding fluxes based on radium tracing method—taking the Maowei Sea for example

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Acta Oceanologica Sinica 2023年第8期42卷 1-23页

作者： Linwei Li jinzhou du Xilong Wang Yanling Lao State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 201100China Guangxi Key Laboratory of Marine Environmental Change and Disaster in the Beibu Gulf Beibu Gulf UniversityQinzhou 535011China School of Geographic and Environmental Sciences Tianjin Normal UniversityTianjin 300387China College of Resources and Environment Beibu Gulf UniversityQinzhou 535011China

Submarine groundwater discharge(SGD)is an important part in the land-sea interactions,which mainly contains three components:submarine fresh groundwater discharge(SFGD),tidal flat recirculated saline groundwater discharge(tidal flat RSGD)and subtidal recirculated saline groundwater discharge(subtidal RSGD).In order to make a more accurate assessment of the impact of SGD on coastal ecological environment,it is necessary to distinguish the main components of *** this study,the Maowei Sea,located in the northern part of the Beibu Gulf,was selected as the study *** on the radium(Ra)tracing method,we present a new analytical method for distinguishing the three main components of SGD in this area combined with field *** average daily flow along the coastline of the Maowei Sea of tidal flat RSGD was slightly higher than that of SFGD,and both two were on the magnitude of 1×10^(5)m^(3)/*** average daily flow for the subtidal RSGD of the entire subtidal zone of the Maowei Sea reached to the magnitude of 1×10^(6)-1×10^(7)m^(3)/*** long-term variation trend of terrestrial SGD is a valuable information for the study of the influence of terrigenous material on the coastal ecological *** on the results of four sampling periods,it is found that the fluxes of SFGD and tidal flat RSGD in the Maowei Sea had good linear correlation with the net *** an example,January 2015 to August 2022 were selected as the study periods,and the variation trends of SFGD and tidal flat RSGD were calculated by linear function with net precipitation as the independent *** results showed that the flux of tidal flat RSGD was slightly higher than that of SFGD,and the difference between the two is larger in flood season while smaller in dry *** general,in the coastal range of China,the total SGD flux in the Maowei Sea area is at a high level,and the SFGD flux is at a medium level.

关键词： submarine groundwater discharge bottom sediment radium tracing method offshore transport long-term monitoring

Porewater-derived dissolved inorganic carbon and nutrient fluxes in a saltmarsh of the Changjiang River Estuary

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Acta Oceanologica Sinica 2021年第8期40卷 32-43页

作者： Xiaogang Chen jinzhou du Xueqing Yu Xiaoxiong Wang State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Key Laboratory of Coastal Environment and Resources of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024China Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhou 310024China Institute of Eco-Chongming(IEC) Shanghai 202162China

Saltmarshes are one of the most productive ecosystems,which contribute significantly to coastal nutrient and carbon ***,limited information is available on soil nutrient and carbon losses via porewater exchange in ***,porewater exchange and associated fluxes of nutrients and dissolved inorganic carbon(DIC)in the largest saltmarsh wetland(Chongming Dongtan)in the Changjiang River Estuary were *** exchange rate was estimated to be(37±35)cm/d during December 2017 using a radon(^(222)Rn)mass balance *** porewater exchange delivered 67 mmol/(m^(2)·d),38 mmol/(m^(2)·d)and 2690 mmol/(m^(2)·d)of dissolved inorganic nitrogen(DIN),dissolved silicon(DSi)and DIC into the coastal waters,*** dominant species of porewater DIN was NH_(4)^(+)(>99%of DIN).However,different with those in other ecosystems,the dissolved inorganic phosphorus(DIP)concentration in saltmarsh porewater was significantly lower than that in surface water,indicating that saltmarshes seem to be a DIP sink in Chongming *** porewater-derived DIN,DSi and DIC accounted for 12%,5%and 18%of the riverine inputs,which are important components of coastal nutrient and carbon ***,porewater-drived nutrients had obviously high N/P ratios(160–3995),indicating that the porewater exchange process may change the nutrient characteristics of the Changjiang River Estuary and further alter the coastal ecological environment.

关键词： porewater exchange coastal wetlands saltwater intrusion nitrogen cycle blue carbon Changjiang River Estuary

Characterization of dissolved organic matter in submarine groundwater from a salt marsh in Chongming Island,China

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Journal of Oceanology and Limnology 2022年第1期40卷 128-141页

作者： Tangrong HE Fenfen ZHANG Yali WANG Xiaogang CHEN jinzhou du State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Institute of Eco-Chongming(IEC) Shanghai 202162China Key Laboratory of Coastal Environment and Resources of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024China

Salt marshes are research hotspots of the carbon cycle in coastal zones because large amounts of atmospheric carbon dioxide is fi xed by salt marshes vegetation and stored in its biomass and *** organic carbon(DOC)in submarine groundwater(well water and pore water)in salt marshes plays an important role in advective exchange between the salt marshes and coastal ***,the molecular characteristics of DOC in salt marsh groundwater are poorly understood because of the complex DOC structures and hydrodynamic *** this study,fl uorescent components and refractory DOC(RDOC)in submarine groundwater from a salt marsh(Chongming Island,China)and adjacent coastal water were characterized by fl uorescence spectroscopy and nuclear magnetic resonance *** fl uorescent components identifi ed by parallel factor analysis indicated that humic-like substances dominated the chromophoric dissolved organic matter in the submarine *** chromophoric dissolved organic matter and dissolved organic matter in the submarine groundwater had non-conservative behaviors because of additions from terrestrial humic *** nuclear magnetic resonance spectra indicated that bioactive substances(carbohydrates)contributed only 13.2%-14.8%of the dissolved organic matter in the submarine groundwater but carboxyl-rich alicyclic molecules(CRAMs),the main components of RDOC,contributed 64.5%of the dissolved organic *** and CRAMs contributed 16.4%and 61.7%of the dissolved organic matter in the coastal water,similar to the contributions for submarine *** DOC concentration in submarine groundwater was 386±294μmol/L,which was signifi cantly higher than that in coastal water(91±19μmol/L).The high DOC concentrations and>60%relative RDOC content suggested that submarine groundwater may be an important source of RDOC to coastal *** information will be helpful for estimating the climate eff ects of salt marsh blue carbon.

关键词： submarine groundwater dissolved organic carbon fl uorescence refractory dissolved organic carbon salt marsh Chongming Island

Particulate organic carbon export flux by ^(234)Th/^(238)U disequilibrium in the continental slope of the East China Sea

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Acta Oceanologica Sinica 2013年第10期32卷 67-73页

作者： BI Qianqian du jinzhou WU Ying ZHOU Jing ZHANG Jing State Key Laboratory of Estuarine and Coastal Research East China Normal University

234Th is widely used to quantify the magnitude of upper ocean particulate organic carbon （POC） export in oceans. In the present work, the rates of particulate organic carbon export were measured based on the distribution patterns of 234Th/238U disequilibrium in the water column within the continental slope of the East China Sea （ECS） during May 2011. The profiles of particulate and dissolved 234Th activities at all three stations showed a relative deficit with respect to 238U in the upper 100 m of the water column. The dissolved 234Th scavenging rates and the particulate 234Th removal rates and their residence times were calculated by a one-dimensional steady state model. The results showed that the dissolved a34Th scavenging rates and the particulate 234Th removal rates ranged from 12.4-61.4 dpm/（m3.d） and from 3.8-21.8 dpm/（m3.d）, respectively. The residence times of dissolved and particulate 234Th were in the range of 3.4-158 d and 63.7- 96.5 d, respectively. Combined with the measurement of POC/Z34Th ratios of suspended particles, POC export flux （calculated by carbon） from the euphotic zone was estimated in the study region, which ranged from 4.14-14.7 mmol/（m2 .d）, with an average of 8.21 mmol/（m3.d）, occupying 35% of the prime productivity in the study area. The results of this study can provide new information for better understanding the carbon biogeochemical cycle within the continental slope of the ECS.

关键词： 234Th/238U disequilibrium residence time POC export East China Sea (ECS)

Carbon isotopes and lignin phenols for tracing the floods during the past 70 years in the middle reach of the Changjiang River

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Acta Oceanologica Sinica 2020年第4期39卷 33-41页

作者： Zhongqiao Li Ying Wu Liyang Yang jinzhou du Bing Deng Jing Zhang State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 210012China Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China College of Environment and Resources Fuzhou UniversityFuzhou 350108China

The Lake Tian E Zhou(TEZ,an oxbow lake)was formed during the rerouting of the Changjiang River in 1972,with strong influences from the main river channel and flood ***,a sediment core was collected from the Lake TEZ for the measurements of carbon isotopes and biomarkers,including stable carbon isotopes(δ13C),radiocarbon composition(?14C),and lignin phenols,as well as lead-210 to reconstruct recent heavy flood events over the past 70 *** the 24–26 cm interval,the sediment contained the highest OC%,TN%,and lignin phenols content,as well as significantly depleted 13C but enriched 14C,corresponding to the extreme flood event in *** addition,statistics from t-test showed that lignin phenols normalized to OC(Λ8),the concentration of 3,5-dihydroxy benzoic acid(3,5-BD),and the ratio of p-hydroxy benzophenone to total hydroxyl phenols(PHB/HP)were all significantly different between the layers containing flood deposits and the layers deposited under normal non-flood conditions(p<0.05).These results indicate that the later three parameters are highly related to flood events and can be used as compelling proxies,along with sediment chronology,for hydrological changes and storm/flood events in the river basin and coastal marine environments.

关键词： flood record carbon isotopes lignin phenols Changjiang River Lake Tian E Zhou

Contrasting behaviors of^(210)Po,^(210)Pb and^(234)Th in the East China Sea during a severe red tide:Enhanced scavenging and promoted fractionation

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Acta Oceanologica Sinica 2022年第8期41卷 5-21页

作者： Qiangqiang Zhong Linwei Li Viena Puigcorbé Dekun Huang Tao Yu jinzhou du Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China School of Science Centre for Marine Ecosystems ResearchEdith Cowan UniversityJoondalupWestern Australia 6027Australia

^(210)Po,^(210)Pb,and^(234)Th were determined in water columns of the East China Sea(ECS)to investigate their biogeochemical behaviors during a severe red tide ***^(210)^(210)radionuclides were influenced by particle content effect and particle composition based on distribution coefficient(Kd)*** suspended matter(TSM)content and Kd *** of particulate organic carbon and total suspended matter contents(POC/TSM content ratios).The peaks of mass specific activities of^(210)Po,^(210)Pb,and^(234)Th indicated that degraded particles could have an intensified enrichment ability for radionuclides compared with the surficial suspended *** factor of^(210)Po and^(210)Pb(FPo/Pb)(>1)and fractionation factor of^(210)Po and^(234)Th(FPo/Th)(>1)were much higher at algal blooming regions than that at non-blooming stations,indicating that algal blooms promoted the fractionation of^(210)Po against^(210)Pb and^(234)Th,and proving that^(210)Po exhibited a stronger affinity for biogenic particles than^(210)Pb and^(234)Th when POC content increased in the ***/^(210)Po,POC/^(210)Pb and POC/^(234)Th ratios(content/activity ratios)sharply decreased with depth in both algal bloom and non-bloom *** outbreak of algal bloom promoted the complexity of suspended particles and increased the variability of POC/tracer ratios(content/activity ratios)in the different depth of the shallow *** considerations should be taken to the difficulty of the selection of export interface and the suitable tracers when algal blooming occurs.

关键词： algal blooming East China Sea ^(210)Po ^(210)Pb ^(234)Th biogeochemical behavior