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Vertical distribution of nutrient tracers in the western Arctic Ocean and its relationship to water structure and biogeochemical processes

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Acta Oceanologica Sinica 2020年第9期39卷 109-114页

作者： Yanpei Zhuang Hongliang Li haiyan jin Shengquan Gao Jianfang Chen Yangjie Li Youcheng Bai Zhongqiang Ji Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China

During the 3rd Chinese National Arctic Research Expedition cruise in the summer of 2008,nutrients(NO3^-,NO2^-,SiO3^2-,and PO4^3-)and dissolved oxygen were measured in the western Arctic Ocean,to derive the vertical distribution of nutrient tracers and its relationship to water structure and biogeochemical *** nutrient data show that surface waters had the lowest NO3^-/PO4^3-(mean of 0.5)and SiO3^2-/PO3^-(mean of 2.8)values in the water column,suggesting an excess of *** Bering Shelf water(wBSW)had high Si^*(16.7μmol/L;Si^*=[Si(OH)4]–[NO3^-])with negative N^*(−11.7μmol/L;N^*=[PO4^3-]−16[PO4^3-]+3.5μmol/L)in the water column,indicating nitrate *** warm Atlantic layer had positive N^*(0.8μmol/L)and negative Si^*(−5.4μmol/L)compared with Pacific source *** vertical distribution of nutrients indicates that wBSW can be characterized by N^* minimum and Si^* *** contrast,minima of Si^* and SiO3^2-/PO4^3- below 200 m indicate the distribution of Atlantic warm water.

关键词： nutrients N^* Si^* Canada Basin Arctic Ocean

Concentration maxima of methane in the bottom waters over the Chukchi Sea shelf:implication of its biogenic source

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Advances in Polar Science 2022年第3期33卷 235-243页

作者： LI Yuhong ZHANG Jiexia YE Wangwang jin haiyan ZHUANG Yanpei ZHAN Liyang Key Laboratory of Global Change and Marine-Atmospheric Chemistry(GCMAC)of Ministry of Natural Resources(MNR) Third Institute of Oceanography(TIO)MNRXiamen 361005China Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyMNRHangzhou 310012China Polar and Marine Research Institute Jimei UniversityXiamen 361021China

Knowledge about the distribution of CH_(4)remains insufficient due to the scarcity of data in the Arctic *** conducted shipboard observations over the Chukchi Sea shelf(CSS)in the western Arctic Ocean in September 2012 to obtain the distribution and source characteristics of dissolved CH_(4)in *** oceanographic data indicated that a salinity gradient generated a pronounced pycnocline at depths of 20-30 *** vertical diffusion of biogenic elements was restricted,and these elements were trapped in the bottom ***,high CH_(4)concentrations were measured below the pycnocline,and low CH_(4)concentrations were observed in the surface *** maximum concentrations of nutrients simultaneously occurred in the dense and cold bottom waters,and significant correlations were observed between CH_(4)and SiO_(3)^(2-),PO_(4)^(3-),NO_(2)^(-),and NH_(4)^(+)(p<0.01,n=44).These results suggest that the production of CH_(4)in the CSS has a similar trend as that of nutrient regeneration and is probably associated with the degradation of organic *** high primary productivity and high concentration of organic matter support the formation of biogenic CH_(4)in the CSS and the subsequent release of CH_(4)to the water column.

关键词： Chukchi Sea shelf methane sources nutrient organic carbon organic matter

Composition of algal pigments in surface freshen layer after ice melt in the central Arctic

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Acta Oceanologica Sinica 2017年第8期36卷 122-130页

作者： ZHUANG Yanpei jin haiyan GU Fan ZHANG Yang BAI Youcheng JI Zhongqiang LU Yong CHEN lianfang Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China

Seasonal meltwater input creates a thin freshen layer in surface seawater under ice, which largely shifts the algae assemblages. Our recent observation of photosynthetic pigments in the high Arctic showed that ice bottom and 5 m of seawater under ice contained relatively high concentration of fucoxanthin, while chlorophyll b and lutein were the major diagnostic pigments in ice-water interface and 0 m of seawater under ice. Additionally, a notable change of dominant phytoplankton occurred in the top 5 m of seawater under ice, from chlorophytes-dominated at surface to diatoms-dominated at 5 m depth, which might attribute to the sharp salinity gradient （salinity from 12.5 to 28.1） in the surface seawater under ice. Our results imply that phytoplankton community in surface layer under ice would become more chlorophytes in the future warming Arctic Ocean.

关键词： the Arctic Ocean seawater under ice pigments nutrients phytoplankton community

Distribution and Sources of Organic Matter in Surface Sediments of the Northern Bering and Chukchi Seas by Using Bulk and Tetraether Proxies

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Journal of Ocean University of China 2019年第3期18卷 563-572页

作者： JI Zhongqiang jin haiyan STEIN Ruediger LI Zhongqiao BAI Youcheng LI Hongliang ZHANG Yang CHEN Jianfang Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Second Institute of Oceanography Ministry of Natural Resources Hangzhou 310012 China State Key Laboratory of Satellite Ocean Environment Dynamics Hangzhou 310012 China Alfred Wegener Institute Helmholtz Center for Polar and Marine Research Bremerhaven 27568 Germany

The organic matter (OM) preserved in Arctic Ocean sediments is of great importance to the global carbon budget. How-ever, works that apply multiple proxies to determine the distribution and concentration of organic carbon (OC) in the surface sedi-ments of the northern Bering and Chukchi Seas remain limited. Here a multiproxy approach based on bulk OM parameters and the branched vs. isoprenoid tetraether (BIT) index was used to investigate the distribution and sources of OM in the surface sediments of the northern Bering and Chukchi Seas. Binary and ternary mixing models were applied to trace the contribution of different OC sources to the total OC in the study area. The δ13C values of the sediments provided by the binary model showed that the proportion of terrestrial OC fell in the range of 27.4%–79.8% (46.2% on average). The BIT index returned the lowest fraction (4.8%–27.3%, 12.0% on average). The ternary mixing model was employed to determine the plant-, soil-, and marine-derived fractions of the total OM. The ternary model showed that 11.5%±6.3%, 31.4%±9.5%, and 57.1%±12.4% of OM in the sediment of the study area was derived from soil, plants, and marine sources, respectively. The differences in OM composition between the west and east sides of the Chukchi Sea were controlled by OM inputs from key water masses (i.e., Anadyr Water and Alaska Coastal Water), river discharge, and the nutrient supply from the Pacific inflow that supports marine productivity.

关键词： northern Bering Sea Chukchi Sea organic matter GDGTs bulk parameters

Grain size composition and transport of sedimentary organic carbon in the Changjiang River(Yangtze River) Estuary and Hangzhou Bay and their adjacent waters

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Acta Oceanologica Sinica 2015年第10期34卷 46-56页

作者： ZHANG Weiyan jin haiyan YAO Xuying JI Zhongqiang ZHANG Xiaoyu YU Xiaoguo ZHANG Fuyuan GAO Aigen Key Laboratory of Submarine Geosciences State Oceanic Administration Second Institute of Oceanography State Oceanic Administration Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Department of Earth Sciences Zhejiang University

Surface sediments from the Changjiang River （Yangtze River） Estuary, Hangzhou Bay, and their adjacent waters were analyzed for their grain size distribution, organic carbon （OC） concentration, and stable carbon isotope composition （δ13C）. Based on this analysis, about 36 surface sediment samples were selected from various environments and separated into sand （〉0.250 ram, 0.125-0.250 ram, 0.063-0.125 mm） and silt （0.025-0.063 mm） fractions by wet-sieving fractionation methods, and further into silt- （0.004-0.025 mm） and clay-sized （〈0.004 mm） fractions by centrifugal fractionation. Sediments of six grain size categories were analyzed for their OC and 613C contents to explore the grain size composition and transport paths of sedimentary OC in the study area. From fine to coarse fractions, the OC content was 1.18%, 0.51%, 0.46%, 0.42%, 0.99%, and 0.48%, respectively, while the δ13C was -21.64‰, -22.03‰, -22.52‰, -22.46‰, -22.36‰, and -22.28%0, respectively. In each size category, the OC contribution was 42.96%, 26.06%, 9.82%, 5.75%, 7.09%, and 8.33%, respectively. The OC content in clay and fine silt fractions （〈0.025 ram） was about 69.02%. High OC concentrations were mainly found in offshore modern sediments in the northeast of the Changjiang River Estuary, in modern sediments in the lower estuary of the Changjiang River and Hangzhou Bay, and in Cyclonic Eddy modern sediments to the southwest of the Cheju Island. Integrating the distribution of terrestrial OC content of each grain size category with the δ13C of the bulk sediment indicated that the terrestrial organic material in the Changjiang River Estuary was transported seaward and dispersed to the Cyclonic Eddy modern sediments to the southwest of the Cheju Island via two pathways： one was a result of the Changjiang River Diluted Water （CDW） northeastward extending branch driven by the North Jiangsu Coastal Current and the Yellow Sea Coastal Current, while the other one was the result of the CDW southward extendin

关键词： Changjiang River (Yangtze River) Estuary Hangzhou Bay grain size composition organic carbon,material transport

Overlooked contribution of the biological pump to the Pacific Arctic nitrogen deficit

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Science China Earth Sciences 2022年第8期65卷 1477-1489页

作者： Hongliang LI Jianfang CHEN Diana RUIZ-PINO jingjing ZHANG haiyan jin Yanpei ZHUANG Youcheng BAI Jian REN Yangjie LI Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China State Key Laboratory of Satellite Ocean Environment Dynamics Hangzhou310012China Sorbonne Universités(UPMC UniversitéParis 06)-CNRS-IRD-MNHNLOCEAN Laboratory4 Place JussieuParisF-75005France Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519080China Polar and Marine Research Institute Jimei UniversityXiamen361021China

The nutrient-rich Pacific Ocean seawater that flows through the Bering Strait into the Chukchi Sea is generally considered to be the most important source of nutrients to the Arctic euphotic *** inflow is characterized by nitrogen deficit and low nitrate/phosphate(N/P)ratios;this is ascribed to sedimentary denitrification on the Chukchi shelf by preoccupant ***,the Chukchi Sea also has high primary production,which raises the question of whether the biological pump may also significantly modulate nutrient properties of the ***,we show that nitrate concentrations of the Pacific inflow gradually decrease northward in association with notable biological *** phytoplankton N/P uptake ratio was 8.8±2.27,higher than the N/P ratio of Pacific inflow water(5-6).This uptake ratio,in combination with efficient vertical nitrogen export,serves to preferentially remove nitrogen(relative to phosphorus)from upper waters,thereby further intensifying the Arctic nitrogen ***,as large as about 111.7×10^(9)mol N yr^(−1)of nitrate was extra consumed,according to the real N/P uptake ratio rather than the ratio of the Pacific inflow,which may be as great as half the nitrogen loss ascribed to sedimentary *** findings suggest that besides sedimentary denitrification,biological disproportionate utilization of nutrients in the Chukchi Sea upper water is another important contributor to the nitrogen limitation and excess phosphorus in the upper Arctic *** the rapid Arctic change era,the predicted reinforced biological carbon pump could further impact the nutrient dynamics and biogeochemical process of the Arctic Ocean.

关键词： Nitrogen deficit Biological pump Nutrient Sinking particles Arctic Ocean

Phytoplankton composition and its ecological effect in subsurface cold pool of the northern Bering Sea in summer as revealed by HPLC derived pigment signatures

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Acta Oceanologica Sinica 2014年第6期33卷 103-111页

作者： ZHUANG Yanpei jin haiyan LI Hongliang CHEN Jianfang WANG Bin CHEN Fajin BAI Youcheng LU Yong TIAN Shichao Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration College of Ocean and Meteorology Guangdong Ocean University

CHEMTAX analysis of high-performance liquid chromatography （HPLC） pigment was conducted to study phytoplankton community structure in the northern Bering Sea shelf, where a seasonal subsurface cold pool emerges. The results showed that fucoxanthin （Fuco） and chlorophyll a （Chl a） were the most abundant diagnostic pigments, with the integrated water column values ranging from 141 to 2160 μg/m2 and 477 to 5 535 μg/m2, respectively. Moreover, a diatom bloom was identified at Sta. BB06 with the standing stock of Fuco up to 9214 μg/m3. The results of CHEMTAX suggested that the phytoplankton community in the northern Bering Sea shelf was dominated by diatoms and chrysophytes with an average relative contribu- tion to Chl a of 80% and 12%, respectively, followed by chlorophytes, dinoflagellates, and cryptophytes. Dia- toms were the absolutely dominant algae in the subsurface cold pool with a relative contribution exceeding 90%, while the contribution of chrysophytes was generally higher in oligotrophic upper water. Additionally, the presence of a cold pool would tend to favor accumulation of diatom biomass and a bloom that occurred beneath the halocline would be beneficial to organic matter sinks, which suggests that a large part of the phytoplankton biomass would settle to the seabed and support a rich benthic biomass.

关键词： pigment phytoplankton community structure CHEMTAX northern Bering Sea shelf subsurface cold pool

Nitrate δ^(15)N and δ^(18)O evidence for active biological transformation in the Changjiang Estuary and the adjacent East China Sea

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Acta Oceanologica Sinica 2013年第4期32卷 11-17页

作者： CHEN Fajin CHEN Jianfang JIA Guodong jin haiyan XU Jie YANG Zhi ZHUANG Yanpei LIU Xizhen ZHANG Haisheng State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography State Oceanic Administration College of Ocean and Meteorology Guangdong Ocean University Laboratory of Marine Ecosystem and Biogeochemistry of State Oceanic Administration Second Institute of Oceanography State Oceanic Administration Key Laboratory of Marginal Sea Geology of Chinese Academy of Sciences Guangzhou Institute of Geochemistry Chinese Academy of Sciences Division of Environment Hong Kong University of Science and Technology Clear Water Bay

The Changjiang Estuary has been considered as one of the most polluted estuaries in the world due to high nitrate （NO3） input, especially in spring and summer. In this study, 6~5N and t^180 of NO3, along with other chemical parameters in this area, were measured in spring to evaluate NO3 biogeochemical processes. A simple two end-members mixing model was used to examine the relative contribution of the Changjiang River Diluted Water and marine water to NO~ sources in the Changjiang Estuary and the adjacent East Chi- na Sea. The isotopic signals show that NO3 behaved relatively and conservatively in Transect F and Transect P where assimilation was weak possibly due to vertical mixing, while active assimilation and weak nitrifi- cation occurred in Transect D. Spatial difference in assimilation was indicated by the ~ 1：1 enrichment of S 15N and 6180 in the three transects, while spatial difference in nitrification was reflected by deviations of 15N and 6180 from assimilation line. Our results suggest that the input of the Changjiang River Diluted Wa- ter promoted NO3 assimilation possibly by stratifying the water column which favored the phytoplankton growth.

关键词： Changjiang Estuary nitrate nitrogen isotope oxygen isotope

Network Delay Model for Overlay Network Application

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International Journal of Communications, Network and System Sciences 2009年第5期2卷 400-406页

作者： Tian jin haiyan jin Department of Enterprise Management North China Electric Power University Beijing China School of Electronics and Information Engineering BeiHang University Beijing China

This paper presents a method to model network delay for overlay network application. The network topology measurement technology and network AS information is used to build up model of network delay via AS and geographic distance. Based on global Internet measurement result, we calculated the parameters of the model. Furthermore, the model verification is done by comparing on AS-MMI protocol and HMTP protocol.

关键词： Network Model Autonomous System Overlay Network