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Photo-production of dissolved inorganic carbon from dissolved organic matter in contrasting coastal waters in the southwestern Taiwan Strait, China

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Journal of Environmental Sciences 2012年第7期24卷 1181-1188页

作者： weidong Guo Liyang Yang Xiangxiang Yu weidong zhai Huasheng Hong State Key Laboratory of Marine Environmental Science Xiamen UniversityXiamen 361005China College of Oceanography and Environmental Science Xiamen UniversityXiamen 361005China

Photo-production of dissolved inorganic carbon （DIC） from chromophoric dissolved organic matter （CDOM） is an important transformation process in marine carbon cycle, but little is known about this process in Chinese coastal systems. This study investigated an estuarine water sample and a coastal seawater sample from the subtropical waters in southeast of China. Water samples were exposed to natural sunlight and the absorption and fluorescence of CDOM as well as the DIC concentration were measured in the summer of 2009. The estuarine water had higher CDOM level, molecular weight and proportion of humic-like fluorescent components than the seawater that exhibited abundant tryptophan-like fluorescent component. After a 3-day irradiation, the CDOM level decreased by 45% in the estuarine water and 20% in the seawater, accompanied with a decrease in the molecular weight and aromaticity of DOM which was inferred from an increase in the absorption spectral slope parameter. The photo-degradation rates of all the five fluorescent components were also notable, in particular two humic-like components （C4 and C5） were removed by 78% and 69% in the estuarine water and by 69% and 56% in the seawater. The estuarine water had a higher photo-production rate of DIC than the seawater （4.4 vs. 2.5 μmol/（L-day））, in part due to its higher CDOM abundance. The differences in CDOM compositions between the twO types of waters might be responsible for the higher susceptibility of the estuarine water to photo-degradation and hence could also affect the photo-production process of DIC.

关键词： dissolved inorganic carbon photo-production and -degradation chromophoric dissolved organic matter estuary seawater

Unveiling controls of the latitudinal gradient of surface pCO_(2) in the Kuroshio Extension and its recirculation regions(northwestern North Pacific)in late spring

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Acta Oceanologica Sinica 2022年第5期41卷 110-123页

作者： Chenglong Li weidong zhai Di Qi Institute of Marine Science and Technology Shandong UniversityQingdao266237China Polar and Marine Research Institute Jimei UniversityXiamen361021China Key Laboratory of Global Change and Marine-Atmospheric Chemistry of Ministry of Natural Resources Third Institute of OceanographyMinistry of Natural ResourcesXiamen361005China

In the northwestern North Pacific,annual net air-sea CO_(2) flux is greatest in the Kuroshio Extension(KE)zone,owing to its low annual mean partial pressure of CO_(2)(pCO_(2)),and it decreases southward across the *** quantify the influences of factors controlling the latitudinal gradient in CO_(2) uptake,sea surface pCO_(2) and related parameters were investigated in late spring of 2018 in a study spanning the KE,Kuroshio Recirculation(KR),and subtropical *** found that the sea-to-air pCO_(2) difference(ΔpCO_(2))was negative and at its lowest in the KE zone.ΔpCO_(2) gradually increased southward across the KR zone,and the sea surface was nearly in air-equilibrium with atmospheric CO_(2) in the subtropical *** found that northward cooling and vertical mixing were the two major processes governing the latitudinal gradient in surface pCO_(2) and ΔpCO_(2),while biological influences were relatively *** the KE zone affected by upwelling,the vertical-mixing-induced increase in surface pCO_(2) likely canceled out approximately 61%of the decrease in surface pCO_(2) caused by cooling and biological ***,the prolonged air-sea equilibration for CO_(2) and relatively short hydraulic retention time jointly led to the low surface pCO_(2) in the KE zone in ***,the cooling KE current flows out of the region before it can be re-equilibrated with atmospheric CO_(2).

关键词： partial pressure of CO_(2) temperature effect vertical mixing biological activity air-sea exchange northwestern North Pacific

Coastal acidification in summer bottom oxygen-depleted waters in northwestern-northern Bohai Sea from June to August in 2011

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Chinese Science Bulletin 2012年第9期57卷 1062-1068页

作者： zhai weidong ZHAO HuaDe ZHENG Nan XU Yi Key Laboratory for Ecological Environment in Coastal Areas （State Oceanic Administration） National Marine Environmental Monitoring Center Dalian 116023 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

Dissolved oxygen(DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August,*** the June cruise,the bottom DO was in the range of 215-290 μmol-O2 kg-1(i.e.85%-115% of the saturation level),and the bottom pH was in the range of 7.82-8.04 on the total-hydrogen-ion *** August,however,both the bottom DO and the pH had significantly declined in the northwestern-northern near-shore areas,where the water depth was no more than 35 *** lowest bottom DO was 100-110 μmol-O2 kg-1(only 44%-47% of the June DO values) in the northern near-shore area,where the bottom pH was 7.64-7.68 on the total-hydrogen-ion scale(0.16-0.20 units lower than the June pH value).The largest decreases in DO and in pH were observed in the northwestern near-shore bottom waters,corresponding to declines of 170 μmol-O2 kg-1(as high as 59% of the June DO value) and 0.29 pH units,*** greatest pH decline of 0.29 pH units meant that the total-hydrogen-ion concentration doubled in the bottom waters from June to *** on field measurements of bottom DO/pH combined with a simplified model simulation,we suggest that respiration/remineralization-derived CO2 increased the acidity in the bottom oxygen-depleted waters of northwestern-northern near-shore areas in the Bohai Sea as a result of coastal red tides and/or marine *** aquatic chemistry is suggested to be partially responsible for scallop-breeding failures in the northwestern Bohai Sea in summer 2011.

关键词：渤海中部渤海海域西北部溶解氧底部沿海夏季气耗

Spring and autumn living coccolithophores in the Bohai Sea and Yellow Sea,China

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Acta Oceanologica Sinica 2015年第10期34卷 132-146页

作者： JIN Hualong FENG Yuanyuan LI Xiaoqian zhai weidong SUN Jun College of Marine and Environmental Sciences Tianjin University of Science and Technology Tianjin Key Laboratory of Marine Resources and Chemistry Tianjin University of Science and Technology National Marine Environmental Monitoring Center State Oceanic Administration

The living coccolithophores （LCs） are an important class of calcified taxa of phytoplankton functional groups, and major producers of marine biogenic inorganic carbon, playing an important role in the marine carbon cycle. In this study, we report the two-demensional abundance, composition of LCs and its correlation with the environmental parameters in spring and autumn, in order to understand the ecological role of LCs in the Yellow Sea and the Bohai Sea. In spring, totally 9 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1 000x magnification. The dominant species were Emiliania huxleyi, Gephyrocapsa oceanica, Helicosphaera carteri, and Calcidiscus leptoporus. The abundance of coccosphores and coccoliths ranged 0-7.72 cells/mL, and 0-216.09 coccoliths/mL, with the average values of 0.21 cells/mL, and 11.36 coccoliths/mL, respectively. The Emiliania huxleyi distribution was similar to Gephyrocapsa oceanica. The highest abundance of coccoliths was observed in the east of Shandong Peninsula in northern Yellow Sea, whereas Helicosphaera carteri distributed more widely. Emiliania huxleyi and Gephyrocapsa oceanica were the two predominant species in LCs with higher abundances. The distribution of LCs was similar to that of coccoliths. In autumn, 14 taxa belonging to coccolithophyceae were identified with dominant species as Emiliania huxleyi, Gephyrocapsa oceanica, Helicosphaera carteri, Calcidiscus leptoporus and Oolithotus fragilis. The abundance of coccosphores and coccoliths ranged 0-24.69 cells/mL, and 0-507.15 coccoliths/mL, with the average values of 1.47 cells/mL, and 55.89 coccoliths/mL, respectively. The highest abundance of coccoliths was located in Qingdao coastal waters and south of the survey area. The distribution of LCs was similar to the coccoliths; in addition, LCs presented large abundance in the east of the central Yellow Sea area.

关键词： living coccolithophores Bohai Sea Yellow Sea spring autumn

Phytoplankton communities and its controlling factors in summer and autumn in the southern Yellow Sea, China

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Acta Oceanologica Sinica 2015年第2期34卷 114-123页

作者： LIU Haijiao HUANG Yajie zhai weidong GUO Shujin JIN Hualong SUN Jun College of Marine Science and Engineering Tianjin University of Science and Technology Key Laboratory for Ecological Environment in Coastal Areas of State Oceanic Administration National Marine Environmental Monitoring Center Tianjin Key Laboratory of Marine Resources and Chemistry Tianjin University of Science and Technology

The phytoplankton water samples were collected in two multidisciplinary investigations which were carried out during summer（June） and autumn（November to December） of 2011. Phytoplankton species composition and abundance data were accomplished by Uterm？hl method. The phytoplankton community was dominated by diatoms and dinoflagellates in the southern Yellow Sea（YS） in summer and autumn. In summer, Paralia sulcata and Prorocentrum dentatum were the predominated species, the cell abundance ranged from 0.074 to 107.733×103 cells/L with an average of 9.057×103 cells/L. Two phytoplankton high abundance appeared in northwest part of the survey area and the Changjiang River Estuary, respectively. In autumn, Par. sulcata became the predominant species, and the phytoplankton cell abundance ranged from 1.035×103 to 8.985×103 cells/L, the average was 3.263×103 cells/L. The phytoplankton abundance in surface layer presented the homogeneous distributions. Canonical Correspondence Analysis（CCA） method was applied for discovering the relationship between environmental factors and the common found phytoplankton species. The responses of phytoplankton to nutrients were varied between summer and autumn. The abundance of most predominant species, Par. sulcata was strongly correlated to temperature and salinity in autumn, but not the case in summer.

关键词： phytoplankton southern Yellow Sea YSCW nutrients CCA correlation

Complications of microvascular decompression in hemifacial spasm treatment Retrospective analysis of 156 cases

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Neural Regeneration Research 2008年第1期3卷 101-103页

作者： Yongfeng Sun Guanghui Dai Jun yuan weidong zhai Jianwei Zhong Tao Wang Department of Neurosurgery Beijing General Group Hospital the Chinese People＇s Armed Police Forces Beijing 100027 China

BACKGROUND： Microvascular decompression has become a well-accepted, safe method in the treatment of hemifacial spasms. However, postoperative complications exist and influence the prognosis of the disease. OBJECTIVE： This study aimed to analyze, by case review, the characteristics and regularity of microvascular decompression complications in the treatment of hemifacial spasm. DESIGN： Retrospective analysis. SETTING： Beijing General Group Hospital of the Chinese People＇s Armed Police Forces. PARTICIPANTS： A total of 156 patients with hemifacial spasm were admitted to the Department of Neurosurgery, Beijing General Group Hospital of the Chinese People＇s Armed Police Forces from June 2004 to June 2006 and recruited for this study. The patients, 57 males and 99 females, averaged 46 years of age （range 17-68-years old）. All suffered from facial innervated muscular paroxysmal and recurrent contraction, which could not be controlled by consciousness. Electromyogram demonstrated waves of fibrillation and fasciculation. Prior to admission, all patients had received other treatments. Written informed consents for treatment were obtained from all patients. This protocol was approved by the Hospital＇s Ethics Committee. METHODS： After anesthesia, a cranial bone pore was drilled below the connection of the lateral sinus and sigmoid sinus. Dura mater was dissected at the ＂⊥＂ shape and held in the air. Under microscopy, the flocculus cerebelli was lifted slightly up for convenient observation of the cerebellopontine angle. The mucous membrane was sharply separated. Corresponding vessels were identified at the root of the facial nerves and subsequently liberated and disassociated from the root exit zone. Suitably sized Teflon cotton was placed between the corresponding vessels and brain stem. MAIN OUTCOME MEASURES： Complications of microvascular decompression. RESULTS： All 156 patients participated in the final analysis. （1） Postoperatively, 66 （42%） patients presented with obvious

关键词： microvascular decompression hemifacial spasm postoperative complication

Mechanisms of carbon storage and the coupled carbon, nitrogen and sulfur cycles in regional seas in response to global change

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Science China Earth Sciences 2017年第5期60卷 1010-1014页

作者： XIE ShuCheng CHEN JianFang WANG FengPing XUN LuYing TANG Kai zhai weidong LIU JiHua MA WenTao State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences The Second Institute of Oceanography State Marine Administration of China Faculty of Life Science and Technology Shanghai Jiaotong University Institute of Oceanography Shangdong University College of Ocean and Earth Sciences Xiamen University School of Ocean and Earth Science Tongji University

*** challenges in scientific frontiers of marine carbon storage in the scenario of global change The marine carbon cycle is influenced by anthropogenic activities,affecting global climate change and casting a significant impact on ***,the complex spatiotemporal process of the marine carbon cycle results in the uncertainty in the estimation of marine carbon budget。

关键词： sulfur anthropogenic cycle scenario affecting microbial warming nutrients anaerobic Bohai

Satellite-derived surface water pCO2 and air-sea CO2 fluxes in the northern South China Sea in summer

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Progress in Natural Science:Materials International 2009年第6期19卷 775-779页

作者： Yu Zhu, Shaoling Shang, weidong zhai, Minhan Dai State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China [a]State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

An empirical approach is presented for the estimation of the partial pressure of carbon dioxide (pCO2) and air-sea CO2 fluxes in the northern South China Sea in summer using satellite-derived sea surface temperatures (SSTs), chlorophyll-a (Chl a) concentrations, and wind fields. Two algorithms were tested. The first used an SST-dependent equation, and the other involved the introduction of Chl a. Regression equations were developed for summer based on in situ data obtained in July, 2004. Using the monthly average SST and Chl a fields derived from the advanced very high resolution radiometer (AVHRR) and the SeaWiFS (sea-viewing wide field of view sensor), respectively, the monthly pCO2 fields were computed. The derived pCO2 was compared with the shipboard pCO2 observations conducted in July, 2000. This resulted in a root-mean-square error of 4.6 latm, suggesting that the satellite-derived pCO2 was in general agreement with the in situ observations. The air-sea CO2 flux was further computed with the aid of the monthly mean QuikSCAT wind speed. We contend that more shipboard data are necessary for refining the empirical algorithms and reducing the uncertainty in the results.

关键词： pCO2 Remote-sensing Northern South China Sea CO2 flux

海洋酸化与水体净碳酸钙形成/溶解的关系-以黄海冷水团为例

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海洋科学进展 2023年第4期41卷 565-576页

作者：翟惟东南方海洋科学与工程广东省实验室(珠海) 广东珠海519082

综述了黄海冷水团海洋酸化研究的进展。利用2011年、2013年和2017年在北黄海月际调查获取的碳酸盐体系数据,研究得出,北黄海冷水团的净钙化作用速率与底层水体的文石型碳酸钙饱和度正相关,而北黄海冷水团净碳酸钙生产与净碳酸钙溶解之... 详细信息

综述了黄海冷水团海洋酸化研究的进展。利用2011年、2013年和2017年在北黄海月际调查获取的碳酸盐体系数据,研究得出,北黄海冷水团的净钙化作用速率与底层水体的文石型碳酸钙饱和度正相关,而北黄海冷水团净碳酸钙生产与净碳酸钙溶解之间的临界阈值是文石型碳酸钙饱和度降至1.5~1.6。这是在中国近海首次建立起水体碳化学参数与碳酸钙过程之间的半定量关系,所确定的动物群落净钙化与净的碳酸钙溶解之间的水化学阈值对我国后续的海洋酸化监测与生态效应评估工作有一定借鉴意义。采用这一阈值,结合国家海洋局北海环境监测中心于1977年至2016年期间在北黄海西侧季节性调查断面获取的实测数据,发现北黄海冷水团的季节性酸化现象已于20世纪末开始威胁底栖贝类的净钙化作用(以秋季的平均文石型碳酸钙饱和度频繁低于1.5为标志),在2010年以后更是发生夏秋两季的海水酸化都严重威胁底栖贝类的情况(即文石型碳酸钙饱和度都低于1.5)。这说明,在我国一些近海海域部署海洋酸化相关的防灾减灾措施的需求已经十分迫切。

关键词：海洋酸化碳酸钙溶解碳酸钙饱和度生态效应评估黄海冷水团