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Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china earth sciences 2008年第5期51卷 654-664页

作者： hu guang1,2, jin zhangdong1 & zhang fei3 1 state key laboratory of loess and quaternary geology, institute of earth environment, chinese academy of sciences, xi’an 710075, china 2 Graduate University of the chinese academy of sciences, Beijing 100049, china 3 College of Resources and environmental Science, Nanjing Agricultural University, Nanjing 210095, china state key laboratory of loess and quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate University of the chinese academy of sciences Beijing China College of Resources and environmental Science Nanjing Agricultural University Nanjing China

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

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Progress in quantitative research on the relationship between atmospheric oxidation and air quality

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Journal of environmental sciences 2023年第1期123卷 350-366页

作者： Yuesi Wang xin jin Zirui Liu Gehui Wang Guiqian Tang Keding Lu Bo hu Shanshan Wang Guohui Li xinqin An Chao Wang Qihou hu Lingyan He Fenfen zhang Yuanhang zhang state key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China 3 State Key Joint Laboratory or Environmental Simul ation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China state key Joint laboratory of environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China key Lab of Geophysical Information System of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Shanghai key laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Department of Environmental Science and EngineeringFudan UniversityShanghai 201203China key Lab of Aerosol Chemistry and Physics State Key Laboratory of Loess and Quaternary GeologyInstitute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China institute of Atmospheric Composition and environmental Meteorology Chinese Academy of Meteorological SciencesBeijing 100081China key Lab of environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China

Atmospheric oxidizing capacity(AOC)is an essential driving force of troposphere chemistry and self-cleaning,but the definition of AOC and its quantitative representation remain *** by national demand for air pollution control in recent years,chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC *** paper will give a brief review of these ***,AOC indexes were established that represent apparent atmospheric oxidizing ability(AOIe)and potential atmospheric oxidizing ability(AOIp)based on aspects of macrothermodynamics and microdynamics,respectively.A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing,and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the *** addition,the detection of ground or vertical profiles for atmospheric OH·,HO_(2)·,NO_(3)·radicals and reservoir molecules can now be obtained with domestic instruments in diverse ***,laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O_(3)and NO_(2),which are typical oxidants in the surface/interface atmosphere,and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies,multiphase and multi-interface conditions were ***,based on the GRAPES-CUACE adjoint model improved by chinese scholars,simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been *** numerical simulations of AOIe and AOIp were performed,and regional coordination of AOC was *** optimized plan for controlling O_(3)and PM2.5was analyzed by scenario simulation.

关键词： Atmospheric oxidizing capacity(AOC) Quantitative index Free radicals Observation and modeling Air quality

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Carbon isotope and environmental changes in lakes in arid Northwest china

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Science china earth sciences 2019年第8期62卷 1193-1206页

作者： Weiguo LIU xiangzhong LI Zheng WANG huangye WANG hu LIU Bo zhang huan zhang institute of earth environment CASState Key Laboratory of Loess and Quaternary GeologyXi’an 710061China University of chinese academy of sciences Beijing 100049China

The stable carbon isotope composition(δ13 C) of lacustrine sediments, which can record changes in past environmental conditions such as the C4/C3 terrestrial vegetation composition, has been widely used for the reconstruction of terrestrial ecosystems and global climate changes. It has also been widely used in paleolimnological studies in arid northwestern china. In recent years, however, an increasing number of studies have enriched the environmental significance reflected by the stable carbon isotope geochemistry of lakes;therefore, the interpretation of lake δ13 C variations in paleoenvironmental reconstructions should be carefully evaluated from various aspects. In this paper, previous studies from the past several decades on the lacustrineδ13 C variations in arid northwestern china were reviewed, and the possible mechanisms of the δ13 C variations were *** study will provide a reference for the application of carbon isotope geochemistry in paleoenvironmental reconstructions.

关键词： Carbon isotope Lake Arid region of northwestern china Total organic carbon Organic biomarkers

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Holocene aeolian stratigraphic sequences in the eastern portion of the desert belt(sand seas and sandy lands) in northern china and their palaeoenvironmental implications

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Science china earth sciences 2019年第8期62卷 1302-1315页

作者： xiaoping YANG Peng LIANG Deguo zhang Hongwei LI Patrick RIOUAL Xulong WANG Bing XU Zhibang MA Qianqian LIU xiaozong REN Fangen hu Yuxin HE Gang RAO Ninghua CHEN Department of Geography School of Earth SciencesZhejiang UniversityHangzhou310027China key laboratory of Cenozoic geology and environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China University of chinese academy of sciences Beijing100049China state key laboratory of loess and quaternary geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an710061China institute of chinese Historical Geography Fudan UniversityShanghai200433China School of Geography Taiyuan Normal UniversityTaiyuan030619China College of Teachers’Education Yichun UniversityYichun336000China Department of geology School of Earth SciencesZhejiang UniversityHangzhou310027China

This paper presents the environmental history and its responses to palaeoclimatic changes since the start of the Holocene in the eastern portion of the desert belt(sand seas and sandy lands) in northern china by comparing the aeolian sandpalaeosol sequences and their palaeoclimatic proxies. The optically stimulated luminescence(OSL) ages of the aeolian sandpalaeosol sedimentary sequences and a series of palaeoenvironmental proxies show that:(1) The large-scale dune landscape currently in the Kubuqi Sand Sea was formed during the Holocene in general;and the palaeosol was generally developed during the period of 4–2 ka, indicating conditions favorable for vegetation growth, soil development, and organic carbon accumulation due to increased precipitation or effective moisture and weakened aeolian activities;the large-scale expansion of dunes in the recent 2 ka is closely linked to human activities. The variable discharge of the Yellow River with diversions for irrigation may have resulted in a more consistent supply of aeolian particles for dune field expansion.(2) The dune landscape of the hunshandake Sandy Land was likely formed around 12 ka, and before this, the western part of the hunshandake Sandy Land would have been covered by a single large lake;it was obviously wetter than today in the sandy land during the period of 9.6–3 ka and the palaeosols were developed at the same time. But the aeolian activities have not been completely dormant in this long-lasting wetter epoch;because the Holocene wetter period was likely time-transgressive across the region.(3) The palaeosol of the hulunbuir Sandy Land began to develop as early as 14.5 ka, probably continuing until the last 2 ka. The palaeosol development of various dune fields in the eastern portion of the desert belt(sand seas and sandy lands) in northern china is spatially heterogeneous, and even the palaeosol development time in different locations within each sandy land is inconsistent. During the middle Holocen

关键词： Sand sea Sandy land,environmental evolution,Kubuqi,hunshandake,hulunbuir

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布哈河流域不同时间尺度下土壤侵蚀对气候变化的响应特征

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地球环境学报 2021年第3期12卷 279-287页

作者：胡雅丹张飞范宣梅郁文龙成都理工大学地质灾害防治与地质环境保护国家重点实验室成都610059 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061

全球气候变暖极大地影响了地表侵蚀过程,但影响机制尚无统一定论。河流悬浮物是示踪地表侵蚀的常用手段。本文通过分析青海湖流域最大河流布哈河2008—2015年的日径流量、悬浮物浓度、气温及降雨数据,讨论了该流域在日、月以及季节尺度... 详细信息

全球气候变暖极大地影响了地表侵蚀过程,但影响机制尚无统一定论。河流悬浮物是示踪地表侵蚀的常用手段。本文通过分析青海湖流域最大河流布哈河2008—2015年的日径流量、悬浮物浓度、气温及降雨数据,讨论了该流域在日、月以及季节尺度下土壤侵蚀对气候变化的响应特征。结果表明:降雨是半干旱布哈河流域土壤侵蚀的主要控制因素,气温通过影响冻融作用控制侵蚀行为。此外,该流域的土壤侵蚀具有明显的季节性差异,大部分的侵蚀发生在雨季。最重要的是,冻融作用导致春季解冻期/雨季前期产生额外的沉积物累积,表现为在相同流量下,沉积物输出明显高于雨季后期。上述结果对深刻认识全球变暖背景下侵蚀的响应机制具有重要的作用。

关键词：河流悬浮物冻融作用侵蚀响应气候变化布哈河流域

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2000—2015年中国陆地生态系统蒸散时空变化及其影响因素

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生态学报 2019年第13期39卷 4697-4709页

作者：牛忠恩胡克梅何洪林任小丽张黎葛蓉李攀郑涵朱晓波曾纳中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室北京100101 中国科学院大学北京100049 大连海事大学大连116026 中国科学院地球化学研究所贵阳550002 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061 西南大学地理科学学院遥感大数据应用重庆市工程研究中心重庆400715

准确量化区域蒸散时空格局及其影响因素对理解陆地生态系统碳水循环具有十分重要的意义。近年来中国经历了严重的空气污染及气候波动,亟须探讨蒸散的时空变化及其影响因素。基于PT-JPL(Priestly Taylor Jet Propulsion laboratory)模型... 详细信息

准确量化区域蒸散时空格局及其影响因素对理解陆地生态系统碳水循环具有十分重要的意义。近年来中国经历了严重的空气污染及气候波动,亟须探讨蒸散的时空变化及其影响因素。基于PT-JPL(Priestly Taylor Jet Propulsion laboratory)模型,集成遥感数据和气象数据模拟了中国陆地生态系统2000 2015年蒸散,并分析其时空变化及影响因素。结果表明:1)参数优化后PT JPL模型可解释蒸散年际变化的68%,优于原始模型及MODIS蒸散产品;2)中国地区多年平均蒸散为440.16mm/a,呈东南沿海到西北内陆逐渐递减的空间格局;3)2000 2015年蒸散整体呈轻微下降趋势(slope=6.48Gt/a,P=0.17),但具有年代际差异,2000 2010年中国地区蒸散呈显著下降趋势(slope=21.05,P2010 2015年呈轻微上升趋势(slope=10.48,P=0.71),各地区均无显著变化趋势;4)辐射主导了蒸散的年代际差异,分别解释了2010年前后蒸散下降及上升趋势的51.45%、85.26%。蒸散呈显著变化趋势的内蒙古地区、黄土高原地区及青藏地区主要受辐射控制,甘新地区主要受降水和温度的影响。

关键词：蒸散 PT-JPL模型时空格局中国陆地生态系统

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