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Boron isotopic fractionation in laboratory inorganic carbonate precipitation:Evidence for the incorpora-tion of B(OH)_3 into carbonate

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Science China Earth Sciences 2008年第12期51卷 1776-1785页

作者： XIAO YingKai1,2, LI HuaLing1,3, LIU WeiGuo4. WANG XiuFang1 & JIANG ShaoYong5 1 Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China 2 state key laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 3 Nanjing Institute of geology and Mineral Resources, Nanjing 210016, China 4.state key laboratory of loess and quaternary geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China 5 state key laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China 1. Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China 2. state key laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China 3. Nanjing Institute of geology and Mineral Resources 210016 Nanjing China 4. state key laboratory of loess and quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 5. state key laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China

A laboratory inorganic carbonate precipitation experiment at high pH of 8.96 to 9.34.was conducted, and the boron isotopic fractionations of the precipitated carbonate were measured. The data show that boron isotopic fractionation factors (αcarb-3) between carbonate and B(OH)3 in seawater range 0.937 and 0.965, with an average value of 0.953. Our results together with those reported by Sanyal and collabo-rators show that the αcarb-3 values between carbonate and B(OH)3 in solution are not constant but are negatively correlated with the pH of seawater. The measured boron isotopic compositions of carbonate precipitation (δ11Bcarb) do not exactly lie on the best-fit theoretical δ 11B4.pH curves and neither do they exactly parallel any theoretical δ 11B4.pH curves. Therefore, it is reasonable to argue that a changeable proportion of B(OH)3 with pH of seawater should also be incorporated into carbonate except for the dominant incorporation of B(OH)4. in carbonate . Hence, in the reconstruction of the paleo-pH of sea-water from boron isotopes in marine biogenic carbonates, the use of theoretical boron isotopic frac-tionation factor (α4.3) between B(OH)4. and B(OH)3 is not suitable. Instead, an empirical equation should be established.

关键词： boron isotopic fractionation biogenic carbonate B(OH)3 incorporation

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Chronology of the stratum containing the skull of the Dali Man

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Chinese Science Bulletin 2002年第15期47卷 1302-1307页

作者： YIN Gongming ZHAO Hua YIN Jinhui LU Yanchou Institute of geology China Seismological BureauBeijing 100029China state key Lab loess&quaternary {4. Chinese Academy of ScienceXi’an 710075China Institute of Hydrogeology and Environmental geology CAGS

The field investigations of geomorphology and quaternary sediment sequences show that the sediment stratigraphic profile containing the skull of the Homo sapiens Daliensis (Dali Man) at Tianshuigou trench, Jiefang Village (109°4.’E, 34.52’N ), Dali County, Shaanxi Province, is composed of the loess-paleosol sequence, 17.3 m thick, in the upper part, and the alluvial silts, fine sands and sandy gravels interbedded, 15.4.m thick, in the lower part. There are the well developed layers L1, S1, L2 and S2 in the loess-paleosol sequence of the profile, which are comparable to those of the Luochuan loess section on the basis of magnetic succeptibility measurements and IRSL dating of the loess samples. An alluvial gravel layer, where the skull of the Dali Man was discovered, is in 13 m beneath the bottom of paleosol S2, implying that, the age of the Dali Man must be older than about 24. kaBP when the paleosol S2 began to be developed. The samples of mammal animal tooth and shell fossils from the gravel layer

关键词： Dali Man stratigraphy chronology.

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Observational Characteristics of Cloud Radiative Effects over Three Arid Regions in the Northern Hemisphere

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Journal of Meteorological Research 2017年第4期31卷 654-664页

作者： Jiandong LI Tianhe WANG Ammara HABIB state key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences state key laboratory of loess and {4. geology Institute of Earth EnvironmentChinese Academy of Sciences key laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou University

Cloud–radiation processes play an important role in regional energy budgets and surface temperature changes over arid regions. Cloud radiative effects（CREs） are used to quantitatively measure the aforementioned climatic role. This study investigates the characteristics of CREs and their temporal variations over three arid regions in central Asia（CA）, East Asia（EA）, and North America（NA）, based on recent satellite datasets. Our results show that the annual mean shortwave（SW） and net CREs（SWCRE and NCRE） over the three arid regions are weaker than those in the same latitudinal zone of the Northern Hemisphere. In most cold months（November–March）, the longwave（LW）CRE is stronger than the SWCRE over the three arid regions, leading to a positive NCRE and radiative warming in the regional atmosphere–land surface system. The cold-season mean NCRE at the top of the atmosphere（TOA） averaged over EA is 4.1 W m^-2, with a positive NCRE from November to March, and the intensity and duration of the positive NCRE is larger than that over CA and NA. The CREs over the arid regions of EA exhibit remarkable annual cycles due to the influence of the monsoon in the south. The TOA LWCRE over arid regions is closely related to the high-cloud fraction, and the SWCRE relates well to the total cloud fraction. In addition, the relationship between the SWCRE and the low-cloud fraction is good over NA because of the considerable occurrence of low cloud. Further results show that the interannual variation of TOA CREs is small over the arid regions of CA and EA, but their surface LWCREs show certain decreasing trends that correspond well to their decreasing total cloud fraction. It is suggested that combined studies of more observational cloud properties and meteorological elements are needed for indepth understanding of cloud–radiation processes over arid regions of the Northern Hemisphere.

关键词： arid region cloud fraction cloud radiative effects

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Orbital-scale Asian summer monsoon variations:Paradox and exploration

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Science China Earth Sciences 2021年第4期64卷 529-544页

作者： Hai CHENG Haiwei ZHANG Yanjun CAI Zhengguo SHI Liang YI Chenglong DENG Qingzhen HAO Youbing PENG Ashish SINHA Hanying LI Jingyao ZHAO Ye TIAN Jonathan BAKER Carlos PEREZ-MEJIAS Institute of Global Environmental Change Xi'an Jiao tong UniversityXi'an 710054China state key laboratory^of loess and {4. geology1 Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China key laboratory of Karst Dynamics Ministry of Land and ResourcesInstitute of Karst GeologyChinese Academy of Geological SciencesGuilin 541004China state key laboratory of Marine geology Tongji UniversityShanghai 200092China state key laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China key laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Earth Sciences California State University Dominguez HillsCarson 90747USA

The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM.(1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr(thousand years) periodicity, while the cave oxygen-isotope(δ18 O) records reveal periodicity in an almost pure precession band(~20 kyr periodicity)—the "Chinese 100 kyr problem".(2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation(NHSI), whereas the Asian cave δ18 O records follow NHSI without a significant lag—a discrepancy termed the "sea-land precession-phase paradox". How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the "Chinese 100 kyr problem" and "sea-land precession-phase paradox".

关键词： ASM Orbital cycles Precession phase Different climatic proxies

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Spectral dispersion of cloud droplet size distributions and radar threshold reflectivity for drizzle

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Chinese Physics B 2010年第10期19卷 659-662页

作者：解小宁刘晓东 state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences Graduate University of the Chinese Academy of Sciences Department of Environmental Science and Technology School of Human Settlements and Civil Engineering Xi'an Jiaotong University

From first principles, we find that the radar threshold reflectivity between nonprecipitating clouds and precipitating clouds is strongly related to not only the cloud droplet number concentration but also the spectral dispersion of cloud droplet size distributions. The further investigation indicates that the threshold value is an increasing function of spectral dispersion and cloud droplet number concentration. These results may improve our understanding of the cloud-precipitation interaction and the aerosol indirect effect.

关键词： radar threshold reflectivity spectral dispersion cloud droplet number concentration

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Assessment of the Summer South Asian High in Eighteen CMIP5 Models

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Atmospheric and Oceanic Science Letters 2015年第1期8卷 33-38页

作者： HE Bian HU Wen-Ting state key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences

The South Asian High(SAH) is one of the most important components of the Asian summer monsoon system. To understand the ability of state-of-the-art general circulation models(GCMs) to capture the major characteristics of the SAH, the authors evaluate 18 atmospheric models that participated in the Coupled Model Intercomparison Project Phase 5/Atmospheric Model Intercomparison Project(CMIP5/AMIP). Results show that the multi-model ensemble(MME) mean is able to capture the climatological pattern of the SAH, although its intensity is slightly underestimated. For the interannual variability of the SAH, the MME exhibits good correlation with the reanalysis for the area and intensity index, but poor skill in capturing the east-west oscillation of the SAH. For the interdecadal trend, the MME shows pronounced increasing trends from 1985 to 2008 for the area and intensity indexes, which is consistent with the reanalysis, but fails to capture the westward shift of the SAH center. The individual models show different capacities for capturing climatological patterns, interannual variability, and interdecadal trends of the SAH. Several models fail to capture the climatological pattern, while one model overestimates the intensity of the SAH. Most of the models show good correlations for interannual variability, but nearly half exhibit high root-mean-square difference(RMSD) values. Six models successfully capture the westward shift of the SAH center in the interdecadal trends, while other models fail. The possible causes of the systematic biases involved in several models are also discussed.

关键词： South Asian High CMIP5 Asian summer monsoon AMIP

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Impacts of Aerosol−Radiation Interactions on the Wintertime Particulate Pollution under Different Synoptic Patterns in the Guanzhong Basin,China

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Advances in Atmospheric Sciences 2021年第7期38卷 1141-1152页

作者： Naifang BEI Xia LI Qiyuan WANG Suixin LIU Jiarui WU Jiayi LIANG Lang LIU Ruonan WANG Guohui LI School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China key laboratory of Aerosol Chemistry and Physics State Key Laboratory of Loess and Quaternary GeologyInstitute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Center for Excellence in quaternary Science and Global Change Chinese Academy of SciencesXi’an 710061China

The effects of aerosol-radiation interactions(ARI)are not only important for regional and global climate,but they can also drive particulate matter(PM)*** this study,the ARI contribution to the near-surface fine PM(PM_(2.5))concentrations in the Guanzhong Basin(GZB)is evaluated under four unfavorable synoptic patterns,including“northlow”,“transition”,“southeast-trough”,and“inland-high”,based on WRF-Chem model simulations of a persistent heavy PM pollution episode in January *** show that ARI consistently decreases both solar radiation reaching down to the surface(SWDOWN)and surface temperature(TSFC),which then reduces wind speed,induces sinking motion,and influences cloud formation in the ***,large differences under the four synoptic patterns still *** average reductions of SWDOWN and daytime TSFC in the GZB range from 15.2%and 1.04.C in the case of the“transition”pattern to 26.7%and 1.69°C in the case of the“north-low”pattern,***,ARI suppresses the development of the planetary boundary layer(PBL),with the decrease of PBL height(PBLH)varying from 18.7%in the case of the“transition”pattern to 32.0%in the case of the“north-low”*** increase of daytime near-surface PM_(2.5)in the GZB due to ARI is 12.0%,8.1%,9.5%,and 9.7%under the four synoptic patterns,*** analyses also reveal that when near-surface PM_(2.5)concentrations are low,ARI tends to lower PM_(2.5)concentrations with decreased PBLH,which is caused by enhanced divergence or a transition from divergence to convergence in an *** contributes 15%-25%toward the near-surface PM_(2.5)concentrations during the severe PM pollution period under the four synoptic patterns.

关键词： aerosol-radiation interactions wintertime particulate pollution synoptic patterns Guanzhong Basin

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Boron isotope geochemistry of Bangor Co Salt Lake(central Tibet):implications for boron origin and uneven mixing of lake water

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Acta Geochimica 2022年第5期41卷 731-740页

作者： Bin-Kai Li Mao-Yong He Hai-Zhou Ma Huai-De Cheng Lian-Min Ji Qinghai Provincial key laboratory of geology and Environment of Salt Lakes Qinghai Institute of Salt LakesChinese Academy of Sciences810008 XiningQinghaiChina state key laboratory of loess and {4. geology Institute of Earth EnvironmentChinese Academy of Sciences710061 Xi’anChina University of the Chinese Academy of Sciences 100049 BeijingChina

Boron is an essential,widely used,micronutrient element and is abundant in salt lakes on the Qinghai-Tibet *** origin and distribution of boron brine deposits on the Qinghai-Tibet Plateau is an important foundation for B resource formation,evolution,and enrichment,which have long been the subject of *** boron isotope system is a sensitive geochemical tracer,making it useful for eff ectively and precisely tracking a wide range of geological processes and *** study investigates the major cations,[B],andδB values of samples(lake brine,river waters,and cold spring water)from the Bangor Co Lake which is a typical salt lake rich in boron in Tibet,*** are magnitude-scale diff erences in[B]among diff erent sample types:river samples4.62‰,and theδB values of river water samples are basically in the distribution range of those of Bangor Co *** indicates that the sources of boron in Bangor Co Lake are mainly the recharge water with higherδB values and spring water with lowerδB values,and the boron sources and the uneven mixing of lake water are two reasons that account for the large change in theδB value of Bangor Co Lake.

关键词： Tibet Bangor Co salt lake Boron isotope Origin Fractionation processes

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The forecast of seasonal precipitation trend at the north Helan Mountain and Baiyinaobao regions, Inner Mongolia for the next 20 years

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Chinese Science Bulletin 2004年第4期49卷 410-415页

作者： LIU Yu V. Shishov SHI Jiangfeng E. Vaganov SUN Junyan CAI Qiufang I. Djanseitov AN Zhisheng state key laboratory of loess and {4. geology The Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075China Sukachev Institute of Forest Russian Academy of Sciences Kras-noyarsk 660036 Russia

By using Caterpillar-SSA analysis method, through the process of embedding, singular value decompo-sition, grouping and diagonal averaging, the seasonal pre-cipitation trend at north Helan Mountain and Baiyinaobo regions, Inner Mongolia for the next 20 years is forecasted. The results show an increasing precipitation trend from 1992 to 2004. In the subsequent decade the precipitation should reduce quickly, and it will reach a minimum near 2012 to 2014.in both regions. The drought caused by the decrease of the precipitation from May to July in the north Helan Mountain area during the period of 2013—2014.is probably quite similar to that around 1929. Further, the period of pre-cipitation gradual increase follows in the researched regions.

关键词：贺兰山内蒙古季降水量预测气候变化

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A preliminary study of small-mass radiocarbon sample measurement at Xi'an-AMS

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Chinese Physics C 2015年第3期39卷 45-52页

作者：付云翀周卫健杜花程鹏赵晓雷刘起卢雪峰赵稳年 state key laboratory of loess and {4. geology Institute of Earth EnvironmentChinese Academy of Sciences Shaanxi key laboratory of Accelerator Mass Spectrometry Technology and Application Xi'an AMS Center Xi'an Jiaotong University A. E. Lalonde AMS laboratory University of Ottawa 150 Louis Pasteur

To meet the measurement demands on small-mass radiocarbon （carbon content at 10.6 g level） which are becoming increasingly significant, Xi＇an-AMS has made improvements to the existing method of sample loading and has upgraded the Cs sputter ion source from the original SO-110 model. In order to study the feasibility of small-mass samples in Xi＇an-AMS and evaluate the radiocarbon sample preparation ability using existing routine systems of H2/Fe and Zn/Fe, the small-mass samples prepared by four different methods are tested. They are the mass division method, mass dilution method, H2/Fe reduction method and Zn/Fe reduction method. The results show that carbon mass above 25 μg can be prepared using the existing Zn/Fe system, but no less than 100 μg is required using the existing H2/Fe system, which can be improved. This indicates Xi＇an-AMS are now able to analyze small-mass radiocarbon samples.

关键词： AMS small-mass radiocarbon sample ion source

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