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1环流效应:中国季风区石笋氧同位素短尺度变化的气候意义-古气候记录与现代气候研究的一次对话显示文摘根据最近的研究结果,中国季风区同一洞穴或同一区域的晚全新世石笋氧同位素序列具有较好的重复性,表明中国季风区的石笋氧同位素短尺度(10~100年尺度,后同)变率所具有的信号强于噪音。通过进一步比较分析发现,一些石笋氧同位素记录虽然来自距离上千公里之遥的不同区域,但它们的波动形式在年代际至世纪尺度极其相似,说明它们是一致的大区域信号,但多数石笋氧同位素序列未能校准到本区器测的降水或温度记录上。通过与中国气候学家建立的各类季风指数比较,发现这些具有一致大区信号的中国石笋氧同位素序列与海平面气压差指数或海陆温差指数关系最好。再通过与印度洋-太平洋海域海平面气压差、以及许多海、气环流观测记录对比,发现中国季风区石笋氧同位素序列记录了20世纪后期最强的一次全球海、气环流年代际均值突变,由此初步确认了中国季风区石笋氧同位素短尺度变化的环流意义:当印度洋海水和中东太平洋海水温度偏低时,西太平洋副热带高压偏北东缩而弱,中国季风区内来自印度洋的水汽份额增大,由于这些水汽的输送路程很远,导致中国季风区的雨水氧同位素及石笋氧同位素较轻;而当印度洋海水和中东太平洋海水温度偏高时,西太平洋副热带高压偏南西伸而强,中国季风区内来自印度洋的远源水汽份额减少,而来自西太平洋的水汽份额增大,由于后者输送路程较近,导致中国季风区的雨水氧同位素及石笋氧同位素较重。由此命名瑞利分馏原理所决定、反映印度洋/太平洋海、气环流转变且大区域一致的中国季风区石笋氧同位素10~100年尺度变化为'环流效应'。谭明 2009第四纪研究2009,29,5:107
2近50年西南地区极端干旱气候变化特征显示文摘利用中国气象局整编的1960-2009年西南地区108站逐日气温、降水等资料,计算年、月地表湿润指数,并进行标准化,统计极端干旱发生频率,对年际、年代际、季风期和非季风期的极端干旱变化特征进行分析,得出结论:(1)整体上,四川盆地西南部、横断山区南端、广西南部沿海和贵州北部是近50年来年极端干旱发生频率明显增加的地区;年代际变化上,20世纪60-80年代极端干旱呈逐渐减少趋势,高发区交替出现在东南—西北—东,90年代下降明显,整个地区都转湿,进入21世纪后,极端干旱距平呈现正距平,且增幅较大,区域间差异却显著减小。(2)季风期与非季风期的极端干旱变化有很大差异,季风期极端干旱频率在不断增加,多发生在四川盆地周边海拔较高的山区、广西大部和'帚形山脉'地带,海拔对季风期极端干旱发生频率有一定影响;非季风期缓慢下降,整体偏湿。(3)通过滑动t检验和小波分析发现,季风期西南极端干旱在2003年发生突变,非季风期在1989年突变,年极端干旱发生频率是季风期和非季风期的突变叠加的结果;年极端干旱存在准5年和准12年的周期变化。贺晋云 张明军 王鹏 王圣杰 王兴梅 2011地理学报2011,66,9:159
3Extreme drought changes in Southwest China from 1960 to 2009显示文摘从 1960 ~ 2009 在西南中国基于温度的每日的数据和 108 个气象学的车站的降水,我们计算每月、每年的表面潮湿的索引,以及极端干旱频率。根据数据,极端干旱频率在的时间、空间的特征内部年度,内部十,夏天季风时期和冬季季风时期被分析。结果如下被显示。(1 ) 一般来说,西南的四川盆,南部的 Hengduan 山, Guangxi 的南部的海岸和北贵州是极端干旱频率显著地在过去的 50 年里增加了的区域。至于十的变化,从 1960 年代,到 1980 年代,极端干旱频率介绍了一个减少的趋势,当 1990 年代是最湿的十年,整个区域正在变得湿时。在 2000 年代,极端干旱频率快速升起,但是地区性的差别还原剂。(2 ) 在夏天季风时期期间,干旱频率正在成长的极端,通常在四川盆附近发生在高山,最在云南 Guangxi 和塑造扫帚的山分开。高度在极端干旱频率上有影响,是不同的;在冬季季风时期期间,区域是相对湿的,极端干旱频率正在减少。(3 ) 在夏天季风时期期间,突然的变化在 2003 被观察,而突然的变化在冬季季风时期期间在 1989。年度极端干旱频率变化在夏天季风和冬季季风时期期间是突然的变化的重叠。年度极端干旱频率的离开顺序颤动是 quasi-5 年和 quasi-12 年。ZHANG Mingjun HE Jinyun WANG Baolong WANG Shengjie LI Shanshan LIU Wenli MA Xuening 2013Journal of Geographical Sciences2013,23,1:43
4石笋氧同位素和微量元素记录的陕南地区4200~2000a B.P.高分辨率季风降雨变化显示文摘基于陕南祥龙洞石笋XL2的19个^(230)Th年龄、218个氧同位素分析以及896个Sr/Ca分析数据,高分辨率重建了4200~1972a B.P.期间陕南地区季风降雨变化。重建结果显示陕南地区这一时期季风降雨有显著的127~105a和57a周期,可能分别受控于太阳活动、PDO和/或AMO的变化。重建时段有3次百年尺度的干旱事件,分别发生于2200~2100a B.P.,2900~2700a B.P.和3600~3400a B.P.,其中2900~2700a B.P.干旱事件对应于北大西洋地区2.8ka冷事件。对比研究显示,尽管祥龙洞石笋和董哥洞石笋δ^(18)O记录整体一致,但除了2900~2700a B.P.干旱事件之外,其他两次干旱事件在董哥洞石笋记录中并不明显。而尽管总体上祥龙洞和和尚洞石笋δ^(18)O记录的差异要大,但XL2的3次干旱事件在和尚洞记录都有明显体现。有精确年代控制的祥龙洞、董哥洞及和尚洞石笋氧同位素记录的差异,揭示晚全新世我国季风降雨在十-百年尺度存在区域差异。谭亮成 蔡演军 安芷生 程海 易亮 艾思本 2014第四纪研究2014,34,6:35
5Humid Medieval Warm Period recorded by magnetic characteristics of sediments from Gonghai Lake, Shanxi, North China显示文摘Variations in monsoon strength, moisture or precipitation in eastern China during the MWP reflected by different climatic records have shown apparent discrepancies. Here, detailed environmental magnetic investigations and mineralogical analyses were conducted on lacustrine sediments of Core GH09B1 (2.8 m long) from Gonghai Lake, Shanxi, North China, concerning the monsoon history during the MWP. The results demonstrate that the main magnetic mineral is magnetite. The sediments with relatively high magnetic mineral concentrations were characterized by relatively fine magnetic grain sizes, which were formed in a period of relatively strong pedogenesis and high precipitation. In contrast, the sediments with low magnetic mineral concentrations reflected an opposite process. The variations of magnetic parameters in Gonghai Lake sediments were mainly controlled by the degree of pedogenesis in the lake drainage basin, which further indicated the strength of the Asian summer monsoon. The variations in the and S 300 parameters of the core clearly reveal the Asian summer monsoon history over the last 1200 years in the study area, suggesting generally abundant precipitation and a strong summer monsoon during the Medieval Warm Period (MWP, AD 910–1220), which is supported by pollen evidence. Furthermore, this 3–6-year resolution environmental magnetic record indicates a dry event around AD 980–1050, interrupting the generally humid MWP. The summer monsoon evolution over the last millennium recorded by magnetic parameters in sediments from Gonghai Lake correlates well with historical documentation (North China) and speleothem oxygen isotopes (Wanxiang Cave), as well as precipitation modeling results (extratropical East Asia), which all indicate a generally humid MWP within which centennial-scale moisture variability existed. It is thus demonstrated that environmental magnetic parameters could be used as an effective proxy for monsoon climate variations in high-resolution lacustrine sediments.LIU JianBao CHEN FaHu CHEN JianHui XIA DunSheng XU QingHai WANG ZongLi LI YueCong 2011Chinese Science Bulletin2011,56,23:28
6基于日SPEI的近55 a西南地区极端干旱事件时空演变特征显示文摘利用1960~2014年中国西南地区141个气象台站的逐日气象资料,引入一个新的干旱指数——逐日标准化降水蒸散指数(日SPEI),对极端干旱事件的年代际、年际、季节内变化及持续性特征进行了分析,结果表明:空间上,近55 a西南春季和年极端干旱程度呈一致的减弱趋势,重庆、四川与贵州的交界处及四川西北部极端干旱程度明显缓解,而夏、秋两季极端干旱表现出增强的趋势并有一定的区域性特征。时间上,春季和全年极端干旱频率、强度和持续天数逐渐减少,春季极端干旱的减弱程度较全年明显;夏、秋两季极端干旱频率、强度和持续天数呈增加趋势,夏季极端干旱的加重趋势比秋季明显。从极端干旱事件的持续性来看,20世纪60年代和21世纪初(2000~2014年)西南遭受的极端干旱最严重,持续期达60 d以上的站点分别占到站点总数的60%和73%。贾艳青 张勃 2018地理科学2018,38,3:27
7中全新世7~6ka东亚季风气候的高分辨率石笋记录显示文摘基于神农架青天洞石笋两个230Th年龄、582条纹层计数和183个氧同位素数据,重建了7~6 ka B.P.期间平均3年分辨率的1δ8O变化序列。持续约580年振幅达1.8‰的δ18O在平均值-9.66‰上下波动,指示了东亚季风降水强度的长期演化趋势和高频振荡信息,大致划分为4个百年尺度旋回。青天洞与阿曼石笋δ18O记录的对比表明,东亚季风和印度季风在百年或更短时间尺度上同相位变化,可能反映了两地季风气候受统一的印度洋/太平洋大尺度水汽循环控制。功率谱分析揭示出163、81、16和11年的周期,大致与树轮Δ14C百年至数十年尺度太阳活动变化周期相同。李明霞 汪永进 邱庆伦 2007地理科学2007,27,4:21
8Modern stalagmite oxygen isotopic composition and its implications of climatic change from a high-elevation cave in the eastern Qinghai-Tibet Plateau over the past 50 years显示文摘An oxygen isotope record of a stalagmite from Huanglong Cave in the eastern Qinghai-Tibet Plateau dated with 230Th and 210Pb methods provides variations of the Asian monsoon with an average resolu-tion of 1 year over the past 50 years. This study shows that the δ18O of dripwater in the cave represents the annual mean δ18O of local meteoric precipitation and the stalagmites were deposited in isotopic equilibrium. A comparison of the stalagmite δ18O record with instrumentally meteorological data indi-cates that shifts of the δ18O are largely controlled by the amount effect of meteoric precipitation con-veyed through the southwest monsoon(the Indian monsoon) and less affected by temperature. Therefore,the variations of δ18O record reflect the changes in monsoon precipitation on inter-annual time scales under the influence of the southwest monsoon. Like many other stalagmite δ18O records in the Asian monsoon regions,the δ18O record of the stalagmite from Huanglong Cave also reveals a gradually enriched trend during the past 50 years,i.e. relatively enriched in 18O. This trend may indicate the decline of the Asian monsoon intensity which is consistent with the decrease of monsoon indices. The weakening of the modern Asian monsoon well matched with the temperature changes in strato-sphere,which may illustrate that the weakening of the monsoon mainly results from the lowering of solar radiation.YANG XunLin ZHANG PingZhong CHEN FaHu HUH Chih-an LI HongChun CHENG Hai Kathleen R. JOHNSON LIU JingHua AN ChunLei 2007Chinese Science Bulletin2007,52,9:20
9Circulation background of climate patterns in the past millennium: Uncertainty analysis and re-reconstruction of ENSO-like state显示文摘The question of whether or not global warming has paused since more than ten years ago, namely 'warming hiatus', has attracted the attention of climate science community including the IPCC. Some authors have attributed the 'warming hiatus' to the internal changes in the climate system, i.e., the recombination of ocean-atmosphere circulations. Therefore, it is necessary to propose higher requirements on reconstructing circulation background of climate change for the past millennium. However, the analyses of changes in atmospheric circulation over the last millennium as well as the conclusions of related regional climate patterns are so widely different and contradictory, bringing uncertainties to our understanding of regional even global climate change to a great extent. On the other hand, in the last 10 years the high-precision U/Th-dated stalagmite oxygen isotope ratio(δ^(18)O) sequences provided an accurate chronological frame for the paleoclimate study of the middle and late Pleistocene, in which all authors from China took the Chinese stalagmite δ^(18)O as the summer monsoon index without exception. However, this point of view misleads the climate scientists into thinking that the stalagmite δ^(18)O can be as the proxy of precipitation amount. Nevertheless, it is well known that all of these records have a lot in common in the low frequency trend. However, most sequences cannot be calibrated by instrumental precipitation records, and thus the uncertainty of the climate research framework of China and even of the world has increased. Therefore, it is imperative for climatology to clarify the origin of contradiction and to reduce the uncertainty as early as possible. On the basis of analyzing the significance of stalagmite δ^(18)O in the monsoon regions of China, the author tries to propose a new circulation proxy in this paper: integrating the Chinese stalagmite oxygen isotope sequence to reconstruct the tropical Pacific sea surface temperature gradient, i.e., the large-scale ENSO-like state over the past millennium. Furthermore, the author speculates that it was warm in the modern times and the Medieval Period, but the circulation recombination was different in both periods. And this inference could be supported by the longer record since Last Glacial Maximum. In other words, the attribution analysis of the identical low-frequency trends of Chinese stalagmite δ^(18)O on a large scale shows that the ENSO-like state controls the climate change in the monsoon regions of China at different time scales(from interannual to century or even longer time scales). Wherein the important connection of circulations is the western Pacific subtropical high(WPSH), that is to say, besides the interannual and decadal time scales, the WPSH would possess the circulation mode on longer timescales. For example, we may discuss the change of the WPSH in the whole Holocene epoch, i.e., the half precession period. These discussions could make sense to the study of not only the paleoclimate but also the modern climate.TAN Ming 2016Science China Earth Sciences2016,59,6:16
10陕西定边地区2400cal.aB.P.以来高分辨率的花粉记录及环境变化显示文摘通过对位于黄土/沙漠过渡带定边地区苟池剖面的高分辨率的花粉分析,基于9个 ^(14)C年代数据重建了2400cal.aB.P.以来定边的植被与气候变化,结果表明2400~1 740cal.aB.P.地带性植被为以栎为主的森林草原,气候较温暖湿润;1740~1610cal.aB.P.森林退化,草原发育,气候变干;1610~1240cal.aB.P.乔水成分增加,植被类型为疏林草原,气候较温和湿润;1240~1010cal.aB.P.森林退缩,草原发育,气候变干;1010~690ca1.aB.P.草原进一步发育,气候干旱;690~500cal.aB.P.阔叶树成分增加,气候略温湿;500~190cal.aB.P.草原发育,气候干旱;190~Ocal.aB.P.乔木成分增加,气候变湿。本区花粉记录的植被和气候变化可与区域的世纪初前后(秦汉)暖期、隋唐暖期、中世纪暖期和小冰期等事件对比。蒙红卫 马玉贞 王维 桑艳礼 2009第四纪研究2009,29,5:15
11中国西南五省参考作物蒸散量时空变化分析显示文摘为深入了解中国西南5省ET0演变规律,利用1954—2013年广西、重庆、云南、贵州、四川5个省市119个站点逐日地面气象资料,采用FAO-56推荐的Penman-Monteith公式计算各站点逐日ET0,并使用Mann-Kendall检验、Morlet小波分析和GIS反距离加权插值定量分析ET0时空变化特征。结果表明,1954—2013年西南5省ET0多年平均值为855 mm,波动范围为819~901 mm,年均ET0总体呈下降趋势(倾向率为-1.5 mm/10 a),在春、夏、秋、冬季也均呈下降趋势(倾向率分别为-0.4、-0.7、-0.3、-0.1 mm/10a),分别占全年的26.7%、46.7%、20%、6.6%;西南5省ET0多年平均值分别以26 a、12 a、5 a为第1、第2、第3周期进行“增大-减小”交替变化;1954—2013年,西南5省年均ET0空间分布总体表现为南部大于北部,云贵高原西部和广西地区明显大于四川盆地和云贵高原东部,四川盆地相对最小,川西高原南部和云贵高原东部地区相对最大;西南5省ET0在春、夏、秋、冬季空间分布较高值区分别为云贵高原西部、四川盆地和云贵高原东部、广西地区、云贵高原西部,较低值区分别为四川盆地、云贵高原西部、四川盆地和川西高原东北部、四川盆地和广西地区。张青雯 崔宁博 冯禹 龚道枝 胡笑涛 2016灌溉排水学报2016,35,11:13
12Asian summer monsoon precipitation recorded by stalagmite oxygen isotopic composition in the western Loess Plateau during AD1875―2003 and its linkage with ocean-atmosphere system显示文摘Based on 5 high-precision 230Th dates and 103 stable oxygen isotope ratios (δ18O) obtained from the top 16 mm of a stalagmite collected from Wanxiang Cave,Wudu,Gansu,variation of monsoonal precipita-tion in the modern Asian Monsoon (AM) marginal zone over the past 100 years was reconstructed. Comparison of the speleothem δ18O record with instrumental precipitation data at Wudu in the past 50 years indicates a high parallelism between the two curves,suggesting that the speleothem δ18O is a good proxy for the AM strength and associated precipitation,controlled by 'amount effect' of the pre-cipitation. Variation of the monsoonal precipitation during the past 100 years can be divided into three stages,increasing from AD 1875 to 1900,then decreasing from AD 1901 to 1946,and increasing again thereafter. This variation is quite similar to that of the Drought/Flooding index archived from Chinese historical documents. This speleothem-derived AM record shows a close association with the Pacific Decadal Oscillation (PDO) between AD 1875 and 1977,with higher monsoonal precipitation corre-sponding to cold PDO phase and vice versa at decadal timescale. The monsoonal precipitation varia-tion is out of phase with the PDO after AD 1977,probably resulting from the decadal climate jump in the north Pacific occurring at around AD 1976/77. These results demonstrate a strong linkage between the AM and associated precipitation and the Pacific Ocean via ocean/atmosphere interaction. This rela-tionship will aid to forecast future hydrological cycle for the AM monsoon region,and to improve forecasting potential of climatic model with observation data from cave.LIU JingHua ZHANG PingZhong CHENG Hai CHEN FaHu YANG XunLin ZHANG DeZhong ZHOU Jing JIA JiHong AN ChunLei SANG WenCui Kathleen R. JOHNSON 2008Chinese Science Bulletin2008,53,13:13
13Transmission of oxygen isotope signals of precipitation-soil water-drip water and its implications in Liangfeng Cave of Guizhou,China显示文摘According to systemically monitoring results of oxygen(hydrogen) isotope compositions of precipita-tion,soil waters,soil CO2,cave drip waters and their corresponding speleothems in Liangfeng Cave(LFC) in Guizhou Province,Southwest China,it is found that local precipitation is the main source of soil waters and drip waters,and that the amplitudes of those δ 18O values of three waters(precipitation,soil water and drip water) decrease in turn in the observed year,which are 0‰ to -10‰, -2‰ to -9‰ and -6‰ to -8‰,respectively.Moreover,the δ 18O values for three waters show a roughly simultaneous variation,namely,that those values are lighter in the rainy seasons,weightier in the dry seasons,and that the average δ 18O value of drip waters is about 0.3‰ weightier than that of precipitation,which is modified by surface evaporation processes.We also find that oxygen isotope equilibrium is reached or neared in the formation processes of speleothems in LFC system,and that it is feasible to reconstruct paleotemperature and paleoprecipitation by using δ 18O values of speleothems.However,it should be noted that surface evaporation would affect the oxygen isotope values in the study area.LUO WeiJun WANG ShiJie 2008Chinese Science Bulletin2008,53,21:11
14全新世亚洲季风演变显示文摘亚洲季风是气候系统的重要组成部分,包括东亚季风和印度季风。全新世以来季风变化历史和机制对预测未来季风变化至关重要,是季风数值模拟重要的边界条件。全新世季风变化主要受太阳辐照强度的控制,在太阳辐照变化总趋势的基础上还存在千年—百年尺度的气候突变,与北大西洋冷事件对应。8.2ka和4.2ka存在比较典型的两个弱季风事件,前者特征是高纬寒冷,后者特征是中低纬干旱。近千年以来的中世纪暖期和小冰期发生在人类活动对气候有明显影响之前,对二者变化机制的理解可以加深目前地球气候变化中是自然因素还是人类活动占主导的认识。全新世季风在整体上受太阳辐照强度变化的控制,千年至百年尺度上的气候突变与太阳活动、北大西洋气候振荡、赤道太平洋地区的SST变化等众多因素有关。季风变化尤其是快速气候变化时期的季风研究是季风气候预测的重点也是难点。全新世东亚夏季风与印度季风的变化在整体趋势上是一致的,千年—百年尺度的变化上存在相位差。而东亚冬季风(EAWM)和东亚夏季风(EASM)之间的相位关系还不明确,需要进一步研究。丁大林 李广雪 徐继尚 丁咚 李倩 王丽艳 王昊寅 张洋 2017地学前缘2017,24,4:10
15过去2000年中国气候重建与极端事件研究最新进展(英文)显示文摘China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of Chinese civilization, there are abundant and well-dated documentary records for climate variation over the whole of the country as well as many natural archives(e.g., tree-rings, ice cores, stalagmites, varved lake sediments and corals) that enable high-resolution paleoclimatic reconstruction. In this paper, we review recent advances in the reconstruction of climate and extreme events over the last 2000 years in China. In the last 10 years, many new reconstructions, based on multi-proxies with wide spatial coverage, have been published in China. These reconstructions enable us to understand the characteristics of climate change across the country as well as the uncertainties of regional reconstructions. Synthesized reconstructed temperature results show that warm intervals over the last 2000 years occurred in AD 1–200, AD 551–760, AD 951–1320, and after AD 1921, and also show that cold intervals were in AD 201–350, AD 441–530, AD 781–950, and AD 1321–1920. Extreme cold winters, seen between 1500 and 1900, were more frequent than those after 1950. The intensity of regional heat waves, in the context of recent global warming, may not in fact exceed natural climate variability seen over the last 2000 years. In the eastern monsoonal region of China, decadal, multi-decadal and centennial oscillations are seen in rainfall variability. While the ensemble mean for drought/flood spatial patterns across all cold periods shows a meridional distribution, there is a tri-pole pattern with respect to droughts south of 25°N, floods between 25° and 30°N, and droughts north of 30°N for all warm periods. Data show that extreme drought events were most frequent in the periods AD 301–400, AD 751–800, AD 1051–1150, AD 1501–1550, and AD 1601–1650, while extreme flood events were frequent in the periods AD 101–150, AD 251–300, AD 951–1000, AD 1701–1750, AD 1801–1850, and AD 1901–1950. Between AD 1551–1600, extreme droughts and flood events occurred frequently. In arid northwest China, climate was characterized by dry conditions in AD 1000–1350, wet conditions in AD 1500–1850, and has tended to be wet over recent decades. On the northeastern Qinghai-Tibet Plateau, centennial-scale oscillations in precipitation have occurred over the last 1000 years, interrupted by several multidecadal-scale severe drought events. Of these, the most severe were in the 1480 s and 1710 s. In southwest China, extreme droughts as severe as those seen in Sichuan and Chongqing in 2006 are known to have occurred during historical times.葛全胜 郑景云 郝志新 刘洋 李明启 2016Journal of Geographical Sciences2016,26,7:8
16Temporal and spatial variations in hydrogeochemistry of cave percolation water and their implications for four caves in Guizhou, China显示文摘Soil water and cave drip water from four cave systems in Guizhou, Southwest China, were monitored and sampled monthly from April 2003 to May 2004 to understand spatio-temporal variations in hydro-geochemistry of cave percolation water. The results indicated that among the 5 drip water sites from the Liangfeng Cave (LFC), there were no significant differences among the hydro-geochemical parameters. In the Xiniu Cave (XNC), the drip rates were variable and responded quickly to precipitation events in the 3# (No. 3) drip site with variable water head; both bulk and variation in drip rates were smaller in the 2# with constant water head. However, in the Qixing Cave (QXC) and Jiangjun Cave (JJC), drip rates, concentrations of major ions and saturation index for calcite (SI C ) were smaller, and Mg/Ca ratios in Group I (1#, 2#, 6#, 7# and 8# in the QXC; 2# and 3# in the JJC) were larger than those in Group II (3#, 4#, 5# and 9# in the QXC; 1# and 4# in the JJC). These differences might be the result of different hydrogeological processes above the caves, which are divided into five categories based on hydro-geochemistry data. The formation of some proxies in speleothem, such as Mg/Ca, is likely to be affected by those processes.LUO Weijun WANG Shijie XIE Xingneng ZHOU Yunchao LI Tingyu 2013Chinese Journal Of Geochemistry2013,32,2:7
17贵阳市臭氧的时空分布、气象作用及其与前体物的关系显示文摘利用贵阳市10个环境空气监测站发布的臭氧(O3)及其前体物NO2和CO数据,结合同期的气象观测资料,研究2015年3月1日至2016年2月29日一个自然年O3的时空分布特征、气象作用及其与前体物的关系。结果显示O3日变化显示出'单峰'型分布特征,一般在16:00~17:00点左右达到峰值。在3~10月与次年2月,O3月平均浓度整体较高,而11月、12月和次年1月,O3浓度整体偏低。O3-8h-max浓度与日照时数、日最高气温和风速呈正相关关系,与气压和相对湿度呈反相关关系;贵阳市O3浓度城区相对较低,郊区相对较高,从市中心到郊区污染逐渐增大。大气氧化剂OX的日变化特征呈'单峰'型分布,在春季和夏季的氧化性最强。OX在白天和夜晚的控制因素不同,OX在白天主要受O3控制,在夜间主要受NO2控制。苏志华 韩会庆 李莉 刘静 彭娇婷 2020中山大学学报(自然科学版)2020,59,5:7
18西南地区全新世气候变化概述显示文摘本文较为系统地分析了西南地区石笋、泥炭和湖泊沉积物等自然记录恢复古气候的其本原理,概述了西南地区全新世(近万年来)气候变化研究的主要进展。鉴于西南地区古气候研究的现状,未来应着重加强三个方面的研究:1)加强石笋、泥炭和湖泊沉积物等代用指标记录气候变化的机理研究,建立更为有效的古气候定量/半定量重建方法;2)加强高分辨率、多指标的综合对比研究,揭示重大气候变化事件(如8.2 ka事件4、.2 ka事件和小冰期等)的性质及其对西南地区生态环境的影响;3)加强不同区域气候变化的对比研究,为揭示气候变化驱动力和合理预测西南未来可能出现的气候变化提供科学基础。朱正杰 苏菲 陈敬安 李键 曾艳 王敬富 任世聪 2009地球与环境2009,37,2:6
191470-2014年鄱阳湖流域干湿变化与特征分析显示文摘根据1470年以来鄱阳湖流域各类旱涝史料,按照地形和流域分区重建的原则选取区域内11个代表站点进行干湿序列重建,通过面积加权法集成了1470~2014年鄱阳湖流域逐年干湿变化序列。相关性分析和配对样本T检验结果表明在0.01显著性水平下重建序列通过了可靠性检验。不同干湿等级发生频率的空间分析表明,鄱阳湖流域东北部为涝、偏涝中心分布区;中西部为旱、偏旱中心分布区;鄱阳湖区附近属于旱涝兼有分布类型。利用MK趋势检验、累积距平分析、MK突变检验、功率谱和小波分析等方法,诊断了鄱阳湖流域近545年来干湿变化的趋势性、阶段性、突变点和周期性。结果表明:干湿变化在长期尺度下有上升趋势,但并不显著。干湿序列主要体现为3个下降阶段、两个上升阶段;其中1470~1550年、1630~1730年、1890~2014年等时间段偏干;1550~1630年、1730~1890年等时间段偏湿。1570年、1660年等年份出现了年际干湿突变。功率谱和小波分析结果显示鄱阳湖流域近545年来的干湿变化具有多时间尺度、多周期特征,主要有2~3年、4~8年、8~13年、24~60年和100年以上的周期变化过程。万智巍 贾玉连 章鸣 洪祎君 蒋梅鑫 2018干旱区资源与环境2018,32,6:5
20二龙湾玛珥湖年纹层湖泊沉积物元素的X射线荧光光谱分析显示文摘运用同步辐射X射线荧光光谱分析技术对二龙湾玛珥湖0-485 mm(AD1282-AD1988)区间年纹层沉积物进行了分析,获得了Ti、Mn、Br等6种高分辨率元素含量。并对元素进行了因子分析,提取出控制沉积物化学组成的三个主要因子:早期成岩因子F1、生物成因因子F2和流域侵蚀因子F3。进一步的研究还发现,F2和F3的因子得分分别可以作为气候冷暖和干湿变化的代用指标,从而为古气候古环境重建提供了一条有效的新途径。结合高分辨率纹层年代学结果,初步评价了过去700年来该区域气候及环境演化历史。小冰期在二龙湾地区结束于AD1890年,期间波动较大,但不是表现为持续冷气候,共经历了三次冷波动集中时期。进入AD1890年以来,该区整体上呈现温暖湿润气候,但具体表现为温度逐渐降低、降水量逐渐增加的趋势,直至AD1985年降水量回落,温度转而升高。这是20世纪气候变暖在该区域的反映。游海涛 孙春青 李全林 刘嘉麒 2015核技术2015,38,2:4
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