湖沼学

湖泊学P5322005043068粒度和元素证据指示的居延海1.5KaBP来环境演化=EvolutionandclimatechangesoftheJuyanLakerevealedfromgrainsizeandgeochemistryelementsince1500aBP/靳鹤龄,肖洪浪…∥冰川冻土.—2005,27(2).—233～240东居延海湖相沉积的粒度和元素资料研究结果表明:明清以前湖泊的变化主要受气候变化的影响,温暖时期,气候偏湿,入湖水量增多,湖泊面积扩大,流域化学风化作用增强;寒冷时期,气候偏干,入湖水量减小,湖泊萎缩,流域化学风化作用减弱.明清之后特别是近40a来,由于黑河上中游地区大规模的土地开发及水资源利用,入湖水量…     

采用高山松最大密度重建川西高原近百年夏季气温

川西高原高山松树轮宽度及最大密度分析结果表明,最大密度年表和宽度年表中可提取的气候信息是不同的,在温暖、水分条件适中的地区,采用树木密度指标分析气候要素的变化是有效的途径。树轮宽度主要受5月降水影响,和西南季风活动有关;而最大密度主要指示了夏季(6￣9月)温度。利用转换函数重建了川西高原近百年来夏季(6￣9月)温度,重建序列的方差解释量为51%,(F=52.099,p<0.0001)。重建序列显示川西高原,30年代之前为偏冷期,30年代到60年代为偏暖期,与四川地区近百年的冷暖时期比较一致。与平原地区的成都相比,高原的升温转折点提前3年,表明高原地区对气温变化的响应更为敏感,川西高原地区可能是四川省气候变化的先兆地区。1983年以后川西高原地区夏季温度呈明显的上升趋势,20世纪90年代夏季温度的滑动平均为近百年的最大值,但在90年代初期仍处于均值线以下,表现为凉夏;90年代后半期表现为夏旱。     

北极地区20世纪温度变化趋势的不确定性

北极作为地球的冷源之一,对于地球气候系统起着重要的调节作用.本研究通过分析和总结北极地区器测数据和模拟集成结果,以及最近2 000 a来的温度记录,得出如下结果：1）格陵兰冰盖表层大气温度记录显示,20世纪存在1923—1965年和1994年—至今2个相对温暖时段,且前者更为温暖,温度变化幅度远大于北半球的平均温度.2）北极地区20世纪温度上升是客观存在的,其夏季温度和年平均温度呈现一致变化,未发现明显的温度异常信号.3）定量重建的古气候记录显示了北极地区20世纪升温的特征,但不同记录揭示的升温幅度存在差异.与器测结果不同,多条重建记录未能揭示自1994年至今的升温阶段,反映了古气候载体对气候响应的复杂性,揭示出北极地区未来气候变化趋势存在不确定性.在全球变化备受关注的背景下,北极地区对气候变化研究的重要性日益显现,在做出明确结论之前,需要进一步加大研究力度.     

过去2000年亚洲气候变化(PAGES-Asia2k)集成研究进展及展望

介绍了国际过去全球变化研究计划(PAGES)过去2000年气候变化研究网络的设立背景、研究目的及亚洲在其中的独特性;总结了过去2000年亚洲气候变化(PAGES-Asia2k)集成研究的主要进展及中国的贡献,分析了当前在亚洲区域开展该项研究的主要问题及难点,并对未来研究进行了展望。亚洲历史悠久,高分辨率的代用资料丰富,是开展过去2000年气候变化研究的理想区域,但目前尚处于起步阶段。已有进展表明:在过去1200年中,亚洲830-1220年相对温暖,1340-1880年明显寒冷,20世纪则快速增暖;但亚洲气候类型多、变化过程复杂、区域差异大。因此,发展气候序列重建的新技术方法,提高重建序列的时、空分辨率、空间覆盖度和重建结果的精度,建立亚洲过去2000年气候代用资料数据库,集成重建过去2000年区域温度变化序列及干湿变化空间型,进而开展区域气候变化驱动机制与气候变化影响及适应研究,是该计划下一步的研究重点。     

中晚全新世湘西莲花洞石笋灰度变化特征 及其古气候意义

以湖南湘西莲花洞LH2石笋为研究对象,在高精度铀系定年的基础上,构建了湘西地区中晚全新世文石石笋灰度序列。中晚全新世,LH2石笋灰度值与δ18O值呈负相关同步变化,与旋回沉积速率呈正相关关系。LH2石笋的剖面灰度与文石的结晶形态有关,受降雨量和温度的控制。LH2石笋灰度显示,中晚全新世（8.6—0.03 ka B.P.）湘西地区气候变化可以划分为3个阶段：8.6—5.7 ka B.P.期间,夏季风强盛,气候暖湿,灰度值整体偏高;5.7—2.8 ka B.P.期间,灰度值逐渐降低,指示夏季风持续减弱,气候从暖湿向冷干过渡;2.8—0.03 ka B.P.期间,灰度值整体偏低,且存在较大幅度的波动,表明该时段气候整体偏冷干,但其间存在明显的温湿波动。在轨道尺度上,LH2石笋灰度值主要受北半球夏季太阳辐射量和热带辐合带（ITCZ）位置的控制。在百年尺度上LH2石笋灰度值的突变可能与北大西洋冰筏事件存在关联;年代际尺度上,LH2石笋灰度的变化受太阳活动和太平洋年代际涛动（PDO）的调控。在年际尺度上LH2石笋灰度的波动可能受厄尔尼诺—南方涛动（ENSO）活动驱动。     

大气CO_2变化与气候

在地质历史时期,地球的气候不断在变化,全球大气CO2浓度也在变化,二者之间是否存在一种响应—反馈作用,目前存在争议较大.本研究从地质时间尺度、千年以来和现代气候变化3个角度进行介绍,认为全球气候变化是多重时间尺度变化规律的叠加,从长时间尺度来看,全球平均温度和大气CO2水平均表现出整体降低的趋势.地质历史时期存在多次大气CO2浓度升高的时期,有时甚至可达现在大气CO2水平的十几倍.气候变化与大气CO2的关系非常复杂,高CO2时期并不全部对应于高温时期.千年以来的气候变化在全球各大洲均有温暖时期的出现,并且很多地方的重建结果表明中世纪暖期的全球平均温度要比现代的全球平均温度还高.但这一区间的温度变化和大气CO2水平在1850年之前没有明显的相关性.近百年的气候观测资料表明全球平均温度上升了0.74℃,但对于这种上升的理解目前还存在较大争议.是否确实是由于人类活动（主要是工业革命以来）导致了全球CO2水平增高,进而导致全球变暖,需要更多的证据来验证.     

古丝绸之路沿线地区千年冷暖变化的若干特征

依据近期发表的古丝绸之路沿线若干地区(点)的温度重建序列,结合干湿变化等代用记录,分析了过去千年古丝绸之路沿线温度变化的基本特征,以及这些地区(点)在“中世纪气候异常期”(MCA,约950-1250年)和“小冰期”(LIA,约1450-1850年)的干湿特征异同。主要结论为：①过去2000年古丝绸之路的温度变化经历了1-3世纪温暖、4-7世纪前期寒冷、7世纪后期-11世纪初温暖、11世纪中期-12世纪初偏冷、12世纪中期-13世纪中期温暖、13世纪末-19世纪中期寒冷和20世纪快速增暖的百年际波动过程;但不同区域间的年代至百年尺度变化位相不完全同步,波动幅度也存在差异。②各地干湿特征在MCA和LIA也存在一定差异：中国的关中平原及河西走廊在MCA间的干湿变率较LIA大;中亚干旱区MCA期间气候偏干,LIA期间偏湿;欧洲中北部以及斯堪的纳维亚半岛南部等地在MCA间气候较LIA偏干,且中部地区LIA间的干湿变率较MCA大;芬兰和斯堪的纳维亚半岛北部以及俄罗斯等地MCA间的气候较LIA更湿润。     

泾河流域气候变化及其与ENSO的关系

ENSO(厄尔尼诺-南方涛动)常引起大气环流的改变并导致气候异常,探讨区域气候变化与ENSO的关系有助于理解区域水文等各方面的变化.通过Mann-Kendall、相关性检验和小波分析等方法.研究了1960-2005年泾河流域气候变化及其与ENSO的关系.结果表明,1960-2005年,泾河流域气候趋向暖干,且这种趋势在90年代以来愈加显著.气候变化与ENSO有显著的关系.降水对ENSO的响应程度强于温度;降水可能受南方涛动的影响比较大,而温度可能受海表温度的影响较多;ENSO暖事件对泾河流域气候变化的影响可能大于冷事件.     

基于历史文献的华南地区气候变化研究进展

总结和分析了利用历史文献代用资料重建具有代表性的华南气候序列（包括温度变化和降水/干湿变化序列）的状况,认为华南地区历史时期气候变化研究虽已取得丰硕成果,但存在时间分辨率较低、空间范围宽泛、数据的统一性和可靠性较差,以及缺乏气候变化的相关机制和气候变化周期研究等方面的问题,指出应进一步挖掘华南地区高分辨率气候代用资料（历史文献）,提升气候变化研究的时间分辨率和空间覆盖度、加强重建序列的可靠性、增加其周期性和趋势性分析等是解决该地区气候变化研究问题的有效途径。     

新疆伊犁地区近250年冷暖变化特征分析

用树木年轮年表可重建过去的气候，扩展对气候变化的全面估计，本文利用伊犁地区２２个树轮年表，重建了该地区２５０年平均温度序列，并对周期冷暖变化特征进行了分析，对未来趋作了预测。     

Temperature variations evidenced by records on the latest spring snowing dates in Hangzhou of eastern China during 1131–1270AD

We collected and verified documentary records of the latest spring snowing dates(LSSD) in Hangzhou during Southern Song Dynasty. Furtherly, the statistical correlation between this proxy and February–April mean temperature in Hangzhou was examined, and samples later than the perennial mean of the LSSD during Southern Song Dynasty were transformed into the decadal mean of LSSD by means of Boltzmann function. General characteristics of this reconstructed LSSD series with a 10-year temporal resolution was analyzed, and it was also compared with other documentary evidences and reconstructed climate series in China for the period 1131–1270. The results and discussion suggested that:(1) Records of the LSSD in Hangzhou during Southern Song Dynasty did not refer to ice pellets and graupels, which had an explicit climate significance(–0.34℃/10 d, R2=0.37, p0.001). However, when this proxy is used to reconstruct temperature changes, all dates should be converted into proleptic Gregorian style and meet the same criterion of "true Qi" as the Chinese traditional calendar after 1929.(2) The decadal mean of LSSD can be effectively estimated by using the forefront of LSSD in the decade on the basis of Boltzmann function, whose extrapolation has a lesser uncertainty than those on the basis of linear models or polynomial models.(3) The spring climate in Hangzhou during 1131–1270 was almost as warm as the period 1951–1980. At the centennial scale, this period can be divided into two phases: the cold 1131–1170 and the warm 1171–1270. In the latter, 1181–1200 and 1221–1240 were two cold intervals at the multi-decadal scale.(4) The reconstructed LSSD series was consistent well with other documentary evidences and reconstructed climate series in China for 1131–1270, which may reflect the influence on the climate over most regions of China imposed by the Pacific Decadal Oscillation(PDO).     

中国中世纪暖期气候研究综述

中世纪暖期是2000年来全球最重要的气候事件之一,关于中世纪暖期的研究,主要是通过各种代用资料重建气候序列。从目前的研究来看,能敏感响应环境变化的高分辨率的信息载体主要有冰芯、树轮、历史文献、湖泊沉积及石笋等。随着代用资料的开发,对于中世纪暖期的研究已经取得了丰硕的成果,但在中世纪暖期是否具有全球性,不同区域的起讫时间、增温幅度、内部波动以及成因机制等问题上还存在一定争议。主要原因是受重建资料敏感性与地域性限制,加上不同代用指标对气候变化敏感性的差异以及不同代用资料的方法、气候与环境意义等存在差异,定年存在误差。在中国,从对重建资料的整理分析来看,对于"中国是否存在中世纪暖期"这个问题,各研究者们没有达成一致的看法;对于中国中世纪暖期冷暖变化的研究,由于区域差异,东部重建资料以历史文献为主,而西部关于历史气候环境的相关记载很少,所以重建资料以冰芯、湖芯、树轮等为主。大多数的研究结果认为,西部的冷暖变化与东部有着明显的差异,其中最主要的是东部在900~1300 A. D.存在明显的温暖期,而西部则暖期不如东部明显。今后为了更加全面深入的了解中世纪暖期气候特征,应加强各种代用指标高分辨率序列的积累和定量化研究、各种代用指标和重建序列的综合集成研究及其与古气候模拟结果的比较研究,以期从动力学角度加深理解中世纪暖期的区域响应差异。     

1736年以来西安气候变化与农业收成的相关分析

基于清代雨雪与农业收成等档案记载及现代气象观测记录,根据西安冬季降雪与平均气温之间的统计关系、降水入渗与水量平衡模型,分别重建了西安1736~2000年冬季平均气温与4季降水序列,并分析了该地区气候变化特征及其对1736~2000年农业收成的影响。主要结论如下：(1) 西安的冷暖变化存在明显的百年际波动：其中18世纪相对温暖,19世纪寒冷,20世纪又转为温暖,且增暖趋势极为明显。(2) 西安的降水变化存在明显的年代际波动。自1736年以来,共经历了6个多雨期与7个少雨期,其中多雨期的平均雨量比少雨期多16%。(3) 气候变化对农业收成的影响极为明显。其中夏季降水量与秋收关系显著,而夏收又与前一年秋~当年春季的降水明显相关,且大多数严重歉收年均由降水明显偏少而致。虽然温度的年际变化与收成没有显著的联系,但温度年代际变化,即气候的冷暖阶段变化却与收成的阶段性变化关系密切。     

清代华北地区冬半年温度变化重建与分析

利用清代地方志中的异常初、终霜记载,根据器测时期华北初、终霜的早、晚与温度变化的关系,重建了1646-1910 年华北地区时间分辨率为5 年的冬半年温度距平序列,分析了期间的冷暖变化特征.结果表明：清代华北地区气候以寒冷为主要特征,冬半年温度平均较现代(1951-1980 年)约低0.55℃,最冷5 年(1656-1660 年)较现代约低1.42℃;清代华北地区冬半年气候存在“冷-暖-冷”的世纪波动,两个寒冷时段起讫时间分别为1646-1700 年(平均较现代约低0.77℃)和1781-1910 年(平均较现代约低0.58℃),1701-1780 年虽然相对较暖,但冬半年温度仍较现代略低(平均较现代约低0.36℃);从更高时间分辨率看,清代冷暖时段内同样存在较小的波动,清后期寒冷时段出现了两个“冷谷”.     

合肥地区1736－1991年年冬季平均气温序列的重建

本文根据宫廷档案资料“雨雪分寸”中合肥地区的降雪日数的记载，通过寻找其与年冬季平均温度的相关关系，重建了合肥地区从１７３６－１９９１年共２５６年的年冬季平均气温序列。分析表明，合肥地区的年冬季平均气温１８世纪较高，１９世纪下降，２０世纪又开始上升，至２０世纪４０年代达近２５０多年来气温最高值。另外，还发现了在１９世纪中叶（１８５１－１８７１年）有一个明显的温暖期。     

Recent advances on reconstruction of climate and extreme events in China for the past 2000 years

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 multi-decadal-scale severe drought events. Of these, the most severe were in the 1480s and 1710s. In southwest China, extreme droughts as severe as those seen in Sichuan and Chongqing in 2006 are known to have occurred during historical times.     

利用树木年轮重建阿勒泰地区1572—2014年初夏平均温度

利用阿勒泰地区3个高海拔西伯利亚落叶松(Larix sibirica)采样点的树轮样本,建立树轮宽度区域标准化年表(DKH)。通过相关普查发现,DKH年表与阿勒泰地区7个气象站当年6月平均温度显著相关,相关系数为0.705(P<0.00001),表明6月平均温度是影响树木年轮径向生长的主要气候限制因子。用DKH年表可较好地重建该地区1572-2014年共443 a的初夏平均温度,解释方差达49.6%,经验证表明温度重建序列是可信的。温度变化特征分析表明:重建初夏温度经历了10个偏暖和9个偏冷阶段,其中1605-1622年和1682-1723年分别是最暖和最冷的阶段,1875-1913年和1753-1804年分别是持续时间最长的偏暖和偏冷阶段。存在2.37~2.39 a、2.19 a的显著周期(P<0.05)和73.50 a、14.00 a、7.30 a、2.29 a、2.21 a的较显著周期(P<0.10)。在1684年、1719年前后均出现了由冷转暖的突变。空间相关分析表明文章重建的温度序列对阿勒泰地区温度具有较好的空间代表性。本研究重建的初夏温度序列与阿勒泰西部5-9月平均温度和阿尔泰山南坡温度序列相比较,具有较好的一致性。     

A chrysophyte stomatocyst-based reconstruction of cold-season air temperature from Alpine Lake Silvaplana (AD 1500–2003); methods and concepts for quantitative inferences

Relatively little is known about past cold-season temperature variability in high-Alpine regions because of a lack of natural cold-season temperature proxies as well as under-representation of high-altitude sites in meteorological, early-instrumental and documentary data sources. Recent studies have shown that chrysophyte stomatocysts, or simply cysts (sub-fossil algal remains of Chrysophyceae and Synurophyceae), are among the very few natural proxies that can be used to reconstruct cold-season temperatures. This study presents a quantitative, high-resolution (5-year), cold-season (Oct–May) temperature reconstruction based on sub-fossil chrysophyte stomatocysts in the annually laminated (varved) sediments of high-Alpine Lake Silvaplana, SE Switzerland (1,789 m a.s.l.), since AD 1500. We first explore the method used to translate an ecologically meaningful variable based on a biological proxy into a simple climate variable. A transfer function was applied to reconstruct the ‘date of spring mixing’ from cyst assemblages. Next, statistical regression models were tested to convert the reconstructed ‘dates of spring mixing’ into cold-season surface air temperatures with associated errors. The strengths and weaknesses of this approach are thoroughly tested. One much-debated, basic assumption for reconstructions (‘stationarity’), which states that only the environmental variable of interest has influenced cyst assemblages and the influence of confounding variables is negligible over time, is addressed in detail. Our inferences show that past cold-season air-temperature fluctuations were substantial and larger than those of other temperature reconstructions for Europe and the Alpine region. Interestingly, in this study, recent cold-season temperatures only just exceed those of previous, multi-decadal warm phases since AD 1500. These findings highlight the importance of local studies to assess natural climate variability at high altitudes.     

SUMMER TEMPERATURE VARIABILITY IN CENTRAL SCANDINAVIA DURING THE LAST 3600 YEARS

ABSTRACT. A Scots pine ( Pinus sylvestris L.) tree-ring width chronology from Jämtland, in the central Scandinavian Mountains, built from living and sub-fossil wood, covering the period 1632 BC to AD 2002, with a minor gap during AD 887–907, is presented. This is the first multi-millennial tree-ring chronology from the central parts of Fennoscandia. Pine growth in this tree line environment is mainly limited by summer temperatures, and hence the record can be viewed as a temperature proxy. Using the regional curve standardization (RCS) technique, pine-growth variability on short and long time scales was retained and subsequently summer (June–August) temperatures were reconstructed yielding information on temperature variability during the last 3600 years. Several periods with anomalously warm or cold summers were found: 450–550 BC (warm), AD 300–400 (cold), AD 900–1000 (the Medieval Warm Period, warm) and AD 1550–1900 (Little Ice Age, cold). The coldest period was encountered in the fourth century AD and the warmest period 450 to 550 BC. However, the magnitude of these anomalies is uncertain since the replication of trees in the Jämtland record is low during those periods. The twentieth century warming does not stand out as an anomalous feature in the last 3600 years. Two multi-millennial tree-ring chronologies from Swedish and Finnish Lapland, which have previously been used as summer temperature proxies, agree well with the Jämtland record, indicating that the latter is a good proxy of local, but also regional, summer temperature variability.     

清代东蒙农业开发的消长及其气候变化背景

利用档案史料、建置沿革史研究成果等提取信息,建立历史代用指标序列,对清代（1644～1911）内蒙古东部地区农业开发的时空进程进行描述,结合当地农业气候资源条件（温度、降水）及清代气候变化（温度）探讨其中的气候因素。结果显示：（1）清代东蒙农业开发集中在现代年均≥10℃积温2500℃、降水量400mm以上区域之内;（2...