Characteristics of total suspended particulates in the atmosphere of Yulong Snow Mountain,southwestern China

The measurement of black carbon(BC) and organic carbon(OC), dust in total suspended particulates(TSP) was carried out at Yulong Snow Mountain(Mt. Yulong) and Ganhaizi Basin, in the Mt. Yulong region, southwestern China. TSP samples were analyzed using a thermal/optical reflectance carbon analyzer. Results show that average BC and OC concentrations in TSP in the Mt. Yulong region were 1.61±1.15 μg/m3 and 2.96±1.59 μg/m3, respectively. Statistical results demonstrated that there were significant differences in mean BC and OC contents between Ganhaizi Basin and Mt. Yulong at the 0.05 level. Strong correlations between BC and OC indicate their common dominant emission sources and transport processes. Temporal variations of BC, OC, and optical attenuation(ATN) values were consistent with each other in carbonaceous aerosols. The ratios of OC/BC in monsoon season were significantly higher than in non-monsoon in aerosols from Ganhaizi, which is closely related to the formation of secondary organic carbon(SOC) and extensive motor vehicle emissions from tourism activities. The temporal variations of BC, OC and ATN in carbonaceous aerosols in Ganhaizi and Mt. Yulong were totally different, probably due to elevation difference and diverse tourism activity intensity between the two sites. Time-averaged aerosol optical depth(AOD) at the wavelength of 550 nm in Mt. Yulong was higher than that of the inland of the Tibetan Plateau(TP). Source apportionment indicated that intensive exhaust emissions from tourism vehicles were the main local sources of atmospheric pollutant in the Mt. Yulong region. Biomass-burning emissions released from South Asia could penetrate into the inland of the TP under the transport of summer monsoon. Further study is needed to assess light absorption and radiative forcing of carbonaceous aerosols, and modeling research in combination with long-term in-situ observations of light-absorbing particulates(LAPs) in the TP is also urgently needed in future work.     

玉龙雪山冰川稳定同位素分馏冬夏对比

1 Introduction Under the dominance of South Asian monsoon, China’s temperate glaciers are distributed on Hengduan Mountains (southeast of Tibetan Plateau), the central part and southern slope of the Himalaya Mountains as well as the central and eastern p…     

Comparisons of stable isotopic fractionation in winter and summer at Baishui Glacier No. 1, Mt. Yulong, China

Based on the data of δ18O in surface snow, snow pits, meltwater and the glacier-fed river water at Baishui Glacier No.1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier system in winter and summer were compared. The results indicate that the isotopic fractionation degree in summer is greater than that in winter, suggesting that the snow/ice melting is more intense in summer. Moreover, whenever it is in winter or summer, from surface snow to meltwater, and to glacier-fed river water, the gradient of δ18O with altitude gradually increases. This shows that the degree of isotopic fractionation gradually strengthens when surface snow is being converted into meltwater and finally into glacial river water, which suggests that the influence of post-depositional processes on δ18O gradient in the monsoonal temperate glacier region differs spatially.     

西北地区东部季风摆动区大气边界层高度对夏季风活动和季风降水的响应特征

大气边界层高度影响着近地层能量、水分的发展变化,而季风摆动区边界层受夏季风活动和季风降水影响很大,变化特殊,但其边界层高度的响应特征并不清楚。应用西北地区东部5站民勤、榆中、平凉、银川和延安2006—2016年5～9月逐日19时每隔10 m高度高空加密观测资料,以及民勤2006—2016年逐日07时探空规定层和特性层资料,结合地面逐日观测资料,对比计算多种资料找到合适的边界层高度。进一步运用NCEP、EC再分析资料,分析夏季风对季风摆动区的影响,得出边界层高度与夏季风、季风期降水影响的关系。结果表明:基于每隔10 m加密压温湿风探空资料,确定了9点平均位温梯度法作为边界层高度的最佳计算方法,该区边界层高度5～6月较高,7～9月逐渐降低,5～9月平均高度由非季风影响区的2 600 m、季风摆动区的1 800 m逐渐降低到季风影响区的1 500 m以下。边界层高度与地面相对湿度、地温和风场关系密切,湿度越大、风速越大,边界层高度越低,相反,近地面地气温差越大,气温越高,吹西北风时,边界层高度越高。在不受夏季风影响时,边界层高度较高,有夏季影响风时,边界层高度较低。夏季风持续时间越长,边界层...     

North American transect of stable hydrogen and oxygen isotopes in water beetles from a museum collection

Museum collections contain a wealth of insect remains originating from a wide geographic range, which can be used to investigate their utility as a proxy for environmental isotope ratios. Chitinous remains of insects such as beetles (Coleoptera) are chemically stable and their stable isotope composition is strongly related to that of environmental water in the period of cuticle formation. We present a dataset of chitin ??D and ??¹⁸O in two genera of water beetles from a museum collection containing 40 locations for Helophorus (water scavenging beetles) and 48 locations for Hydroporus (predaceous diving beetles) that were selected from latitudes 27?C82°N in North America. Only two genera were used to minimize inter-sample variation caused by species-specific differences in metabolic effects, feeding strategy, habitat, and life cycle. The isotopic composition of water beetle exoskeletons had a strong latitudinal trend (North?CSouth) from ?160 to +65??? for ??D and from 7 to 34??? for ??¹⁸O, paralleling gradients of isotopes in precipitation. Strong relationships were observed between isotopic composition of beetles and modelled July precipitation (0.71?<?R ²?<?0.82, p?<?0.001). The relationship between ??D and ??¹⁸O in the beetle samples had a systematic offset from the global meteoric water line, which was likely caused by metabolic effects during chitin formation. The offset between ??D values in beetles and in modelled precipitation was 33??? larger, on average, for Hydroporus compared with Helophorus, suggesting fractionation of hydrogen isotopes during passage through the food chain. This trophic level effect was not observed for stable oxygen isotopes. Furthermore, the observed deviations between isotopic composition of water beetles and modelled precipitation at collection sites were not constant and indicated local hydrological deviations from modelled precipitation. The largest deviations were observed for sites in the Southern US and the Arctic that are highly evaporative and at sites in the Rocky Mountains and Coastal Mountains that were fed by snow melt. Our results indicated that the isotopic composition of water beetles from a museum collection was systematically related to ??D and ??¹⁸O values of precipitation at the collection site.     

玉龙雪山周边典型河流雨季水化学特征分析

2009 年5~10 月在玉龙雪山周边典型小流域白水河、三束河、哥吉河采集河水样品,水化学分析结果表明,三条河流河水均呈现弱碱性,主要离子组成表现为富集Ca²⁺+Mg²⁺和HCO₃^-+SO₄^2-,且以Ca²⁺和HCO₃^-为主,各类离子存在显著季节变化。离子来源分析表明,玉龙雪山周边小流域河水雨季主要受降水和岩石风化影响,大气降水对河水主要常规离子Na⁺、K⁺、Ca²⁺、Mg²⁺、SO₄^2-的贡献率为分别为23.44%,9.66%,3.10%,17.81%,10.48%。研究区碳酸盐岩的风化产物是河水离子组成的主要控制因素。     

黑河流域中上游地区降水中氢氧同位素与温度关系研究

根据黑河流域中上游地区所取得的降水水样和降水气象资料,分析了该区域降水中氢氧同位素随温度的变化特征,研究了内陆河黑河流域中上游地区降水中氢氧同位素与温度的关系,揭示了降水中氢氧同位素随温度的变化规律。降水中氢氧同位素与温度有很好的正相关关系,且与降雨前后平均气温之间的相关性优于与降雨前和降雨后气温之间的,温度与δ~(18)O之间的相关性优于与δD的。在黑河流域,局地性降水的增加影响降水中氢氧同位素与温度之间的关系,在山前或山前盆地,因局地性降水增加,所以降水中氢氧同位素与温度的关系与山区相比较差。     

中国干旱区与季风区夏季气温变化特征对比

利用1961-2006年西北干旱区139站和东部季风区378站夏季平均气温资料,采用趋势系数、相关性检验等方法,对比分析了两个区域夏季气温的时间和空间变化特征、气温变幅分布,并对产生变化的原因进行了初步探讨。结果表明:受气候变暖大背景的影响,西北干旱区和东部季风区夏季气温变化均为波动式上升趋势,但由于地理位置的差异,受夏季风影响不同,导致西北干旱区(0.24℃/10 a)的升温趋明显高于季风区(0.11℃/10 a),同时明显高于相同纬度区域的季风区(0.15℃/10 a)气温变化趋势。两个区域气温变幅空间变化分布上都存在明显的升温区域和气温变化相对较弱的区域,季风区在黄河中下游以南地区到长江中下游以北的广大地区变化不明显,黄河中下游以北的华北、东北地区有相对较明显的升温趋势;西北干旱区以明显的升温为主,尤其是以青海西部至蒙古高原西部形成的一带状区域为主要明显升温区,其最大升温率达到0.93℃/10 a,变化相对较弱的区域主要位于吐鲁番盆地和塔里木盆地。     

夏季玉龙雪山及丽江盆地水体主要无机离子特征

为探究玉龙雪山地区地-气-水-人之间的相互作用机理,于2005年7月22-28日在云南省丽江市玉龙雪山地区采集不同水体样品,在探讨不同水体水文联系的基础上,对该区域不同水体的无机离子浓度和特征进行了分析。结果表明玉龙雪山地区不同水体无机离子浓度存在较为明显的差距,无机离子浓度较大的是低海拔地区的湖水和地下水,浓度较小的是冰舌融水和融水径流;水体主要无机离子是HCO3-,Ca2＋,Mg2＋,SO42-,Na＋,K＋,Cl-,其中Ca2＋占整个阳离子的53.27%,是最大优势阳离子,阴离子中HCO3-是优势阴离子,占阴离子总量的70.35%左右,优势离子与非优势离子之间浓度差距较大。海拔4270 m以上,受局地岩石岩性的影响无机离子浓度较高;海拔42703180 m,由于新鲜融水未充分溶解基岩的离子和水体本身的沉积作用,离子浓度较低;海拔30462400 m,水岩作用导致水体HCO3-,Mg2＋,Ca2＋,K＋,Na＋浓度较高,季风输送和近源人类活动导致NO3-、SO42-,K＋浓度也较高;相关性分析表明阳离子的来源、存在方式和反应机理的相似性比阴离子强;SO42-对区域水岩反应有较强的加速作用;Mg2＋和Ca2＋同源。     

银川平原降水氢氧稳定同位素时间尺度效应及水汽来源

为揭示银川平原降水稳定同位素的时间尺度效应及水汽来源,采用后向轨迹模型聚类分析法、潜在源贡献分析法(PSCF)和浓度权重轨迹分析法(CWT)解析水汽来源及潜在蒸发源区.结果表明:(1)银川平原降水氢氧稳定同位素组成存在明显的季节性变化,冬半年降水氢氧稳定同位素组成(-38.6‰±51.6‰和-4.5‰±5.2‰)明显偏...     

"5.12"汶川地震次生山地灾害的分布与特点

"5.12"汶川地震的重灾区,主要分布在龙门山高山峡谷区和四川盆地深丘区等地,行政区划上涉及四川省的成都市、绵阳市、德阳市、广元市、阿坝藏族羌族自治州,甘肃省的陇南市,陕西省的汉中市等的山区,面积大于10×104km2.强烈地震除直接造成众多人员伤亡和各种设施被毁外,还在山区引发了大量次生山地灾害,形成灾害叠加,导致灾情更加严重.次生山地灾害主要沿龙门山地震断裂带集中分布和沿河谷两岸山坡分布,具有下列特点:1.类型多样,包括崩塌、滑坡、滚石、堰塞湖、泥石流等;2.数量上以滚石、崩塌、滑坡为主;3.导致了大量人员伤亡;4.堰塞湖主要由地震滑坡、崩塌形成;5.泥石流活动具滞发性,地震直接激发的泥石流仅一处;6.对生态环境破坏极大;7.加剧了防洪形势的严峻性;8.主要沿龙门山断裂带活动;9.活动强弱与地震烈度大小关系密切.     

天山-阿尔泰山拟南芥种群分布与环境的关系

中国的天山及其附近山脉是世界拟南芥及其近缘种的主要分布区之一。在对天山—阿尔泰山的浅山地带拟南芥生存分布多年调查的基础上,选取13个代表性样地及18个相关环境因子,研究了拟南芥种群生存分布与环境因子的关系。结果表明:双向指示种分析(TWINSPAN)将13个拟南芥样地分为4个群落类型:新疆绢蒿、新疆绢蒿—猪毛菜、新疆绢蒿—刺叶锦鸡儿—草原苔草、勿忘草—密穗雀麦—草原苔草4类,各类型对应的环境因子异质性明显。不同群落类型在去势对应分析(DCA)、主成分分析(PCA)和典范对应分析(CCA)各排序图中区分明显,与物种对应较好,与TWINSPAN分类结果基本一致。环境因子的PCA分析发现,坡向、有机质、电导率、pH、土壤含水量和有效钾(均为2个土层)是导致样地间环境异质的主要因素,且这些因子间多呈显著关联。CCA分析发现坡向、有机质、pH、电导率和土壤含水量(均为2个土层)与排序轴相关性最大,分析认为上述环境因子是决定物种分布及多样性格局的主导因子,与环境因子的PCA分析结果基本一致。研究还发现,坡向、土壤含水量(第2层)、有机质(第1层)和pH(两层)是影响各样地十字花科种数变化的主要因素,电导率(第1层)是影响...     

极端干旱区胡杨吸水根系的分布与模拟研究

依据2006年7月在极度干旱区内蒙古额济纳旗的实测资料,对胡杨吸水根系根长密度的分布特征进行了分析和拟合,建立了根长密度垂直方向和水平方向的一维、二维分布函数,以期对胡杨根系吸水及胡杨SPAC系统进一步的研究提供有力的试验依据和理论支持。试验结果表明:在垂直方向,吸水根根量主要集中在0~80 cm的土层内,占吸水根总量的97.60%;在水平方向,0~220 cm范围内根长密度随距离的增加而逐渐增大;220~400 cm范围内根长密度随距离的增加而逐渐减小;在0~20 cm范围内,吸水根系仅占总量的0.47%;在160~220 cm范围内,吸水根系分布最为密集,占总量的18.57%。统一采用指数函数对胡杨吸水根系根长密度分布函数进行了拟合,拟合函数与实测数据的相关系数平方分别为:0.888 4、0.680、0.73和0.685,说明胡杨吸水根系根长密度分布也具有与果树相似的规律,基本符合指数衰减规律。     

中国沿海地区快速城市化过程中的农村发展

The sustainability of regional rural development depends on the integrated status and the coordination between rural resources-environment conditions and rural socioeconomic development. In this paper a diagnostic indicator system is proposed to appraise four representative rural development models such as Mentougou model, Taicang model, Yueqing model and Qionghai model in the eastern coastal region of China from the integrated perspective of population, resources, environment, and development. In conclusion, the formation and evolution of these diverse rural development models are the direct response to the very different characteristics in the environment, market demand, and regional culture. These models are common in that their sustainability depends on the scientific guidance of the regional development functional positioning, strong intra-regional interactions, and self-adaptability to the external conditions.     

Appraisal of typical rural development models during rapid urbanization in the eastern coastal region of China

The sustainability of regional rural development depends on the integrated status and the coordination between rural resources-environment conditions and rural socioeconomic development. In this paper a diagnostic indicator system is proposed to appraise four representative rural development models such as Mentougou model, Taicang model, Yueqing model and Qionghai model in the eastern coastal region of China from the integrated perspective of population, resources, environment, and development. In conclusion, the formation and evolution of these diverse rural development models are the direct response to the very different characteristics in the environment, market demand, and regional culture. These models are common in that their sustainability depends on the scientific guidance of the regional development functional positioning, strong intra-regional interactions, and self-adaptability to the external conditions.     

Carbon stable isotopes ratios of pelagic and littoral communities in Alchichica crater-lake, Mexico

Carbon stable isotope ratios were determined in dominant biotic components of pelagic and littoral systems in Alchichica crater-lake. Results showed that carbon signatures were significantly different between both systems. The pelagic environment was more depleted (−26.15 to −15.14 per mille) than the littoral zone (−21.03 to −17.91 per mille). The potential source end-point in the simplified pelagic community was established to be diatomaceous phytoplankton; its predicted value was −21.7 per mille. There is a clear evidence thatNodularia does not sustain the pelagic food chain. In contrast, the highly diverse littoral community was sustained by epiphytes. No allochthonous sources seemed to influence this food web.¹³C enrichment was observed along the components of both systems with fractionations of 0.8 to 1.4 per mille. The contribution of the seagrassRuppia maritima is probably associated with the detritus pathway. Carbon source partitioning between both systems was not recorded. The δ¹³C in Alchichica crater-lake was more enriched than in other saline lakes and could be attributed to different salinity and CO₂ concentrations among lakes.     

基于氢氧稳定同位素和水化学的青藏高原高寒内陆流域水文过程示踪研究

氢氧稳定同位素和水化学已成为研究水文循环过程的良好示踪剂,两者的结合能很好地揭示流域或者区域(特别是缺少水文观测数据的高寒内陆地区)的水文循环过程.青藏高原地表环境较恶劣,缺乏流域尺度的水文观测资料,不利于对流域尺度水文循环过程的综合理解和认识,成为水资源高效综合利用的瓶颈.为此,本文以青海湖沙柳河流域为研究对象,通过...     

Deep-water renewal in a Scottish fjord: temperature, salinity and oxygen isotopes

The sea lochs (fjords) of north-west Scotland are located in a region of Europe particularly well situated to monitor changes in westerly air streams. The moisture transported in these air streams has a profound effect on regional precipitation, freshwater run-off and, in turn, sea loch circulation. The gentle slope of the regional salinity:δ¹⁸O mixing-line, defined as 0.18 ‰ per salinity unit, suggests that the temperature: δ¹⁸O relationship may be readily resolved in these coastal waters. Deep-water renewal events, both observed and predicted from empirical models, in the bottom-waters of Loch Etive provide an opportunity to assess the temperature, salinity and δ¹⁸O relationship. Predicted changes in δ¹⁸O_calcite as a function of changing salinity (ΔS) and changing temperature (ΔT) during deep-water renewal events suggest that >80% fall above analytical detection limits. The theoretical likelihood of recording such renewal events in the "palaeoclimate" record appears to be promising, but temperature and salinity change during renewal events may have either sign. Scottish fjords, because of the relatively small impact which salinity has on δ¹⁸O_water, may provide useful study sites in palaeoclimate research, particularly where palaeotemperature is the primary record of interest.     

第四纪察尔汗地区石盐沉积中的氯同位素组成

采用基于Ｃｓ２Ｃｌ＋离子的正热电离质谱高精度测定氯同位素方法（在９５％的置信水平时，测定精度为０．０２％），测定了柴达木盆地察尔汗盐湖ＺＫ─８９０４钻孔原生石盐和次生石盐中氯同位素组成．研究表明五万年以来察尔汗地区氯同位素组成δ３７Ｃｌ的变化范围为－１．１５７～－０．３７９‰（ＳＭＯＣ）．根据氯同位素，组成的变化规律并结合ＺＫ─８９０４钻孔中氢氧同位素组成，推断出在此期间察尔汗盐湖至少经历了三次较大规模的淡化，冰后期和增温干旱期的两次湖水淡化对现代盐湖的形成起到了重要的作用，同时也复证了该地区的古气候演化模式。     

Terrain features of the Priolkhonie region

We examine the main terrain features in the Priolkhonie region, the low-mountain marginal stage on the western shores of Middle Baikal, from the mouth of the Buguldeika to the Olkhonskiye Vorota strait.