Trends in UK extreme sea-levels: a spatial approach     

Mark J. Dixon  Jonathan A. Tawn 《Geophysical Journal International》1992,111(3):607-616

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天山中段及祁连山东段小冰期以来的冰川及环境   总被引：22，自引：0，他引：22  

王宗太 《地理学报》1991,46(2):160-168

本文通过考察、航片判读、及AAR法测算了冰川变化,用地衣、文史资料、及树轮年表进行了小冰期的测年,使用实测资料分析、冰岩芯及树轮资料等估算了小冰期的气温与降水、并进而计算了地表径流的变化。在全部讨论中,还引用了一些试验性的方法和公式。  相似文献   

Snow and climate trends and their impact on seasonal runoff and hydrological drought types in selected mountain catchments in Central Europe     

Andrea Blahušiaková  Milada Matoušková  Michal Jenicek  Ondřej Ledvinka  Zdeněk Kliment  Jana Podolinská 《水文科学杂志》2020,65(12):2083-2096

ABSTRACT

This study investigates changes in seasonal runoff and low flows related to changes in snow and climate variables in mountainous catchments in Central Europe. The period 1966–2012 was used to assess trends in climate and streamflow characteristics using a modified Mann–Kendall test. Droughts were classified into nine classes according to key snow and climate drivers. The results showed an increase in air temperature, decrease in snowfall fraction and snow depth, and changes in precipitation. This resulted in increased winter runoff and decreased late spring runoff due to earlier snowmelt, especially at elevations from 1000 to 1500 m a.s.l. Most of the hydrological droughts were connected to either low air temperatures and precipitation during winter or high winter air temperatures which caused below-average snow storages. Our findings show that, besides precipitation and air temperature, snow plays an important role in summer streamflow and drought occurrence in selected mountainous catchments.  相似文献   

Long-term measurements of surface ozone in the German Democratic Republic     

Uwe Feister  Wolfgang Warmbt 《Journal of Atmospheric Chemistry》1987,5(1):1-21

The ozone concentration near the earth's surface has been measured at some stations in the GDR for more than 30 yr using the wet chemical method. Even at rural stations the ozone data show a significant linear increase by about 1–3% yr^–1. The ozone increase being stronger in summer than in winter is assumed to be due to photochemical ozone production from increasing anthropogenic emissions of trace gases that are transported over long distances. A weaker ozone increase by only about 0.2% per year was observed in the free troposphere (5.5 km) from balloon-soundings at Lindenberg within the period 1975–1984. If the ozone trends continue, the ozone concentration near the surface and its seasonal amplitude will have doubled around the turn of the century as compared to the mid-fifties.  相似文献   

Monitoring of the integrated column of hydrogen fluoride above the Jungfraujoch Station since 1977 — the HF/HCl column ratio     

R. Zander  G. Roland  L. Delbouille  A. Sauval  C. B. Farmer  R. H. Norton 《Journal of Atmospheric Chemistry》1987,5(4):385-394

The amount of hydrogen fluoride (HF) above the International Scientific Station of the Jungfraujoch (Switzerland) has been monitored during the last 8 years. The results deduced spectro-scopically from solar IR absorption measurements near 2.48 m indicate a cumulative trend equivalent to (8.5±1)% increase per year, as well as short-term variability which appears to be strongly correlated with meridional circulation patterns during the February–April months. Based on intensified measurements made over the last three years, it is found that the integrated content of HF undergoes a seasonal change with a minimum occurring in the fall. The HF/HCl ratio derived from simultaneous HF and HCl measurements was found equal to 0.15 during the period 1977–79, and 0.24 for the 1983–85 timespan.  相似文献   

吉林省太古宙TTG岩石的两种演化趋势     

孙德有  林强 《吉林地质》1997,16(4):61-69

吉林省太古宙ＴＴＧ岩石形成于２．７～２．８Ｇａ，其母岩浆来自于下地壳角闪质岩石的部分熔融。母岩浆通过结晶分异作用形成了英云闪长质片麻岩类和花岗闪长质片麻岩类两大类岩石，早期的英云闪长质片麻岩类构成奥长花岗岩演化趋势，晚期的花岗闪长质片麻岩类则构成钙碱性演化趋势。研究表明这两种演化趋势的形成与岩浆结晶分离矿物相的种类及其比例有关。  相似文献   

The Role of Ozone Depletion in the Lack of Cooling in the Antarctic Upper Stratosphere during Austral Winter     

Xuan MA  Lei WANG 《大气科学进展》2023,40(4):619-633

Temperature trends in the upper stratosphere are investigated using satellite measurements from Stratospheric Sounding Unit(SSU) outputs and simulations from chemistry–climate models(CCMs) and the Coupled Model Intercomparison Project Phase 6(CMIP6). Observational evidence shows a lack of cooling in the Antarctic, in contrast to strong cooling at other latitudes, during austral winter over 1979–97. Analysis of CCM simulations for a longer period of1961–97 also shows a significant contrast in the...  相似文献   

Historic and Future Perspectives of Storm and Cyclone     

Gang FU  Pengyuan LI  Lijia CHEN  Yongmao PENG  Jing NI 《大气科学进展》2023,40(3):447-463

In weather sciences, the two specific terms “storm” and “cyclone” frequently appear in literature and usually refer to the violent nature of a number of weather systems characterized by central low pressure, strong winds, large precipitation amounts in the form of rain, freezing rain, or snow, as well as thunder and lightning. But what is the connection between these two specific terms? In this paper, the historic evolutions of the terms “storm” and “cyclone” are reviewed from the perspective of...  相似文献   

广西崇左三合大洞新发现的巨猿牙齿化石及其演化意义          下载免费PDF全文

赵凌霞  金昌柱  秦大公  潘文石 《第四纪研究》2008,28(6):1138-1144

文章报告了在广西崇左生态公园三合大洞中新发现的巨猿牙齿化石,这些新化石材料为研究巨猿演化及华南地区更新世动物群时代演化及环境变迁有着重要意义。三合大洞共出土巨猿牙齿56枚,除上犬齿,其他上、下颌牙齿种类齐全;从牙齿发育及磨损情况判断,这些材料代表了婴幼年、青少年、青壮年、中年及老年各年龄阶段的至少5个个体。测量了牙齿大小,并与其他的巨猿化石点的材料进行对比,认为三合大洞的巨猿牙齿与武鸣、巴马的巨猿有可比性。在此基础上,结合动物群组合特征及时代意义,探讨巨猿的牙齿大小时代演化趋势,同时提出存在的问题。  相似文献   

云南气候舒适度分布和变化特征及未来变化趋势预估     

周建琴  黄玮  朱勇  李蒙  周波涛 《气候变化研究进展》2018,14(2):144-154

文章使用云南1961—2015年观测气象资料和RegCM4区域气候模式模拟的RCP4.5和RCP8.5情景下2016—2099年气候变化预估资料,计算了云南逐日气候舒适度指数,采用线性趋势和通径分析等方法分析了云南近55年气候舒适度的时空演变特征和变化成因,最后对未来变化趋势作了预估。结果显示：(1)云南观测资料多年平均值舒适日数最多,占全年的55%,南多北少,夏季最多;寒冷日数次多,占全年的23%,北多南少,冬季最多;冷日数比寒冷日数稍少,占全年的20%;热日数仅占全年的1%,闷热日数多年平均值为零。(2) 1961—2015年寒冷(舒适)日数年际和空间变化都呈明显的减少(增加)趋势,冷和热日数没有明显的变化趋势,闷热日数没有变化。(3)气温是云南气候舒适度各等级日数变化的主要因素,其次是风速,相对湿度只在温度高的情况下影响明显。(4) RCP4.5和RCP8.5两种情景下,2016—2099年云南寒冷(舒适)日数年际和空间变化都是减少(增加)的趋势;冷日数年变化是减少的趋势,空间变化为西北部增加;热日数只在RCP8.5情景下增加明显,主要是南部地区增加。  相似文献