近半个世纪来气候变暖背景下黄河流域潜在蒸散量的变化(英文)

According to the meteorological observation data of 72 stations from 1960 to 2010 in the Huanghe (Yellow) River Watershed, China, the long-term variations of potential evapotranspiration, calculated in the modified Penman-Monteith model of Food and Agriculture Organization of the United Nations, were presented, as well as the meteorological causes for the decrease of potential evapotranspiration were discussed. Since 1960, temperature has risen significantly and potential evapotranspiration a decreasing trend, which indicated the existence of "Evaporation paradox" in the Huanghe River Watershed. This phenomenon was not consistent spatially or temporally with the increase of temperature, potential evapotranspiration decreased in spring, summer and winter, mainly over most parts of Shanxi and Henan, and some parts of Gansu, Ningxia, Inner Mongolia, and Shaanxi. During the recent half century, the trends of temperature and potential evapotranspiration were negatively correlated at most of the stations, while precipitation and potential evapotranspiration exhibited a contrary trend. Calculated in multiple regressions, the contribution to potential evapotranspiration change of related meteorological factors was discussed, including mean pressure, maximum and minimum temperature, sunshine hours, relative humidity and average wind speed. The decrease of wind speed in the Huanghe River Watershed may be the dominating factor causing potential evapotranspiration decreasing.     

A model test system with a dynamic load device for geotechnical engineering in cold regions

A model test system with a dynamic load device for geotechnical engineering in cold regions is presented. This system consists of a model test tank, a refrigeration device and temperature controller, a dynamic load device, together with sensors and data loggers for detecting stress, deformation, and temperature changes. The system can accommodate soil blocks up to 3 m in length, 2.5 m in width, and 1 m in height. The lowest temperature provided by the refrigeration device is -20 °C. The maximum load provided by the dynamic load device is 100 kN and the vibration frequency of the dynamic load can range from 0.1 to 10 Hz. A number of waveforms, such as sine waves, rectangular waves, triangle waves, and other user-defined waves can be generated by the dynamic load device controller.     

三江平原气温降水变化分析——以建三江垦区为例

气温及降水与人类生产生活密切联系,其变化必然会对生态系统和社会经济等产生重大影响。利用三江平原建三江垦区15个农场气象站1965～2002年气温和降水资料,运用气候趋势系数和一元回归分析法进行气候变化分析。结果表明:近40年来本区气温呈显著上升趋势,平均气温以0.50℃/10a幅度升高,不同季节平均气温均呈上升趋势,且冬季增幅最大,达0.82℃/10a。气温升高存在显著的区域差异,最大的增温中心位于南部边缘,气温倾向率大于0.60℃/10a。降水趋势性变化不显著,但仍呈弱减少趋势,年降水量倾向率为-1.90mm/10a,四季降水量以秋季减少最为显著。在此基础上进行气候突变分析,结果表明气温突变出现在1987年,降水突变出现在1980年和1997年,但降水突变不明显。研究三江平原建三江垦区的气候变化对于保障区域粮食安全具有重要的指导意义。     

珠三角地区地表温度与土地利用类型关系

随着城市化进程的加快,城市气候与环境问题日益显现,尤以城市热岛效应最为突出。通过监督分类方法对TM遥感影像进行了土地利用分类,并运用TM热红外波段线性拟合模型进行近地表气温反演,分析城市热岛的空间分布及地域性差异,以及与土地利用类型的关系。结果表明:珠三角地区近地表气温与土地利用类型紧密相关,城市建设区形成高温中心,是热岛的主要贡献因子,植被和水体则有明显的冷岛效应;研究区热岛具有区域性集中与分散分布的特点,且以区域性热岛为中心向周边扩展;分析热岛强度剖面线发现,由于地形、植被覆盖度等因素影响,研究区热岛强度的南北差异较大,而东西差异较小;热岛分布与土地利用类型分布格局较为一致,但也有分布不一致性的区域,表现为城市热岛向非城市建设用地扩展。     

全球气候变化下秦岭南北气温变化特征

选取秦岭南麓1 000 m划分方案,运用气候倾向率、线性拟合方程、Mann-Kendall非参数检验、小波分析等气候数理统计方法,分析秦岭南北气温变化特征。结果表明:近50 a秦岭南北气候变化具有同步性,增温趋势明显;在气温突变方面,关中地区气温突变(1995年)早于陕南(1998年)。通过近10 a秦岭南北气温时空格局演变分析,认为秦岭地区气温变化符合全球变化规律,其变化是自然因素和人类活动共同作用的结果,在小尺度上人类活动干扰尤为明显(特别体现在快速城市化影响气温上升)。     

库姆塔格沙漠春季近地面风场、温度场特征

 利用中尺度区域预报模式系统对库姆塔格沙漠及其周边地区春季近地层风场与温度场分布特征进行了模拟和分析。结果发现,受青藏高原地形影响,偏北气流向南运行在途经库姆塔格沙漠的过程中发生3个分支:①在沙漠东部气流逐渐转变为西北风吹向甘肃省;②中西部气流以较强的东北风流向塔克拉玛干沙漠;③另一部分气流继续顺势南下流入青海省。沙漠区域温度从北向南逐渐降低,在青海省的边界上出现一个低温带,然后温度又开始增加。     

陇东地区近51 a气温时空变化特征

 基于陇东地区15个气象站点1957—2007年的月平均气温、日平均气温资料,结合GIS空间分析技术和数理统计理论,对其气温变化进行定量化分析,阐述其时空演变特征。结果表明,陇东地区多年平均气温较高的地方在中部地区,西部地区平均气温较低,主要是受地形影响;年均气温总体呈上升趋势,春、冬季的增温趋势最为明显,这与全球气温变化及中国气温变化总体趋势一致;年均气温变化的第一主周期为13 a,四季平均气温变化的第一主周期分别是25 a、25 a、13 a和7 a;年均气温的突然升高开始于20世纪80年代中期,四季平均气温的突然升高分别始于90年代中期、90年代初、80年代末和90年代初。     

Permafrost mapping of Northeast European Russia based on the period of climatic warming 1970-1995

Verdenskrigen som efterhånden i do krigførende land tok alle hjelpemidler og all intelligens i sin tjeneste og innskrenket den frie samferdsel selv for de nøitrale stater, måtte selvfølgelig legge hindringer i veien for forskningsekspedisjoner til Asia. De stoppet velikke helt op. Som vi skal se blev der også under krigen foretatt og begynt undersøkelser av denne art; men først efter krigen utviklet de sig igjen i større stil. Det synes derfor å være naturlig å velge denne verdenskatastrofe som et skille, og jeg vil i det følgende mere utførlig omtale bare de ekspedisjoner og forskninger, som vesentlig er blitt utført efter denne tid.     

Changing Trends of Daily Temperature Extremes with Different Intensities in China

By comparing two sets of quality-controlled daily temperature observation data with and without the inhomogeneity test and adjustment from 654 stations in China during 1956-2004 and 1956-2010, impacts of inhomogeneity on changing trends of four percentile temperature extreme indices, including occurrences of cold days, cold nights, warm days, and warm nights with varying intensities, were discussed. It is found that the inhomogeneity affected the long-term trends averaged over extensive regions limitedly. In order to minimize the inhomogeneity impact, the 83 stations identified with obvious inhomogeneity impacts were removed, and an updated analysis of changing trends of the four temperature extreme indices with varying intensities during 1956-2010 was conducted. The results show that annual occurrences of both cold nights and cold days decreased greatly while those of warm nights and warm days increased significantly during the recent 20 years. The more extreme the event is, the greater the magnitude of changing trends for the temperature extreme index is. An obvious increasing trend was observed in annual occurrences of cold days and cold nights in the recent four years. The magnitude of changing trends of warm extreme indices was greater than that of cold extreme indices, and it was greater in northern China than in southern China. Trends for summer occurrence of cold days were not significant. Decreasing trends of occurrences of both cold nights and cold days were the greatest in December, January, and February (DJF) but the least in June, July, and August (JJA), while increasing trends of warm nights were the greatest in JJA. Cold nights significantly decreased from 1956 to 1990, and then the decreasing trend considerably weakened. The decreasing trend also showed an obvious slowdown in recent years for occurrence of cold days. However, increasing trends of warm nights and warm days both have been accelerated continuously since the recent decades. Further analysis presents that the evolution of the trends for occurrences of the four temperature extreme indices was dominated by the changes in northern China.