Daily rainfall projections from general circulation models with a downscaling nonhomogeneous hidden Markov model (NHMM) for south‐eastern Australia

An ensemble of stochastic daily rainfall projections has been generated for 30 stations across south‐eastern Australia using the downscaling nonhomogeneous hidden Markov model, which was driven by atmospheric predictors from four climate models for three IPCC emissions scenarios (A1B, A2, and B1) and for two periods (2046–2065 and 2081–2100). The results indicate that the annual rainfall is projected to decrease for both periods for all scenarios and climate models, with the exception of a few scenarios of no statistically significant changes. However, there is a seasonal difference: two downscaled GCMs consistently project a decline of summer rainfall, and two an increase. In contrast, all four downscaled GCMs show a decrease of winter rainfall. Because winter rainfall accounts for two‐thirds of the annual rainfall and produces the majority of streamflow for this region, this decrease in winter rainfall would cause additional water availability concerns in the southern Murray–Darling basin, given that water shortage is already a critical problem in the region. In addition, the annual maximum daily rainfall is projected to intensify in the future, particularly by the end of the 21st century; the maximum length of consecutive dry days is projected to increase, and correspondingly, the maximum length of consecutive wet days is projected to decrease. These changes in daily sequencing, combined with fewer events of reduced amount, could lead to drier catchment soil profiles and further reduce runoff potential and, hence, also have streamflow and water availability implications. Copyright © 2012 John Wiley & Sons, Ltd.     

新安含镍基性岩体的岩石学,岩石化学及地球化学初步研究

通过对新安含镍基性岩侵入体的岩石学、岩石化学与地球化学研究,认为它与赤柏松含镍基性岩体是同源、同期、产于不同部位的孪生岩体,一旦有暗色橄榄辉长苏长岩相大量出现,则具找矿远景。     

The glacial topography in the area of the middle-lower reaches of the Yangtze river

The Quaternary glacial landforms, such as cirques, glacial troughs, rockdrumlins and lateral moraines are discovered in the area of the middle-lower reaches of the Yangtze river. The isograms of gravels in the moraines reveal that the a-axes of the gravels are mostly parallel to the trends of the valleys. The inclinations of the a-axes of the gravels are 18°–23°. The tendency of the ab-pianes is varied. The inclinations of ab-planes are 15°–20°. The fine grains in the moraines are of bimodal form in the size-frequency curves. The surface of the quartz grains of the moraines possess typical characteristics of glacial sands. Based on the feature of glacial landforms and the data of analysis of the experiment in the laboratory, authors divide the climatic period of Quaternary in this area into four glacial stages.     

El Nino/Southern oscillation signals in the global tropical ocean

The monthly mean sea surface temperature data of 6 areas are used to study the El Nino/Southern Oscillation signals in the global tropical ocean. These areas are in the 5oN-5oS latitude zone at 1) eastern Pacific (110o-l40oW), 2) western Atlantic (30o-50oW), 3) eastern Atlantic (10oW-10oE), 4) western Indian Ocean (30o-50oE), 5) central Indian Ocean (70o-90oE) and 6) far western Pacific (120o-140oE), and the data cover the 120-month period of December 1968 to November 1978.A power spectrum analysts shows that the characteristic time of the El Nino/Southern Oscillation (about 3-4 years) appears not only in the eastern Pacific but also in other areas of the tropics except for the western Pa-cific, where the spectrum is of white noise. The amplitude of oscillation in the eastern Pacific is about 4 times larger than the others, making the El Nino/Southern Oscillation signal the strongest in this area. According to a cross-spectrum analysis, there is no time lag between the variation in the central Indian Ocean and that in the eastern Pacific. These two areas oscillate simultaneously and comprise the main feature of the El Nino/ Southern Oscillation. Other tropical areas are related with time lags, as shown by correlation and coherence calculations.It should be noted that the sea surface temperature in the eastern Pacific oscillates in phase with that in the Indian Ocean, while the pressure oscillations in these two areas are out of phase with each other, according to the Southern Oscillation definition. It is suggested that the Southern Oscillation cannot be explained simply by the sea surface temperature anomalies.Variations in the far western equatorial Pacific do not have the time scale of the El Nino/Southern Oscilla-tion, perhaps because it is a buffer zone between the monsoon system and the trade wind system.     

福建浦城丘源地区晚太古代变质岩地质特征

浦城丘源地区出露太古代变质岩，其地质特征类似于建宁西部上太古界天井坪组，并取得了２６７８±４１Ｍａ同位素年龄资料。本文系统论述其岩石组合、原岩建造、大地构造环境及同位素地质年龄等特征。     

宝顶石刻区污染地下水对造像岩体的破坏作用

污染地下水渗入大佛湾摩岩造像群，在石刻表面积聚可溶盐，加剧了石刻的侵蚀破坏，其中尤以泥质细粒长石砂岩风化剥落最为严重。研究渗水病害对石刻保护有重要意义。     

辐射日总量的最热坡度解析模式及其全球分布规律

本文给出了南北向坡面最热坡度的解析模式。（１）在北半球（下同），冬半年南坡存在最热坡度，且随纬度升高而增大，接近极夜时趋于９０°。（２）夏半年，存在两个临界纬度当时，南坡有最热坡度；当或时，北坡出现最热坡度。给出了和的解析式，证明分别是全球水平面上日辐射量最大值和最小值所在的纬度，它们仅依赖于赤纬。（３）最热坡度所在坡面获得的日辐射量，冬半年低纬大于高纬；夏半年低纬北坡随纬度递增，南坡时等于处水平面上日辐射量，极昼区内，北坡等于极点水平面的日辐射量。     

塔里木盆地西北缘中奥陶统、下志留统的空间分布特征及其相变的遥感分析

根据塔里木盆地西北缘中奥陶统和下志留统各组岩石的光谱特征分析，选择了ＴＭ３/１（Ｙ）２/３（Ｍ）７/５（Ｃ）减色比值合成影像对研究区岩石地层层序进行划分和对比，划分出Ｏ1₂、Ｏ2₂、Ｏ3₂、Ｓ1₁和Ｓ2₁等５个影像岩石地层单元，它们与研究区的岩性组一致，但其精度高于研究区１:２０万地质图。通过影像岩石地层的对比研究发现，研究区西部皮羌断裂以西在中奥陶世几乎未接受沉积，皮羌断裂以东出现了坎岭组，再往东至研究区东部，中奥陶统沉积较全；早志留世早期研究区西部沉积了海相红层，往研究区东部则相变为海相绿色地层。尤其是通过ＴＭ比值图像的分析，发现前人认为分布很局限，但具有很大生油潜力的印干组在研究区分布范围较广，并推断其沉积中心位于与研究区相邻的塔北隆起和北部坳陷一带。这为塔里木盆地油气评价和勘探提供了新的资料，并表明ＴＭ遥感数据的应用是沉积盆地油气勘探研究中的一种很有潜力技术方法。