ENSO cycle and climate anomaly in China

The inter-annual variability of the tropical Pacific Subsurface Ocean Temperature Anomaly (SOTA) and the associated anomalous atmospheric circulation over the Asian North Pacific during the El Ni o-Southern Oscillation (ENSO) were investigated using National Centers for Environmental Prediction/ National Center for Atmospheric Research (NCEP/NCAR) atmospheric reanalysis data and simple ocean data simulation (SODA). The relationship between the ENSO and the climate of China was revealed. The main results indicated the following: 1) there are two ENSO modes acting on the subsurface tropical Pacific. The first mode is related to the mature phase of ENSO, which mainly appears during winter. The second mode is associated with a transition stage of the ENSO developing or decaying, which mainly occurs during summer; 2) during the mature phase of El Ni o, the meridionality of the atmosphere in the mid-high latitude increases, the Aleutian low and high pressure ridge over Lake Baikal strengthens, northerly winds prevail in northern China, and precipitation in northern China decreases significantly. The ridge of the Ural High strengthens during the decaying phase of El Ni o, as atmospheric circulation is sustained during winter, and the northerly wind anomaly appears in northern China during summer. Due to the ascending branch of the Walker circulation over the western Pacific, the western Pacific Subtropical High becomes weaker, and south-southeasterly winds prevail over southern China. As a result, less rainfall occurs over northern China and more rainfall over the Changjiang River basin and the southwestern and eastern region of Inner Mongolia. The flood disaster that occurred south of Changjiang River can be attributed to this. The La Ni a event causes an opposite, but weaker effect; 3) the ENSO cycle can influence climate anomalies within China via zonal and meridional heat transport. This is known as the "atmospheric-bridge", where the energy anomaly within the tropical Pacific transfers to the mid-high latitude in the northern Pacific through Hadley cells and Rossby waves, and to the western Pacific-eastern Indian Ocean through Walker circulation. This research also discusses the special air-sea boundary processes during the ENSO events in the tropical Pacific, and indicates that the influence of the subsurface water of the tropical Pacific on the atmospheric circulation may be realized through the sea surface temperature anomalies of the mixed water, which contact the atmosphere and transfer the anomalous heat and moisture to the atmosphere directly. Moreover, the reason for the heavy flood within the Changjiang River during the summer of 1998 is reviewed in this paper.     

全张量重力数据水平分量噪声滤除方法

为获得更好的噪声滤除方法,本文建立一个球状模型,对全张量重力梯度三个水平分量加入高斯白噪声,并利用FFT和PSD分别对加噪后三个分量(Vxx1,Vxy1,Vyy1)进行频谱分析,根据频谱分析结果分别设计了巴特沃斯低通滤波器和高斯低通滤波器对加噪数据进行滤波,取得了较好效果,并利用复杂模型验证滤波效果。     

柴达木盆地全球末次冰期介形类动物群的演变

晚更新世晚期，柴达木盆地达参1井井深46m以下的沉积物内，水生生物化石有很高的丰度和分异度。介形类为 Cyprideis torosa-Ilyocypris inermis组合，伴生有轮藻类、腹足类、双壳类、植物和鱼类等化石。井深46m~10m，为全球末次冰期盛冰阶（25ka~10ka B.P）沉积，当时气候极端干冷，出现干盐湖地质事件（playa），沉积物由湖相泥岩迅速演变为石盐层，生物化石罕见，几近绝迹。平均40m厚的石盐沉积遍及三湖(台吉乃尔湖、达布逊湖和霍布逊湖)地区，形成了该区天然气赖以保存的最后一道屏障-天然气藏的盖层。井深约10m以上，为全新世暖期或称现代间冰期沉积物，渐变为浅湖相泥岩和粉砂岩夹膏盐沉积。当时处于氧同位素阶段1，湖水盐度逐渐降低，水生生物丰度和分异度再度增高，介形类更替为半咸水-淡水介形类Candona neglecta-Candoniella lactea组合，伴生有丰富的轮藻、腹足类、双壳类等。直到现代，台吉乃尔湖、达布逊湖和霍布逊湖以南由于受昆仑山充足的淡水补给影响，水生生物丰富。三湖以北，远离主要淡水补给区，水体较咸，介形类则为典型的盐湖介形类Eucypris inflata所替代，膏盐沉积比三湖以南明显增多。     

南印度洋副热带偶极子的年代际转变特征

为了增进对南印度洋副热带偶极子(Subtropical Indian Ocean Dipole,SIOD)年代际变化的认识,基于Hadley中心的海表面温度(sea surface temperature,SST)、美国国家环境预报中心的大气再分析数据集Ⅰ(NCEP-NCAR Reanalysis1,NCEP)的大气再分析数据和欧洲中期天气预报中心的海洋再分析数据(Ocean Reanalysis System 4,ORAS4)等,本文分析了1958～2020年SIOD年代际转变的特征和物理机制。结果显示,2000年之前,SIOD存在2～4 a和4～6 a两个年际主周期,但近20 a(2000～2020年)其年际变化周期以1.5～2.0 a为主。与此同时,SIOD的空间特征及其强度在1987年和2004年左右出现了两次显著的年代际转变:1958～1986年(P1)期间强度最大,1987～2003年(P2)期间最弱,2004～2020年(P3)期间居中;P1期间SIOD的最大正SST异常(sea surface temperature anomalies,SSTA)中心位于(46°～80...     

我国矿产资源及矿产品供需形势与建议

为了让国内地质矿产勘查和矿业经济部门及时了解我国矿产资源及矿产品供需形势,介绍了“2006中国矿产资源及矿产品供需形势分析报告会”的内容要点。着重对2006年前三季度我国矿产品供需形势进行了深入分析。根据我国矿产资源的主要特点、矿产品供需形势及存在的问题,提出了若干建议。     

多旋翼无人机航磁系统误差综合补偿研究

多旋翼无人机磁通门航磁系统以其安全、稳定、高效等特点可广泛应用于中大比例尺矿产资源探测领域,但由于磁通门传感器存在三轴不严格正交,灵敏度、零偏不一致造成的转向差,且系统作业中存在固定场干扰、感应干扰和涡流干扰,需要进行流程繁琐的标定和补偿测试.本文根据实测数据分析出航磁系统机电干扰主要来自机载设备高频干扰,针对机电干扰高频特性设计相应低通滤波器进行误差处理,并基于Tolles-Lawson模型建立仪器转向误差和飞行平台机动误差补偿模型,根据两者结构相似的特点,建立综合补偿模型,该模型简单,实用性强,可通过野外一次补偿测试求取补偿参数进而对工区航磁数据进行补偿处理.最后,将综合补偿研究应用到辽宁省兴城市夹山地区航磁数据,综合补偿后的处理有效去除了航磁数据中的条带状干扰异常,并与地面磁测数据异常形态具有良好的一致性,验证了该研究方法有效性和实用性.

     

南中国海东沙海域水合物成藏动力学模拟

基于南中国海东沙海域某地震剖面资料,利用Basin2二维模拟软件,结合研究区有关地温场、热流探测资料和ODP184航次调查的岩心数据,重塑了研究区沉降史、有机质生烃史、古地温场与热史变迁。进而利用“生物成因天然气水合物成藏动力学模拟系统”(Hydrate Dynamics)软件,模拟了水合物聚集的过程与分布范围。模拟结果表明,研究区水合物稳定域较厚(200~250 m),有机质含量适中,生物成因甲烷主要在海底1 km以浅范围内形成。稳定域之下早先埋藏的沉积物中有机质形成的生物成因甲烷在压实流的作用下能够向浅部层位中运移聚集,从而对现在的矿层有所贡献。水合物主要赋存于稳定域底部以上50 m的层位内,富集带中水合物的平均含量约为5%。     

地表覆盖遥感制图耕地要素提取的方法与相关问题探讨

地表覆盖遥感制图是将地表的水体、湿地、人造覆盖、耕地、林灌草地、裸地和冰川等地理要素进行分类提取的一项工作。基于ENVI、eCognition和ArcGIS软件,介绍耕地要素提取的主要流程,同时探讨在影像判读过程中遇到的问题及采取的对策。     

质量管理图表在混凝土质量控制中的应用

为控制混凝土的质量 ,在混凝土的生产过程中 ,测试影响质量的各项工艺参数 ,借助管理图来分析各项数据变化的原因 ,及时采取措施加以控制 ,保证混凝土的质量。