青海东昆仑尕林格铁多金属矿床辉石闪长岩U-Pb年代学及地球化学特征   总被引：1，自引：0，他引：1  

白宜娜  孙丰月  钱烨  刘洪川  张德明 《世界地质》2016,35(1):17-27

对青海尕林格矿区与成矿有关的辉石闪长岩的地球化学特征研究显示,该辉石闪长岩属于偏铝质、钙碱性系列岩石,明显富集活泼不相容元素Th、U和轻稀土元素,相对亏损高场强元素Nb、Ta、Ti和P,具弱的负Eu异常(δEu介于0.924~0.962)。岩石εHf(t)值为-3.79~-1.70,二阶段模式年龄为TDM2为1 223~1 339 Ma。尕林格闪长岩锆石LA-ICP-MS U-Pb加权平均年龄为228±2 Ma(MSWD=0.32),为晚三叠世。综合前人研究成果,认为在巴颜喀拉地块与东昆仑地块碰撞-后碰撞转换阶段俯冲的阿尼玛卿洋壳板片发生断离,引起地幔物质上涌至古老的下地壳底部,使其发生部分熔融并混入部分幔源物质,形成尕林格辉石闪长岩石。  相似文献   

Matlab稳健回归法在FD-3019γ测井仪校准中的应用   总被引：1，自引：0，他引：1  

何涛 《铀矿地质》2016,(4):242-245

简要介绍了FD-3019γ测井仪的校准方法,即Matlab稳健回归法及其抗差性。通过一个实例对比了Matlab稳健回归法和最小二乘法建立的一元线性回归方程,结果表明Matlab稳健回归法较之最小二乘法更为准确。  相似文献   

荔湾3-1组块浮托安装实船监测与数值模拟   总被引：1，自引：1，他引：0  

吴骁  李欣  杨立军  李俊 《海洋工程》2016,34(4):1-8

目前海洋平台日趋集成化、模块化,重量和体积都逐渐增大,使得适合安装大型组块的浮托安装法得到飞速发展。介绍荔湾3-1大型导管架平台浮托安装中使用的实测技术,对驳船的运动监测和海洋环境监测等测量数据进行分析,分析结果被应用于指导整个浮托安装过程,保证浮托安装符合安全施工标准。对浮托安装载荷转移阶段采用数值计算方法进行作业过程模拟,将计算结果与实测结果进行对比分析,两者具有较好的相似性。  相似文献   

Modulation of tropical cyclogenesis in the western North Pacific by the quasi-biweekly oscillation     

Haikun Zhao  Chunzai Wang  Ryuji Yoshida 《大气科学进展》2016,33(12):1361-1375

The quasi-biweekly oscillation(QBWO) is the second most dominant intraseasonal mode over the western North Pacific(WNP) during boreal summer. In this study, the modulation of WNP tropical cyclogenesis(TCG) by the QBWO and its association with large-scale patterns are investigated. A strong modulation of WNP TCG events by the QBWO is found.More TCG events occur during the QBWO's convectively active phase. Based on the genesis potential index(GPI), we further evaluate the role of environmental factors in affecting WNP TCG. The positive GPI anomalies associated with the QBWO correspond well with TCG counts and locations. A large positive GPI anomaly is spatially correlated with WNP TCG events during a life cycle of the QBWO. The low-level relative vorticity and mid-level relative humidity appear to be two dominant contributors to the QBWO-composited GPI anomalies during the QBWO's active phase, followed by the nonlinear and potential intensity terms. These positive contributions to the GPI anomalies are partly offset by the negative contribution from the vertical wind shear. During the QBWO's inactive phase, the mid-level relative humidity appears to be the largest contributor, while weak contributions are also made by the nonlinear and low-level relative vorticity terms.Meanwhile, these positive contributions are partly cancelled out by the negative contribution from the potential intensity.The contributions of these environmental factors to the GPI anomalies associated with the QBWO are similar in all five flow patterns—the monsoon shear line, monsoon confluence region, monsoon gyre, easterly wave, and Rossby wave energy dispersion associated with a preexisting TC. Further analyses show that the QBWO strongly modulates the synoptic-scale wave trains(SSWs) over the WNP, with larger amplitude SSWs during the QBWO's active phase. This implies a possible enhanced(weakened) relationship between TCG and SSWs during the active(inactive) phase. This study improves our understanding of the modulation of WNP TCG by the QBWO and thus helps with efforts to improve the intraseasonal prediction of WNP TCG.  相似文献   

MODULATION OF MADDEN-JULIAN OSCILLATION ON TIBETAN PLATEAU VORTEX     

赵福虎  李国平  黄楚惠  刘晓冉 《热带气象学报(英文版)》2016,22(1):30-41

This study uses NCEP/NCAR daily reanalysis data, NOAA outgoing long-wave radiation (OLR) data, the real-time multivariate MJO (RMM) index from the Australian Bureau of Meteorology and Tibetan Plateau vortex (TPV) data from the Chengdu Institute of Plateau Meteorology to discuss modulation of the Madden-Julian Oscillation (MJO) on the Tibetan Plateau Vortex (TPV). Wavelet and composite analysis are used. Results show that the MJO plays an important role in the occurrence of the TPV that the number of TPVs generated within an active period of the MJO is three times as much as that during an inactive period. In addition, during the active period, the number of the TPVs generated in phases 1 and 2 is larger than that in phases 3 and 7. After compositing phases 1 and 7 separately, all meteorological elements in phase 1 are apparently conducive to the generation of the TPV, whereas those in phase 7 are somewhat constrained. With its eastward propagation process, the MJO convection centre spreads eastward, and the vertical circulation within the tropical atmosphere changes. Due to the interaction between the mid-latitude and low-latitude atmosphere, changes occur in the baroclinic characteristics of the atmosphere, the available potential energy and eddy available potential energy of the atmosphere, and the circulation structures of the atmosphere over the Tibetan Plateau (TP) and surrounding areas. This results in significantly different water vapour transportation and latent heat distribution. Advantageous and disadvantageous conditions therefore alternate, leading to a significant difference among the numbers of plateau vortex in different phases.  相似文献   

RELATIONSHIP BETWEEN TROPICAL ISO AND TROPICAL CYCLONE ACTIVITY OVER THE SOUTH CHINA SEA     

祝丽娟  王亚非  尹志聪 《热带气象学报(英文版)》2016,22(3):318-329

The relationship between the tropical intra-seasonal oscillation (ISO) and tropical cyclones (TCs) activities over the South China Sea (SCS) is investigated by utilizing the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) global reanalysis data and tropical cyclone best-track data from 1949 to 2009. The main conclusions are: (1) A new ISO index is designed to describe the tropical ISO activity over the SCS, which can simply express ISO for SCS. After examining the applicability of the index constructed by the Climate Prediction Center (CPC), we find that the convection spatial scale reflected by this index is too large to characterize the small-scale SCS and fails to divide the TCs activities over the SCS into active and inactive categories. Consequently, the CPC index can’t replace the function of the new ISO index; (2) The eastward spread process of tropical ISO is divided into eight phases using the new ISO index, the phase variation of which corresponds well with the TCs activities over the SCS. TCs generation and landing are significantly reduced during inactive period (phase 4-6) relative to that during active period (phase 7-3); (3) The composite analyses indicate distinct TCs activities over the SCS, which is consistent with the concomitant propagation of the ISO convective activity. During ISO active period, the weather situations are favorable for TCs development over the SCS, e.g., strong convection, cyclonic shear and weak subtropical high, and vice versa; (4) The condensation heating centers, strong convection and water vapor flux divergence are well collocated with each other during ISO active period. In addition, the vertical profile of condensation heat indicates strong ascending motion and middle-level heating over the SCS during active period, and vice versa. Thus, the eastward propagation of tropical ISO is capable to modulate TCs activities by affecting the heating configuration over the SCS.  相似文献   

CLIMATOLOGICAL CHARACTERISTICS OF SPRING PRECIPITATION OVER SOUTHERN CHINA AND ITS INTRASEASONAL OSCILLATION     

潘蔚娟  李春晖  蒋承霖 《热带气象学报(英文版)》2016,22(2):233-242

Based on observations and reanalysis data, the characteristics of the evolution of climatological spring precipitation over Southern China (SPSC) and the associated climatological intraseasonal oscillation (CISO) and atmospheric circulation are studied. Results show that SPSC increases in an oscillatory way. Although the evolution of SPSC is similar in different regions, there are also differences. In different regions of Southern China, the onset dates of the rain season are from the 12th to 24th pentad and the peak dates are after the 20th pentad. CISO is an important component of SPSC, which is not only statistically significant, but also accompanies a dynamically coherent structure. The peak wet/dry phase of each CISO cycle corresponds to a significant rainfall increasing/decreasing period and modulates the evolution of SPSC. The rainfall growth in the second half of March and mid-April is the result of the modulation. The wet/dry phase of CISO is accompanied by low-level convergent (upper-level divergent) and cyclonic (anti-cyclonic) circulation, which favors ascending motion to develop over Southern China.  相似文献   

印太暖池区域海温异常与北极海冰变化的联系          下载免费PDF全文

陈迪高山红  陈锦年 《极地研究》2016,28(1):49-57

采用统计方法,分析了全球海洋表层海温和印太暖池区域海表温度的长期变化特征,探讨了热带印度洋-西太平洋(印太暖池)海表温度异常(SSTA)与北极海冰快速消融之间的可能联系。结果表明,从整体来看,百年来全球SSTA呈现缓慢升高,但期间也存在年际变化的波动,近10年来全球SSTA升高有减缓的趋势,印太暖池区域的SSTA长期变化与全球基本一致。而北极海冰覆盖率自20世纪80年代初由正距平转换为负距平,且以-1.5%/10 a的速度快速减少,每年7—10月的海冰覆盖率减少速度最快,分别为-2.6%/10 a、-2.8%/10 a、-3.0%/10 a和-2.5%/10 a。由相关分析可知,北极海冰覆盖率的快速减少与印太暖池区域SSTA变化存在密切联系,它们之间存在准两年的显著相关。这种联系的重要途径是通过北极涛动(AO)作为桥梁来完成的。采用回归分析,首次建立了夏秋季北极海冰变化与印太暖池区域SSTA之间的预报方程,并对未来两年北极海冰的变化进行了预测试验,2015年和2016年6—10月北极海冰覆盖率异常变化均为-6.16%,仍为快速减少的两年。这一工作对北极海冰变化的深入研究和预测具有一定的推动作用,对全球气候变化的评估提供了理论依据。  相似文献   

热带平流层CO浓度准两年振荡的位相变化特征     

王春晓  田文寿 《大气科学》2017,41(2):275-288

利用2005~2014年10年的卫星微波临边探测仪（MLS）资料分析了热带平流层一氧化碳（CO）体积混合比的年际变率,发现热带平流层CO浓度的准两年振荡（QBO）在30 hPa高度附近存在明显的位相变化特征。大气化学气候模式模拟结果表明,热带平流层CO的准两年振荡信号是化学和动力过程共同作用的结果,而动力作用主要是QBO引起的次级经向环流引起的物质传输。化学和动力过程共同作用导致热带平流层CO浓度的垂直梯度在30 hPa高度处发生反转,进而产生一氧化碳QBO信号的位相变化。此外,化学气候模式模拟结果还表明,与CO有关的化学过程不但可以减弱一氧化碳QBO信号的振幅,还可以在热带30~10 hPa高度范围内造成一氧化碳QBO和纬向风QBO信号之间约3个月的时间差。  相似文献   

2014年夏季青藏高原狮泉河与林芝降水低频振荡及陆—气过程日变化特征     

段丽君  段安民  胡文婷  巩远发 《大气科学》2017,41(4):767-783

根据“第三次青藏高原大气科学试验” 2014年7、8月青藏高原西南部狮泉河站、东南部林芝站的3 m涡动相关系统原始数据和10 Hz湍流资料以及中国气象局台站观测资料、JRA-55（Japanese 55-year Reanalysis）逐日再分析资料、GPCP（Global Precipitation Climatology Project）全球降水逐日观测资料,分别讨论了这两个站在10~20天低频振荡的天气背景下其干、湿位相近地层气象要素的日变化特征以及湍流变化特征。结果表明:两站高低空环流场、水汽通量场、热源的10~20天低频分量在其干、湿位相期间的配置相反。低频地表感热和潜热的不同变化对降水的影响分别在高原西部和东部有不同表现。狮泉河站的低频振荡在纬向上自西向东传播,而林芝站的低频振荡在纬向上自东向西传播,结果表明这两个站分别存在两种不同起源的低频振荡。两站干、湿位相的近地面气象要素以及湍流通量具有明显的日变化特征,通常温度极大值出现在午后14时（北京时,下同）,但狮泉河站干、湿位相的温度极大值均出现在夜间20时;由波文比可知,狮泉河站湿位相全天以潜热为主导,干位相期间,06时之前以潜热为主,06时之后以感热为主;林芝站干、湿位相均为08时之前以感热为主,08时之后以潜热为主。两站湍流平均动能与平均风速正相关,垂直动量表现为向下传输,热量和水汽表现为向上传输。  相似文献