ENSO anomalies over the Western United States: present and future patterns in regional climate simulations     

Yongxin Zhang  Yun Qian  Valérie Dulière  Eric P. Salathé Jr  L. Ruby Leung 《Climatic change》2012,110(1-2):315-346

Surface temperature, precipitation, specific humidity and wind anomalies associated with the warm and cold phases of ENSO simulated by WRF and HadRM are examined for the present and future decades. WRF is driven by ECHAM5 and CCSM3, respectively, and HadRM is driven by HadCM3. For the current decades, all simulations show some capability in resolving the observed warm-dry and cool-wet teleconnection patterns over the PNW and the Southwest U.S. for warm and cold ENSO. Differences in the regional simulations originate primarily from the respective driving fields. For the future decades, the warm-dry and cool-wet teleconnection patterns in association with ENSO are still represented in ECHAM5-WRF and HadRM. However, there are indications of changes in the ENSO teleconnection patterns for CCSM3-WRF in the future, with wet anomalies dominating in the PNW and the Southwest U.S. for both warm and cold ENSO, in contrast to the canonical patterns of precipitation anomalies. Interaction of anomalous wind flow with local terrain plays a critical role in the generation of anomalous precipitation over the western U.S. Anomalous dry conditions are always associated with anomalous airflow that runs parallel to local mountains and wet conditions with airflow that runs perpendicular to local mountains. Future changes in temperature and precipitation associated with the ENSO events in the regional simulations indicate varying responses depending on the variables examined as well as depending on the phase of ENSO.  相似文献   

巴丹吉林沙漠湖泊与地下水的补给来源及化学组成(英文)   总被引：1，自引：0，他引：1  

邵天杰  赵景波  周旗  董治宝  马延东 《地理学报(英文版)》2012,22(3):479-496

Based on the analysis of ion chemical composition of lake water and shallow groundwater in the Badain Jaran Desert, this paper discussed the characteristics of ion chemical composition, spatial variation of lake water, and possible supply sources of lake water and groundwater in the desert areas. The results show that the pH, salinity, TDS and electrical conductivity of the lake water are greater than those of groundwater. The ion con-tents of water samples are dominated by Na+ and Cl?. Most of the higher salinity lakes are Na (K)-Cl-(SO4) type, and a few of low salinity lakes belong to the Na-(Mg)-(Ca)-Cl-(SO4)-(HCO3) type. Most of the groundwater is Na-(Ca)-(Mg)-Cl-(SO4)-(HCO3) type, attributed to subsaline lake, and only a few present the Na-Cl-SO4 type, flowing under saline lake. The pH, salinity, TDS and electrical conductivity in the southeastern lakes are relatively low, and there are slightly alkaline lakes. The pH, salinity, TDS and electrical conductivity in the northern lakes are much greater than those of the southeastern lakes, and the northern lakes are moderately alkaline and saline ones. In the southeastern part of the Badain Jaran Desert, the ion chemical characteristics of the lake water from south to north show a changing trend of sub-saline →saline→hypersaline. The changing trend of chemical compositions of ions in recent 9 years indicates that most of the ion contents have a shade of reduction in Boritaolegai, Badain, Nuoertu and Huhejilin lakes, which state clearly that the amount of fresh water supply is increasing in the 9-year period. The ion chemical composition of the lake water reveals that the flow direction of lake water is from southeast to northwest in the Badain Jaran Desert. The ion chemical composition, moisture content of sand layer water level height and hierarchical cluster analysis of the lake water and groundwater demonstrate that the lake water is mainly supplied by local rainfall and infiltration of precipitation in Yabulai Mountains and Heishantou Mountain, and the supply from the Qilian Mountains is almost impossible.  相似文献   

杭州市空气负离子变化特征分析     

齐冰  杜荣光  邵碧嘉 《气象与减灾研究》2012,(4):68-71

利用2008—2010年杭州西溪湿地和馒头山空气负离子观测资料,分析了杭州市空气负离子的季、月和日变化特征,以及空气负离子与气象环境因子的相关关系。结果表明,湿地负离子浓度要好于市区;杭州市空气负离子浓度冬季最大,夏季最小;一日中早晨空气负离子浓度最高,15时左右最低;夜间高于白天。空气负离子浓度与温度、日照时数和空气污染物呈负相关,与相对湿度、风速、云量和降雨量呈正相关。  相似文献   

利用重叠加窗方式恢复地面运动     

高亮  杨维辉  孙炜  邵帅 《地震地磁观测与研究》2015,(2):36-40

在频率域,利用地震记录反卷积恢复地面运动,由于FFT运算导致的谱泄漏与系统传递函数对高频与低频的放大效果会导致地面运动恢复失败,本研究采用重叠加窗方式,可避免单一加窗的时域失真,并减小频域谱泄漏。结果表明,恢复地面运动取得了较好效果。  相似文献   

Automatic detection of oceanic eddies in reanalyzed SST images and its application in the East China Sea   总被引：1，自引：0，他引：1  

ChunHua Zhang  HongLin Li  SongTao Liu  LianJun Shao  Zhao Zhao  HongWei Liu 《中国科学:地球科学(英文版)》2015,58(12):2249-2259

Oceanic eddies may cause local sea surface temperature(SST), height, and salinity anomalies in remote sensing(RS) images. Remote sensed SST imagery has proven to be an effective technique in oceanic eddy detection, because of its high temporal and spatial resolution. Various techniques have been used to identify eddies from SST images. However, mainly owing to the strong morphological variation of oceanic eddies, there is arguably no uniquely correct eddy detection method. A scheme of algorithm based on quasi-contour tracing and clustering of eddy detection from SST dataset is presented. The method does not impose fixed restrictions or limitations during the course of "suspected" eddy detection, and any eddy-like structures can be detected as "suspected" eddies. Then, "true" eddies can be identified based on the combination of intensity and spatial/temporal scale criteria. This approach has been applied to detect eddies in the East China Sea by using Operational SST Sea Ice Analysis(OSTIA) dataset. Experiments proved that oceanic eddies ranging in diameter from tens to hundreds of kilometers can be detected. Through investigation of the 2007–2011 OSTIA daily SST dataset from the Kuroshio region in the East China Sea, we found that the most active regions for oceanic eddies are those along the Kuroshio path, northeast of Taiwan Island, the Yangtze Estuary and the Ryukyu Islands. About 86% of the cyclonic eddies and 87% of the anticyclonic eddies have the size of 50–100 km in diameter. Only 25% of the anticyclonic eddy and 26% of the cyclonic eddy have the strength more than 0.4°C in the sea surface layer.  相似文献   

Spatial Variability of Soil Parameters of the van Genuchten Model at a Regional Scale   总被引：1，自引：0，他引：1       下载免费PDF全文

Yunqiang Wang  Ming'an Shao  Xiangwei Han  Zhipeng Liu 《洁净——土壤、空气、水》2015,43(2):271-278

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Measurement of the deformation of sand in a plane strain compression experiment using incremental digital image correlation     

Wang  Pengpeng  Sang  Yong  Shao  Longtan  Guo  Xiaoxia 《Acta Geotechnica》2019,14(2):547-557

Acta Geotechnica - This work presents the results from a series of plane strain compression experiments on medium-density sands. In these experiments, a new type of plane strain experimental...  相似文献   

Effect of plastic deformation on hydraulic fracturing with extended element method     

Zeng  Qingdong  Yao  Jun  Shao  Jianfu 《Acta Geotechnica》2019,14(6):2083-2101

The propagation of hydraulic fracture in elastic rocks has widely been investigated. In the paper, we shall focus on numerical modeling of hydraulic fracturing in a class of porous rocks exhibiting plastic deformation. The plastic strain of porous rocks is described by a non-associated plastic model based on Drucker–Prager criterion. The plastic deformation is coupled with fluid pressure evolution described by the lubrication theory. An extended finite element method is used for modeling the propagation of fracture. The fracture propagation criterion is based on the J-integral. The proposed numerical model is validated by comparisons with numerical and analytical results. The influence of plastic deformation on fracture propagation process is investigated.

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内蒙古索伦山地区哈尔博格托尔TTG岩锆石年代学、岩石地球化学及大地构造意义     

薛建平  刘美玉  李钢柱  赵广明  吴春娇  李成元  刘永新  梁月升  连琛芹 《地学前缘》2018,25(3):230-239

内蒙古索伦山地区是中亚造山带构造演化的关键区域,其中关于古亚洲洋的闭合时限以及西伯利亚板块和华北板块的拼贴时空关系一直存在争议。出露于内蒙古索伦山地区哈尔博格托尔的中酸性侵入岩,其深入研究对探讨古亚洲洋演化具有重要意义。文中对内蒙古索伦山地区哈尔博格托尔TTG岩进行了系统的岩石学、年代学及地球化学研究。获得哈尔博格托尔TTG岩的LA ICP MS锆石U Pb年龄为(266.7±3.7) Ma,表明该侵入岩形成于中二叠世。地球化学主量元素分析表明,索伦山地区哈尔博格托尔TTG岩的岩石系列主要为含钠较高的钙碱性准铝质系列。其稀土元素总量较低,呈现轻稀土元素(LREEs)相对于重稀土元素(HREEs)弱富集的特征,Eu异常不明显;微量元素呈现Rb、Ba、Th、U等大离子亲石元素富集,Nb、Ta、Ti等高场强元素强烈亏损的特征,与典型的岛弧岩浆岩类似。结合索伦山TTG岩体地质特征和区域地质背景,综合年代学和地球化学特征分析,笔者认为索伦山地区哈尔博格托尔TTG岩体形成于岛弧环境,即中二叠世期间古亚洲洋壳向华北板块还存在俯冲作用,因而古亚洲洋至少应在中二叠世以后才闭合。内蒙古索伦山地区哈尔博格托尔TTG岩是洋壳俯冲的岩石学记录,为索伦山缝合带及古亚洲洋构造域演化提供了新的基础地质资料。  相似文献   

内蒙古二连盆地巴彦宝力格煤田下白垩统赛汉塔拉组层序—古地理与聚煤作用^*   总被引：1，自引：0，他引：1  

王帅  邵龙义  孙钦平  张云鹤  史鸣剑  孙斌  鲁静 《古地理学报》2018,20(2):325-336

二连盆地巴彦宝力格煤田蕴藏着丰富的煤炭和煤层气资源。利用钻孔和测井资料对赛汉塔拉组层序格架下的古地理演化特征和聚煤作用进行研究,识别出3种层序界面类型: 区域不整合面、河道下切谷冲刷面和对应整合面,将赛汉塔拉组划分为2个三级层序,厚煤层主要发育于层序Ⅰ湖侵体系域早期和晚期。采用单因素分析多因素综合作图法,恢复了层序格架下的古地理格局,古地理单元为冲积扇、扇三角洲平原和滨浅湖。有利聚煤环境为扇三角洲平原与滨浅湖过渡带、滨浅湖,具有合适的基底沉降速率并且受到较小的陆源碎屑影响。从层序Ⅰ到层序Ⅱ,煤层厚度减小,聚煤作用减弱;多层厚煤层的形成受基底沉降震荡性、周期性的影响,受可容空间增加速率与泥炭堆积速率比值不断变化的控制。层序Ⅰ发育时期,研究区中部为下一步煤炭资源和煤层气勘探的有利区。  相似文献