The relationship between significant wave height and Indian Ocean Dipole in the equatorial North Indian Ocean     

Chen Fu  Dongxiao Wang  Lei Yang  Yao Luo  Fenghua Zhou  Tilak Priyadarshana  Jinglong Yao 《Ocean Dynamics》2018,68(6):689-699

Based on reanalysis data, we find that the Indian Ocean Dipole (IOD) plays an important role in the variability of wave climate in the equatorial Northern Indian Ocean (NIO). Significant wave height (SWH) in the equatorial NIO, especially over the waters southeast to Sri Lanka, exhibits strong interannual variations. SWH anomalies in the waters southeast to Sri Lanka correlate well with dipole mode index (DMI) during both summer and autumn. Negative SWH anomalies occur over the oceanic area southeast to Sri Lanka during positive IOD events and vary with different types of IOD. During positive prolonged (unseasonable) IOD, the SWH anomalies are the strongest in autumn (summer); while during positive normal IOD, the SWH anomalies are weak in both summer and autumn. Strong easterly wind anomalies over the southeast oceanic area of Sri Lanka during positive IOD events weaken the original equatorial westerly wind stress, which leads to the decrease in wind-sea waves. The longer wave period during positive IOD events further confirms less wind-sea waves. The SWH anomaly pattern during negative IOD events is nearly opposite to that during positive IOD events.  相似文献   

德州市德城区地籍调查数据整理入库工作探讨     

徐健元  李云岭  李靖龙 《山东国土资源》2011,27(5):36-38

全国第二次土地调查是一项重大的国情国力调查,在此次调查中笔者负责德城区调查成果数据入库。该文基于在第二次土地调查中的工作经验,就扫描档案文件、宗地权属信息和宗地界址信息快速整理入库提出几点方法,供广大一线工作者参考。  相似文献   

基于Trimble GPS的高速公路数据采集系统设计与开发     

杨世杰  韩井龙 《测绘信息与工程》2010,35(5):12-13

介绍了高速公路数据采集系统的设计和开发过程,采用了Trimble GPS Pathfinder Tools SDK 2.31和SQLite开源嵌入式数据库,实现了GPS数据接收和存储。  相似文献   

Preliminary Study of the Ability of Large-scale Deformation Observed by Lunar Based InSAR—Taking Vertical Displacement of Solid Earth Tide as an Example     

Chenglong Ma  Xiaodong Chen  Liming Jiang  Heping Sun  Jianqiao Xu  Jinglong Dong  Dewei Li 《地球科学进展》2019,34(2):164-174

Based on the principle of InSAR (Interferometirc Synthetic Aperture Radar) characterized by large-scale, continuity, permanency and dynamic, we took vertical displacement of solid Earth tide as an example to simulate the large-scale deformation observed by lunar based InSAR for the first time in the study and the observation ability was analyzed. Solid Earth tide has a feature of a large-space distribution range and the lunar based InSAR exhibits a feature of an ultra-wide swath imaging. According to these features, a simplified observation geometry model was established and a mid-low latitudes area with 50 degrees span in both longitude and latitude was selected as the simulation area. Then the revisit time intervals of the lunar based SAR for the selected area and the tidal vertical displacements at the points scanned by the radar were calculated. The time differentials were further computed to get the relative vertical deformation of the solid Earth tide. The simulation results show that the revisit period of the lunar based radar is about 24.8 hours and the maximum vertical displacement in 30 days is up to 30 cm. Since the designed accuracy of the lunar based InSAR reaches several centimeters, the observing of the vertical displacement of the solid Earth tide by using the lunar based InSAR is feasible in theory as the maximum magnitude of the vertical displacement is 1 order of magnitude larger than the designed accuracy. Theoretically ,solid Earth tide is observable by using lunar based InSAR in a sizable area.We can also use the observation data to study the temporal and spatial variation characteristics when observation time lasts two revisit periods or more. On the other hand,the result of the study also provides references for the parameter designing of other observations using the lunar based InSAR, especially for observing large-scale geodynamic phenomena.  相似文献   

台湾美浓M_W6.4地震InSAR形变场初步分析     

董景龙  沈强  汪汉胜  江利明  毛松 《大地测量与地球动力学》2017,37(9):893-897

利用欧洲航天局最新发射的宽刈幅、高分辨率Sentinel-1A卫星,第一时间获取2016-02-06台湾美浓MW6.4地震干涉像对,使用D-InSAR技术获取美浓地区的同震形变场。利用震中附近39个同震GPS观测进行对比验证后显示,InSAR获取的同震形变场精度优于1 cm（3σ）。形变发生在宏观震中30 km×30 km范围内,主要表现为沿雷达视线向抬升,最大抬升约12 cm。从形变场空间分布特征可以看出,空间连续性较好,说明宏观震中附近地表未发生明显破裂。宏观震中并不与震中位置重合,而是位于震中西部约15 km处。  相似文献   

长江中下游水阳江流域BZK0402孔多重地层划分及其冰后期海平面变化的沉积响应          下载免费PDF全文

陈忠良  张晋喆  沈仕豪  黄蒙  徐锦龙  葛海影  SimonM.Jowitt 《中国地质》2022,49(2):655-666

[研究目的]开展水阳江流域标准孔BZK0402孔多重地层划分,探讨长江支流水阳江流域冰后期海平面变化的沉积响应以及古丹阳湖的成因和形成时代.[研究方法]以岩石地层为基础,在磁性地层和年代地层的双重约束下,对BZK0402孔进行多重地层划分.对比分析BZK0402孔和长江河谷、长江三角洲等邻区钻孔.[研究结果]BZK04...  相似文献   

测绘地理信息类本科专业“一干两轴三维”人才培养模式建设   总被引：1，自引：1，他引：0  

连达军  张兄武  张序  杜景龙  杨朝辉  严勇  张志敏 《测绘通报》2016,(10):137-140

为优化配置教学资源,提高教学效率,增强专业人才培养特色,提出测绘地理信息类本科专业“一干两轴三维”人才培养模式。该模式以掌握现代测绘地理信息科学技术理论为中心,培养创新研究能力和创新实践能力为主轴,设置工程测量、城市空间信息工程、摄影测量与遥感3个方向;从制订培养方案入手,围绕课程体系建设改革教学模式,针对专业方向强化实践教学;构建了校企合作开放型人才培养体系。该模式目前已经应用,取得了显著效果。  相似文献   

蒙古国植被对干旱响应的敏感性研究   总被引：1，自引：0，他引：1  

吕振涛  李生宇  彭中敏  范敬龙  刘国军  王海峰  孟晓于 《地理研究》2021,40(11):3016-3028

本文分析了蒙古国不同区域、不同土地覆被类型区的植被生长状况对干旱响应的敏感性特征,并探讨了成因。研究表明：① 2001—2019年,蒙古国虽然发生了3次较为严重的干旱事件,但整体上干旱程度呈轻微降低趋势,SPEI出现轻微上升,总体增速为0.001%/a;植被生长状况出现了好转,植被指数也呈上升趋势,总体增速为0.15%/a。② 蒙古国大部分区域植被生长受干旱影响较强,各植被指数与干旱指数呈较明显的正相关关系,在NDVI与SPEI-12的相关性分析中,正相关面积占比达76.36%;而在杭爱山脉和肯特山脉以北降水量丰沛的区域和阿尔泰山脉以南荒漠化严重和植被极为稀少区域,植被生长受干旱影响较弱,植被指数与SPEI相关性较小。③ 不同类型植被对干旱响应的敏感性也有差异,其中草地敏感性最强（0.22）,而森林敏感性最弱（-0.04）。④ 干旱持续时间长短,对植被生长影响有较大差异,蒙古国大部分区域的植被对延续3个月至半年的干旱最为敏感,而年内以7月份干旱对植被影响最强。⑤ 植被对干旱响应的敏感性实质是区域水分平衡的植被影响,对同种植被而言多年平均气温越高或降水量越少,植被对干旱响应的敏感性越强,反之则越弱。本文的研究结果对蒙古国因地制宜开展荒漠化防治具有重要参考价值。  相似文献   

Diffusion Characteristics of Swells in the North Indian Ocean     

Zheng  Chongwei  Liang  Bingchen  Chen  Xuan  Wu  Guoxiang  Sun  Xiaofang  Yao  Jinglong 《中国海洋大学学报(英文版)》2020,19(3):479-488

Research on the diffusion characteristics of swells contributes positively to wave energy forecasting, swell monitoring, and early warning. In this work, the South Indian Ocean westerly index(SIWI) and Indian Ocean swell diffusion effect index(IOSDEI) are defined on the basis of the 45-year(September 1957–August 2002) ERA-40 wave reanalysis data from the European Centre for Medium-Range Weather Forecasts(ECMWF) to analyze the impact of the South Indian Ocean westerlies on the propagation of swell acreage. The following results were obtained: 1) The South Indian Ocean swell mainly propagates from southwest to northeast. The swell also spreads to the Arabian Sea upon reaching low-latitude waters. The 2.0-meter contour of the swell can reach northward to Sri Lankan waters. 2) The size of the IOSDEI is determined by the SIWI strength. The IOSDEI requires approximately 2–3.5 days to fully respond to the SIWI. The correlations between SIWI and IOSDEI show obvious seasonal differences, with the highest correlations found in December–January–February(DJF) and the lowest correlations observed in June–July–August(JJA). 3) The SIWI and IOSDEI have a common period of approximately 1 week in JJA and DJF. The SIWI leads by approximately 2–3 days in this common period.  相似文献   

Observed characteristics of atmospheric ducts over the South China Sea in autumn     

Cheng  Yinhe  Zhou  Shengqi  Wang  Dongxiao  Lu  Yuanzheng  Huang  Ke  Yao  Jinglong  You  Xiaobao 《中国海洋湖沼学报》2016,34(3):619-628

The observed characteristics of lower atmospheric ducts over the South China Sea(SCS) were analyzed based on Global Position Systerm(GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012.Duct occurrence,thickness,and strength over the SCS were about 40%,150-m thick,and 8 M units,respectively,which were larger than during the summer monsoon period.Most ducts occurred at heights 1 500 m and these ducts easily trap electromagnetic wave clusters with wavelengths 2 m.Diurnal variation of the SCS ducts appeared evident.They occurred more often at midnight at higher altitudes(about 1 100 m),with a thickest layer of about 145 m and less frequently during the evening at lower altitudes(about 800 m),with a thinnest layer of about 125 m.Moreover,ducts during the daytime at a mean height of about 900 m,with the greatest strength of about 10 M units.Furthermore,all duct variables observed over the SCS in autumn decreased from north to south.These findings are useful not only in the design of radar and communication systems,but also for evaluating possible effects of anomalous propagation on meteorological radar and military applications.  相似文献