Analysis on monthly-averaged distribution of sea surface wind and wave over the seas southeast of Asia using ERS-2 scatterometer data

The wind system over the seas southeast of Asia (SSEA) plays an important role in China's climate variation. In this paper, ERS scatterometer winds covering the period from January 2000 to December 2000 and the area of 2-41 °N, 105- 130°E were analyzed with a distance-weighting interpolation method and the monthly mean distribution of the sea surface wind speed were given. The seasonal characteristics of winds in the SSEA were analyzed. Based on WAVEWATCH Ⅲ model, distribution of significant wave height was calculated.     

A Statistical Analysis on the E ect of Vertical Wind Shear on Tropical Cyclone Development

Using tropical cyclone (TC) best track and intensity of the western North Pacific data from the Joint TyphoonWarning Center (JTWC) of the United States and the NCEP/NCAR reanalysis data for the period of 1992-2002, the effects of vertical wind shear on TC intensity are examined. The samples were limited to the westward or northwestward moving TCs between 5°N and 20°N in order to minimize thermodynamic effects. It is found that the effect of vertical wind shear between 200 and 500 hPa on TC intensity change is larger than that of the shear between 500 and 850 hPa, while similar to that of the shear between 200 and 850 hPa. Vertical wind shear may have a threshold value, which tends to decrease as TC intensifies. As the intensifying rate of TC weakens, the average shear increases. The large shear has the obvious trend of inhibiting TC development. The average shear of TC which can develop into typhoon (tropical depression or tropical storm) is below 7 m s-1 (above 8 m s-1).     

厦门GPS基准站建设与试运行

全面叙述中国地壳运动观测网络中25个基准站之一——福建GPS基准站的设计、选址、建造和仪器安装等建设过程及试运行至今的情况和有关参数。其中对某些防护措施如防雷措施有较详细说明。为今后GPS基准站的建设提供了系统性的经验。     

Influence of coronal mass ejection on geomagnetic activity during 1988–1993

The most rapid and dramatic evolution in the solar corona occurs in events now known as Coronal Mass Ejections (CMEs). There have considerable importance for our understanding of the evolution of the mass and energy injected into the interplanetary medium. In this work, we have studied the relation of CMEs with geomagnetic activity for the period of 1988 to 1993. Not all CMEs are capable of producing geomagnetic disturbances. Our study indicates that the maximum chance of a geomagnetic disturbance occurs two to three days after a CME in association with B-type solar flares.     

冕洞演化与太阳活动周的关系及在日地预报中的应用

冕洞的研究在近二十多年里取得了丰硕的成果。本文回顾了冕洞的发现及观测历史，系统阐述了冕洞的结构特征、形成及演化规律，讨论了冕洞对日地空间产生的影响，冕洞与超级活动区的关系以及冕洞在太阳活动预报中所起的作用，在此基础上利用１９７０—１９９５年的冕洞资料对冕洞的时空分布和磁极性演化规律与太阳活动周的关系，以及冕洞与太阳风速度、地磁扰动等方面进行分析研究，得出以下结论：（１）冕洞在南北半球的分布在形态上基本是对称的，但在冕洞数量上北半球稍占优势；（２）冕洞的盛衰演化呈周期性，表现为赤道冕洞周期与黑子周期是完全一致的，极冕洞周期与黑子周期相位相差１８０°；（３）赤道冕洞的纬度分布随太阳活动周上升而上升，当太阳活动周达到极大值时，它也达到极大，然后再随太阳活动周下降而下降，极冕洞的纬度延伸方向演化与赤道冕洞相反；（４）极冕洞的极场呈１１年周期性，并且极场反转出现在太阳活动峰年期间；（５）太阳风和地磁扰动与冕洞的演化有着密切的关系     

Sub-Alfvénic flows in the quiet and recurrent solar winds

Observed instances are given in this paper to show that sub-Alfvénic flow can be formed in the quiet and recurrent low-speed solar wind streams. This kind of flow appears in regions with abnormal enhancement of Alfvénic speed and is associated with a specific type of magnetic configuration.     

超声波测风仪设计中几个问题的探讨

通过比较Gill仪器的Winsonic 2D测风仪和螺旋浆式风速风向计05103L的实测效果,分析了超声波测风仪测风的特点.进而分析了几种超声波测风的检测机理、系统组成和设计的注意事项;同时探讨了如何解决超声波测风仪目前使用中存在的一些问题(如:全天候使用、环境影响补偿等).最后讨论了超声波的传输特性和大气中的杂质对风速、风向测量的影响.     

GPS参考站网络的多路径误差建模技术研究

通过研究多路径误差的周日重复性特征,将参考站网络多路径历史数据用于减弱参考站网络基线解算中的多路径效应影响,以提高网络解算(尤其指低高度角卫星和新升卫星)的初始化进程及可靠性。通过分析多路径误差的产生机理,研究多路径误差与信噪比信息的强相关关系,建立信噪比相关网络内插模型(SNRIM),用于流动用户位置高精度多路径改正数的实时计算。最后通过四川GPS观测网络实验,验证上述方法在网络高精度实时定位领域应用的有效性及可靠性。     

基于GIS的油田井位自动成图系统研究

针对油田生产中油水井数据的特点和管理需求,设计并开发了油田井位自动成图系统:基于Oracle9i与ArcSDE9.0创建空间数据库;基于ASP.NET技术开发浏览器端更新与维护属性数据;基于C与MapObjects2.3开发客户端实现成图及应用功能;对自动成图原理、远程数据访问、图属互查等功能提供了实现方法。     

JSCORS的基准站分布设计与试验

具有实时定位服务功能的连续运行卫星定位服务系统(CORS)是当代GPS发展的热点之一,江苏省连续运行参考站网络是我国首批省级的连续运行的参考站网络系统。基准站分布设计是JSCORS整体设计与建设的一项重要内容,科学、合理地选择基准站址,有利于高质量、高稳定地发挥JSCORS的作用,其选址试验也为今后在其他地区建立CORS基准站提供了宝贵的工程经验。