Scaling effects on modeled surface energy-balance components using the NOAH-OSU land surface model

As surface exchange processes are highly non-linear and heterogeneous in space and time, it is important to know the appropriate scale for the reasonable prediction of these exchange processes. For example, the explicit representation of surface variability has been vital in predicting mesoscale weather events such as late-afternoon thunderstorms initiated by latent heat exchanges in mid-latitude regions of the continental United States. This study was undertaken to examine the effects of different spatial scales of input data on modeled fluxes, so as to better understand the resolution needed for accurate modeling. A statistical procedure was followed to select two cells from the Southern Great Plains 1997 hydrology experiment region, each 20 km×20 km, representing the most homogeneous and the most heterogeneous surface conditions (based on soil and vegetation) within the study region. The NOAH-OSU (Oregon State University) Land Surface Model (LSM) was employed to estimate surface energy fluxes. Three scales of study (200 m, 2 and 20 km) were considered in order to investigate the impacts of the aggregation of input data, especially soil and vegetation inputs, on the model output. Model results of net radiation and latent, sensible and ground heat fluxes were compared for the three scales. For the heterogeneous area, the model output at the 20-km resolution showed some differences when compared with the 200-m and 2-km resolutions. This was more pronounced in latent heat (12% decrease), sensible heat (22% increase), and ground heat flux (44% increase) estimation than in net radiation. The scaling effects were much less for the relatively homogeneous land area with 5% increase in sensible heat and 4% decrease in ground heat flux estimation. All of the model outputs for the 2- and 20-km resolutions were in close agreement. The results suggested that, for this study region, soils and vegetation input resolution of about 2 km should be chosen for realistic modeling of surface exchange processes. This resolution was sufficient to capture the effects of sub-grid scale heterogeneity, while avoiding the data and computational difficulties associated with higher spatial resolutions.     

岩质边坡稳定性分析的探讨

通过最大剪应力等值线来确定边坡的滑动面,并与其结构面抗剪强度相比较,给出了确定边坡的稳定系数的方法。     

闽北一次降雹过程的新一代天气雷达回波特征

通过对一次降雹过程的新一代天气雷达资料的强度场、速度场及其它产品的分析，得出对降雹过程不同阶段临近预报有指导意义的结论。     

气象卫星观测资料的分析在城市区域气象环境研究中的应用

目前 ,我国气象部门相当普遍地拥有气象卫星观测资料 ,但是 ,这些资料如何在城市气象服务以及为城市建设规划等方面的决策研究中发挥作用 ,急待进一步研究并开展工作。本文试图通过合理的反演处理 ,给出卫星观测对地面温度的测量结果 ,由此可比较细致地分析了解地面热状况及其与土地利用类型 ,地面覆盖性质等的关系。本文利用有限的 NOAA- AVHRR气象卫星遥感资料 ,采用修正的 Ulivieri分裂窗方法反演出同期的地表温度场 ,通过对北京地区的卫星观测资料进行算例分析 ,揭示出一个 2 0 0 km× 2 0 0 km范围内的地面温度分布特征。反演结果可以明显地揭示出城市热岛现象的变化规律 ,并且能较为清楚地反映出相对的高温区和低温区     

河南降水及最长连续无降水日数时空特征

利用河南省均匀分布的50个台站自建站至1997年近50年的定时降水资料，分析了河南省日小雨、日中雨、日大雨降水过程出现次数和最长连续无降水日数，结果显示，河南省日小雨、日中雨降水过程一年四季均可出现，日大而过程主要出现在3～11月份，冬季仅在豫南一些台站出现，各级降水过程出现次数季节性变化明显，冬季出现最少，夏季出现最多，其地理分布随测站纬度、拔海高度、地形地貌不同有较大差异；最长连续无降水日数也有明显的季节性变化特点，其最大值多出现在冬季，春秋次之，夏季最小，地理位置差异也较明显。     

上地幔顶部折射波走时层析成像研究综述

简要介绍了上地幔顶部折射波走时层析成像研究的发展历程，详细介绍了上地幔项部折射波走时层析成像研究的各种方法并分析了其优缺点，介绍了国内外有关上地幔顶部折射波的研究工作和成果，阐述了上地幔顶部速度结构与构造活动的关系及其地球动力学意义。     

激光照排机输出控制系统设计

简析了激光照排机工作原理，提出了激光照排机输出控制接口的设计方法，重点论述了计算机与激光照排机之间数据缓冲、数据传送、数据分离、信号转换的基本设计思想和实现方法     

地震前兆观测仪器标定问题的探讨

标定工作，在地震前兆观测仪器的研究，使用及所得数据的处理中均已成为一个不可少的环节，但缺少有关标定问题的基石性研究和讨论。本文就标定的定义、种类、目的、要求、存在的问题等做一粗线的讨论，以期今后加强这一工作的深入研究。     

固体粒子的稳泡机理

固体粒子是良好的稳泡剂，其稳泡作用实质是在气－水界面产生吸附，形成固态膜，固态膜致密性强，机械强度高，表面粘度大。固体粒子的润湿性能，粒子大小及形状对固态膜的牢固程度有很大影响。     

新疆对中亚五国的外贸结构,问题及对策

本文在分析新疆对中亚五国的外贸结构基础上，阐述了目前在与中亚五国的贸易中存在的一些问题，提出相应的对策建议，以推动新疆与中亚五国外贸发展的良性循环。