GRAPES模式对长江流域天气预报的检验分析

GRAPES是中国新一代数值天气预报模式。使用GRAPES中尺度模式产品和常规观测资料,分析检验了2005、2006年汛期发生在长江流域的11次主要降水天气过程,得到:GRAPES模式对于长江流域的预报,无论是降水、天气形势还是物理量都有比较强的预报能力;GRAPES模式对级别较大的降水预报容易出现漏报,而不易出现空报,对于10mm以下的雨区预报比较准确,而对于大于50mm的雨区预报,尤其是大于100mm的降水中心存在较大的偏差;对于西太平洋副热带高压的预报比实际情况偏南、偏东;对于水汽通量散度的预报与实际情况比较吻合。     

基于人工神经网络的区域地质灾害危险性预测评价

地质灾害危险性预测评价的准确性,主要取决于基础资料的可靠性和数学模型的合理性。论文结合工程实例,尝试用人工神经网络方法(改进的神经网络BP模型)对区域地质灾害危险性预测进行评价研究。然后与目前常用的方法(如层次分析法、信息量法和模糊综合评判法等)所得出的结果相比较。结果表明,运用人工神经网络方法对区域地质灾害危险性预测评价相对常用方法更准确、可靠,具有一定的实用意义及推广价值。     

内蒙古赛乌素金矿床成矿地质特征及找矿预测

赛乌素金矿床位于华北板决北缘、狼山-白云鄂博裂谷带白云鄂博群浅变质岩系内.矿床成因属浅成中低温热液型金矿床,矿石类型以石英脉型为主,尖灭再现、膨大收缩、雁列侧伏特征明显.区内哈拉忽鸡复背斜及EW、NW向断裂为主要控矿构造,具多期性、叠加性特点.根据区域金成矿规律、控矿地质条件、探采对比以及隐伏矿体的发现,证实南北矿带具备中深部和边部找矿潜力.     

石河子夏季高温过程的环流特征分析

应用1994—2003年NCEP逐日再分析资料,对石河子地区10a夏季出现的10次持续性高温天气过程进行了综合分析,总结了石河子地区高温天气的主要环流及相关物理量的特征,提出了石河子地区夏季高温天气的预报模型。     

凤山县地质灾害统计分析及预报方法

通过对凤山县地质灾害统计分析，提出了降雨是诱发地质灾害的主要因素，建立地质灾害气象条件等级预报的简易方法。     

Traffic Assignment Forecast Model Research in ITS

As an important role in the development of ITS, traffic assignment forecast is always the research focus. Based on the analysis of classic traffic assignment forecast models, an improved traffic assignment forecast model, multi-ways probability and capacity constraint (MPCC) is presented. Using the new traffic as- signment forecast model to forecast the traffic volume will improve the rationality and veracity of traffic as- signment forecast.     

德国降水预报产品的应用和检验

利用德国降水预报输出的24和48h降水预报产品,对2005年1—12月巴音郭楞蒙古自治州(简称巴州,下同)9个气象站分别进行了降水预报效果的检验分析,统计分析其在各月、各季、年的降水预报能力,得出其空报率较大,准确率和漏报率较低,但对巴州南部地区的大降水天气有一定的指导意义。     

Seasonal Transition Features of Large-Scale Moisture Transport in the Asian-Australian Monsoon Region

Using NCEP/NCAR reanalysis data for the period of 1957-2001, the climatological seasonal transition features of large-scale vertically integrated moisture transport （VIMT） in the Asian-Australian monsoon region are investigated in this paper. The basic features of the seasonal transition of VIMT from winter to summer are the establishment of the summertime ＂great moisture river＂ pattern （named the GMR pattern） and its eastward expansion, associated with a series of climatological events which occurred in some ＂key periods＂, which include the occurrence of the notable southerly VIMT over the Indochina Peninsula in mid March, the activity of the low VIMT vortex around Sri Lanka in late April, and the onset of the South China Sea summer monsoon in mid May, among others. However, during the transition from summer to winter, the characteristics are mainly exhibited by the establishment of the easterly VIMT belt located in the tropical area, accompanied by some events occurring in ＂key periods＂. Further analyses disclose a great difference between the Indian and East Asian monsoon regions when viewed from the meridional migration of the westerly VIMT during the seasonal change process, according to which the Asian monsoon region can be easily divided into two parts along the western side of the Indochina Peninsula and it may also denote different formation mechanisms between the two regions.     

Impacts of Coastal SST Variability on the East Asian Summer Monsoon

The impacts of the seasonal and interannual SST variability in the East Asia coastal regions （EACRSST） on the East Asian summer monsoon （EASM） have been examined using a regional climate model （PδRCM9） in this paper. The simulation results show that the correlation between the EACRSST and the EASM is strengthened after the mid-1970s and also the variability of the EACRSST forcing becomes much more important to the EASM interannual variability after the mid-1970s. The impacts of the EACRSST on the summer precipitation over each sub-region in the EASM region become weak gradually from south to north, and the temporal evolution features of the summer precipitation differences over North and Northeast China agree well with those of the index of EASM （IEASM） differences.
The mechanism analyses show that different EACRSST forcings result in the differences of sensible and latent heat flux exchanges at the air-sea interface, which alter the heating rate of the atmosphere. The heating rate differences induce low level air temperature differences over East Asia, resulting in the differences of the land-sea thermal contrast （LSTC） which lead to 850 hPa geopotential height changes. When the 850 hPa geopotential height increases over the East Asian continent and decreases over the coast of East China and the adjacent oceans during the weakening period of weakens consequently. On the contrary, the EASM enhances during the strengthening period of the LSTC.     

Intercomparisons of land-surface parameterizations coupled to a limited area forecast model

The goal of the Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) is to improve the understanding of the interactions between the atmosphere and the continental surface in climate and weather forecast models. In PILPS Phase 4(b), selected schemes are coupled to the Limited Area Prediction System (LAPS) developed by the Australian Bureau of Meteorology. To facilitate the comparison of PILPS schemes' behavior within LAPS, a single mode of coupling is selected: explicit coupling. This type of coupling is more flexible and avoids most of the problems raised when interchanging the surface schemes. Exploratory tests are conducted. Initially, experiments are run in which the land-surface schemes use the same parameters as in their original host models. Then, in other runs, the most important surface parameters are set constant in an attempt to reduce the scatter amongst the schemes' results. In order to understand the impact of initialisation of soil moisture on the schemes' results some extreme cases (wet and dry) are performed. The partitioning between surface fluxes is studied as well as the soil moisture budget. Both regional and local results are analysed. Sensitivity between LSS is found in the precipitation field with rainfall over the Australian continent altering by about 20%, but no significant change is found in the net radiation. The scatter in the surface energy fluxes amongst the schemes is large (up to 300 W m⁻² locally, during the daytime peak) but is seldom affected by the choice of surface parameters. The dynamical range of flux partitioning between extremely dry and wet initialisation varies strongly amongst the schemes. Some major shortcoming with the BUCKET approach are seen in the re-evaporation of convective precipitation over dry land, in the very large evaporation from wet surfaces and the diurnal cycle of surface temperature.