有限区域短期数值预报业务系统简介

简要介绍了空军气象中心投入业务使用的《空军有限区域短期数值预报业务系统》的概况、采用的主要技术，检验评分结果，最后给出了天气学个例检验结果。     

DIAGNOSTIC ANALYSIS AND VERIFICATION OF PREDICTION OF THE TROPICAL PACIFIC SEA SURFACE TEMPERATURE ANOMALIES DURING 1997 ~ 1998

By comparing with ENSO events that ever happened in the history, the basic features and probable causes of the anomalous sea surface temperature of the tropical Pacific Ocean during 1997 and 1998 have been analyzed diagnostically. It is found that the 1997/1998 El Nino had significant abnormalities and peculiarities. It differs from the previous El Ni?o events falling into the simple “eastern pattern” or “western pattern”. The predictions of 1997/1998 El Ni?o event have also been tested with an intermediate ocean-atmosphere coupled dynamic model. The results show that the skills of the 0～24 lead month forecasts for the warm event are all above 0.5. The predictions of the mature phase and the later stages of the warm event are better than those of the beginning phase.     

Assessing spatial and attribute errors in large national datasets for population distribution models: a case study of Philadelphia county schools

Geospatial technologies and digital data have developed and disseminated rapidly in conjunction with increasing computing efficiency and Internet availability. The ability to store and transmit large datasets has encouraged the development of national infrastructure datasets in geospatial formats. National datasets are used by numerous agencies for analysis and modeling purposes because these datasets are standardized and considered to be of acceptable accuracy for national scale applications. At Oak Ridge National Laboratory a population model has been developed that incorporates national schools data as one of the model inputs. This paper evaluates spatial and attribute inaccuracies present within two national school datasets, Tele Atlas North America and National Center of Education Statistics (NCES). Schools are an important component of the population model, because they are spatially dense clusters of vulnerable populations. It is therefore essential to validate the quality of school input data. Schools were also chosen since a validated schools dataset was produced in geospatial format for Philadelphia County; thereby enabling a comparison between a local dataset and the national datasets. Analyses found the national datasets are not standardized and incomplete, containing 76 to 90 percent of existing schools. The temporal accuracy of updating annual enrollment values resulted in 89 percent inaccuracy for 2003. Spatial rectification was required for 87 percent of NCES points, of which 58 percent of the errors were attributed to the geocoding process. Lastly, it was found that by combining the two national datasets, the resultant dataset provided a more useful and accurate solution.     

A One-dimensional Ensemble Forecast and Assimilation System for Fog Prediction

A probabilistic fog forecast system was designed based on two high resolution numerical 1-D models called COBEL and PAFOG. The 1-D models are coupled to several 3-D numerical weather prediction models and thus are able to consider the effects of advection. To deal with the large uncertainty inherent to fog forecasts, a whole ensemble of 1-D runs is computed using the two different numerical models and a set of different initial conditions in combination with distinct boundary conditions. Initial conditions are obtained from variational data assimilation, which optimally combines observations with a first guess taken from operational 3-D models. The design of the ensemble scheme computes members that should fairly well represent the uncertainty of the current meteorological regime. Verification for an entire fog season reveals the importance of advection in complex terrain. The skill of 1-D fog forecasts is significantly improved if advection is considered. Thus the probabilistic forecast system has the potential to support the forecaster and therefore to provide more accurate fog forecasts.     

光学测微器的原理、检定及误差分析

着重讨论了高精度光学测微器的基本工作原理、检定方法及误差分析。     

1997/1998年热带太平洋海温异常的诊断分析与预报检验

通过与历史上已发生的ENSO事件的比较，对1997－1998年热带太平洋海温异常的基本特征和可能成因进行了诊断分析，发现1997／1998年E1Nino事件具有显著的异常性和独特性，不同于以往单纯的东部型或西部型E1Nino。对用一个简化海气耦合动力学模式做1998／1998年E1Nino事件的预报进行检验。结果表明该模式对这次暖事件超前0－24个月的预报技巧均在0．5以上，模式对暖事件的成熟位相及以后阶段的预报比对暖事件的开始阶段预报得好。     

黄沙坪矿田的综合找矿模式及其在隐伏矿床预测中的应用

黄沙坪矿田的综合找矿模式可概括为已知黄沙坪铅锌矿床成矿模式、地质地球化学及地球物理找矿标志以及最优找矿方法。黄沙坪铅锌矿床成矿母岩与中酸性高侵位岩体有关,倒转背斜轴部及其纵横断裂交汇处控制矿床,走向逆冲断裂带、间层断裂或虚脱带、岩体侵入接触带等控制矿体;矿床范围内有重力、磁力、电性、放射性等异常,出现成矿元素及重矿物指示标志;探查岩体(探岩)、圈定远景区(圈区)找矿床赋存部位(找位)、寻工业矿体(寻体)是最优找矿方法。此综合找矿模式在隐伏矿床预测中的应用经钻探验证取得了积极效果。     

A radar-based verification of precipitation forecast for local convective storms

Local flash flood storms with a rapid hydrological response are a real challenge for quantitative precipitation forecasting (QPF). It is relevant to assess space domains, to which the QPF approaches are applicable. In this paper an attempt is made to evaluate the forecasting capability of a high-resolution numerical weather prediction (NWP) model by means of area-related QPF verification. The results presented concern two local convective events, which occurred in the Czech Republic (CR) on 13 and 15 July 2002 and caused local flash floods. We used the LM COSMO model (Lokall Model of the COSMO consortium) adapted to the horizontal resolution of 2.8 km over a model domain covering the CR. The 18 h forecast of convective precipitation was verified by using radar rainfall totals adjusted to the measured rain gauge data. The grid point-related root mean square error (RMSE) value was calculated over a square around the grid point under the assumption that rainfall values were randomly distributed within the square. The forecast accuracy was characterized by the mean RMSE over the whole verification domain. We attempt to show a dependence of both the RMSE field and the mean RMSE on the square size. The importance of a suitable merger between the radar and rain gauge datasets is demonstrated by a comparison between the verification results obtained with and without the gauge adjustment. The application of verification procedure demonstrates uncertainties in the precipitation forecasts. The model was integrated with initial conditions shifted by 0.5° distances. The four verifications, corresponding to the shifts in the four directions, show differences in the resulting QPF, which depend on the size of verification area and on the direction of the shift.     

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。