Study on multi-scale blending initial condition perturbations for a regional ensemble prediction system

An initial conditions (ICs) perturbation method was developed with the aim to improve an operational regional ensemble prediction system (REPS). Three issues were identified and investigated: (2) the impacts of perturbation scale on the ensemble spread and forecast skill of the REPS; (3) the scale characteristic of the IC perturbations of the REPS; and (4) whether the REPS's skill could be improved by adding large-scale information to the IC perturbations. Numerical experiments were conducted to reveal the impact of perturbation scale on the ensemble spread and forecast skill. The scales of IC perturbations from the REPS and an operational global ensemble prediction system (GEPS) were analyzed. A "multi-scale blending" (MSB) IC perturbation scheme was developed, and the main findings can be summarized as follows: The growth rates of the ensemble spread of the REPS are sensitive to the scale of the IC perturbations; the ensemble forecast skills can benefit from large-scale perturbations; the global ensemble IC perturbations exhibit more power at larger scales, while the regional ensemble IC perturbations contain more power at smaller scales; the MSB method can generate IC perturbations by combining the small-scale component from the REPS and the large-scale component from the GEPS; the energy norm growth of the MSB-generated perturbations can be appropriate at all forecast lead times; and the MSB-based REPS shows higher skill than the original system, as determined by ensemble forecast verification.     

背景误差水平相关结构对四维变分资料同化的影响研究

为考察GRAPES全球四维变分同化（4DVar）的分析增量在谱空间的时间演变特征,分析当同化时间窗起始时刻与终止时刻背景误差水平相关特征明显不一致时对分析与预报造成的影响,对GRAPES全球4DVar的背景误差水平相关采用二阶自回归模型（SOAR）、集合资料同化生成扰动样本估计的水平相关模型以及基于这两者的背景误差谱空间融合模型进行比较。结果表明,SOAR的分析增量在20波以上的天气尺度波动的分析信息明显不足,而将集合资料同化样本所计算的水平相关的功率谱方差与SOAR功率谱方差进行融合,水平相关特征呈现出多尺度水平相关的特点,可以更好地吸纳观测信息,显著改善北半球形势场、温度与风场预报效果,南半球也有改善,对赤道地区的影响中性。表明研究发展的融合水平相关方案合理、实用。      

An Implementation of Full Cycle Strategy Using Dynamic Blending for Rapid Refresh Short-range Weather Forecasting in China

The partial cycle(PC) strategy has been used in many rapid refresh cycle systems(RRC) for regional short-range weather forecasting. Since the strategy periodically reinitializes the regional model(RM) from the global model(GM)forecasts to correct the large-scale drift, it has replaced the traditional full cycle(FC) strategy in many RRC systems.However, the extra spin-up in the PC strategy increases the computer burden on RRC and generates discontinuous smallscale systems among cycles. This study returns to the FC strategy but with initial fields generated by dynamic blending(DB) and data assimilation(DA). The DB ingests the time-varied large-scale information from the GM to the RM to generate less-biased background fields. Then the DA is performed. We applied the new FC strategy in a series of 7-day batch forecasts with the 3-hour cycle in July 2018, and February, April, and October 2019 over China using a Weather Research and Forecast(WRF) model-based RRC. A comparison shows that the new FC strategy results in less model bias than the PC strategy in most state variables and improves the forecast skills for moderate and light precipitation. The new FC strategy also allows the model to reach a balanced state earlier and gives favorable forecast continuity between adjacent cycles. Hence, this new FC strategy has potential to be applied in RRC forecast systems to replace the currently used PC strategy.     

压裂液快速混配技术的研究与应用

水力压裂是低渗透油藏改造的重要措施,压裂液性能则是影响压裂增产效果的一个关键因素,配液质量好、配液效率高是压裂液配制的发展趋势。通过分析当前压裂液配制难题,以及稠化剂和固体添加剂的特性,指出制约配液快速性的关键因素。基于实验研究成果,提出一种压裂液快速配制新工艺,并采用PLC控制,实现配液过程自动化。新的配液工艺和配液装备已经在大庆油田应用两年,工业化应用表明：该工艺胶液粘度释放快,胶液中没有水包粉现象,且具有计量精度高、添加剂混合均匀,发液速度快等诸多优点,证实了新工艺的合理性和有效性。     

3个代数曲面的高光滑拼接

利用计算机代数方法，讨论3个代数曲面的高光滑拼接，并将其转化为求解齐次线性方程组的问题，从而给出3个代数曲面GC^2拼接的条件．在数学软件的辅助下，给出具体实例．     

基于反距离加权法的混采地震数据分离方法

为将混合地震记录分离为单炮地震记录,笔者采用基于反距离加权的迭代分离方法,在非共炮点域对伪分离数据进行混叠噪声的压制,将其变换回共炮点域,得到分离后的单炮地震记录。模拟数据和实际数据的处理结果证明,本方法能够有效地实现混合数据分离。相较于单独使用多级中值滤波方法,本分离方法能更好的保留有效信息。     

煤岩学在炼焦配煤中的应用研究

通过10kg小焦炉结焦性实验,对煤岩参数与煤的结焦性关系进行了研究,提出了炼焦配煤的煤岩参数及ΣI-R_r,m-R_r直方图配煤法。结果表明,当单种煤的惰性组分含量ΣI=20%~35%、镜质组平均随机反射率R_r,m=1.15%~1.35%时,煤具有良好的结焦性。北京焦化厂用ΣI-R_r,m-R_r直方图配煤法指导炼焦配煤,提高了焦炭质量,获得了较好的经济效益。      

掺水工艺实施后存在问题及解决办法

2007年1月,腰滩油田全面实施掺水工艺。工艺实施初期,因原油物性差、油井分散、单井产量低、新井生产无水采油周期短、油井产液含水率上升快等导致了掺水量过大的问题,使站区日处理液量增加、原油销售超标,严重影响油田的正常生产。为保证掺水工艺在腰滩油田的顺利实施,依据掺水理论,结合油田实际,通过现场简化流程、完善加药方式、制定合理工作制度等措施,使掺水工艺在该油田得到了正常运行,达到了生产稳定、节能降耗、提高经济效益的目的。     

三个二次代数曲面的低次拼接

用计算机代数方法，研究了三个二次曲面的光滑拼接，给出了二次拼接曲面存在的判别方法，及计算拼接曲面的Matlab程序。     

基于GIS的铁矿资源配矿管理系统设计与实现

以司家营研山铁矿为例,选取GIS组件式开发模式,以矿区的高程点、台阶、矿体块段的空间数据和属性数据为基础数据,以矿石质量均衡计算方法为算法指导,设计了铁矿配矿管理系统,实现了矿区数据的图表结合式可视化管理,实现了配矿计划的自动化、科学编制,为工作人员的配矿工作创建了全新模式,对高效利用矿产资源,降低生产成本,保证企业持续稳定发展具有重要意义。