集合数值预报发展与研究进展

较系统地概述了集合预报系统发展过程与集合预报中的主要研究问题，总结了集合预报概念、系统组成、初始扰动理论技术和产品解释与应用原理的研究成果，简单分析了近年来集合预报中的一些研究热点，介绍了先进国家集合预报的发展计划。     

非线性病态问题解算的扰动分析

非线性病态问题除了要分析模型本身的病态性外,还要考虑非线性最小二乘算法中初始值选取、正交化过程等造成的扰动对病态分析的影响.在广义条件数定义的基础上,推导非线性病态法方程解的扰动估计式,并以扰动估计式为基础,讨论非线性算法对非线性病态问题判断和分析的影响,产生影响的原因主要包括线性近似时系数矩阵的扰动、附加的截断误差及...     

夏季东亚西风急流Rossby波扰动异常与中国降水

利用1958～2003年NCAR/NCEP再分析和中国160 站月降水资料,探讨沿东亚西风急流Rossby波扰动动能异常对东亚夏季风环流和中国夏季（6～8月）降水的影响及其响应机理。研究发现:（1）夏季东亚西风急流Rossby波扰动动能加强（减弱), 东亚西风急流位置偏南（北)、强度偏强（弱）。（2）该扰动动能具有显著的年际和年代际变化特征, 1958～1978年处于年代际偏弱阶段,1979～1998年处于年代际偏强阶段。（3）该扰动动能加强（减弱), 200 hPa 辐合区位于30?N以南（以北）西太平洋地区,此时,500 hPa 西太平洋副热带高压位于30?N以南（以北), 850 hPa 反气旋性距平环流出现在东亚30?N以南（以北）地区,而30?N以北（以南）为气旋性距平环流,东亚热带季风环流加强（减弱), 梅雨锋加强（减弱), 夏季中国东部降水中间多、南北少（中间少、南北多）。（4）东亚高、中、低层大气环流对高层东亚西风急流Rossby波扰动动能强弱响应由对流层上层散度场及垂直速度场变化完成。     

Impact of Soil Moisture Uncertainty on Summertime Short-range Ensemble Forecasts

To investigate the impact of soil moisture uncertainty on summertime short-range ensemble forecasts(SREFs), a fivemember SREF experiment with perturbed initial soil moisture(ISM) was performed over a northern China domain in summertime from July to August 2014. Five soil moisture analyses from three different operational/research centers were used as the ISM for the ensemble. The ISM perturbation produced notable ensemble spread in near-surface variables and atmospheric variables below 800 h Pa, and produced skillful ensemble-mean 24-h accumulated precipitation(APCP24) forecasts that outperformed any single ensemble member. Compared with a second SREF experiment with mixed microphysics parameterization options, the ISM-perturbed ensemble produced comparable ensemble spread in APCP24 forecasts, and had better Brier scores and resolution in probabilistic APCP24 forecasts for 10-mm, 25-mm and 50-mm thresholds. The ISM-perturbed ensemble produced obviously larger ensemble spread in near-surface variables. It was, however, still under-dispersed, indicating that perturbing ISM alone may not be adequate in representing all the uncertainty at the near-surface level, indicating further SREF studies are needed to better represent the uncertainties in land surface processes and their coupling with the atmosphere.     

初始冰核浓度对冷云对流性降水影响的数值试验

本文利用二维滞弹性非静力平衡云模式［1］,通过改变初始冰核浓度,研究其对冷云对流性降水的影响。模拟结果表明：增大初始自然冰核浓度,对对流强弱和云状影响不大,但对云内的微观结构有很大的影响,即云内冰粒子提前产生,云冰和雪含量增大,并且可以削弱地面累积固态和液态降水量。并分析了导致这些结果的原因以及要削弱局地暴雨,必须初始播撒大量冰核的同时,增大初始云滴浓度（CCN）。     

Identification of the sensitive area for targeted observation to improve vertical thermal structure prediction in summer in the Yellow Sea

The sensitive area of targeted observations for short-term(7 d) prediction of vertical thermal structure(VTS) in summer in the Yellow Sea was investigated. We applied the Conditional Nonlinear Optimal Perturbation(CNOP)method and an adjoint-free algorithm with the Regional Ocean Modeling System(ROMS). We used vertical integration of CNOP-type temperature errors to locate the sensitive areas, where reduction of initial errors is expected to yield the greatest improvement in VTS prediction for the selected verification area. The identified sensitive areas were northeast-southwest orientated northeast to the verification area, which were possibly related to the southwestward background currents. Then, we performed a series of sensitivity experiments to evaluate the effectiveness of the identified sensitive areas. Results show that initial errors in the identified sensitive areas had the greatest negative effect on VTS prediction in the verification area compared to errors in other areas(e.g., the verification area and areas to its east and northeast). Moreover, removal of initial errors through deploying simulated observations in the identified sensitive areas led to more refined prediction than correction of initial conditions in the verification area itself. Our results suggest that implementation of targeted observation in the CNOP-based sensitive areas is an effective method to improve short-term prediction of VTS in summer in the Yellow Sea.     

Vertical groundwater flux estimation from borehole temperature profiles by a numerical model,RFLUX

We developed a numerical model, RFLUX, which uses the heat tracer method for vertical groundwater flux estimation, and applied it to the Leizhou Peninsula, South China, to provide information to inform local groundwater resource utilization and management. The temperature–depth (TD) profiles of 24 boreholes, along with the observed ground surface temperature (GST) and surface air temperature (SAT) series in recent decades, were collected in this area. Underground TD data demonstrated the capacity to identify groundwater flow patterns, and local GST and SAT data demonstrated a strong correlation with each other over monthly, seasonal, and annual scales. In the RFLUX model, the average GST and SAT series were applied as an upper boundary condition, and a nonlinear initial condition was set using an analytical solution from the literature. The model results of selected TD profiles demonstrated that the annual vertical groundwater flux was about 0.15 m a^?1, which tended to be overestimated if a linear initial condition was used. This model can be easily applied with minor modifications, considering its clear purpose and simplicity.     

Propagation of Rayleigh waves in fluid‐saturated non‐homogeneous soils with the graded solid skeleton distribution

The propagation characteristic of Rayleigh waves in a fluid‐saturated non‐homogeneous poroelastic half‐plane is addressed. Based on Biot's theory for fluid‐saturated media, which takes the inertia, fluid viscosity, mechanical coupling, compressibility of solid grains, and fluid into account, the dispersion equations of Rayleigh waves in fluid‐saturated non‐homogeneous soils/rocks are established. By considering the shear modulus of solid skeleton variation with depth exponentially, a small parameter, which reflects the relative change of shear modulus, is introduced. The asymptotic solution of the dispersion equation expressing the relationship between the phase velocity and wave number is obtained by using the perturbation method. In order to analyze the effects of non‐homogeneity on the propagation characteristic of Rayleigh waves, the variation of the phase velocity with the wave number is presented graphically and discussed through numerical examples. Copyright © 2016 John Wiley & Sons, Ltd.     

炉霍县幅地质调查新成果及主要进展

对如年各组进行了重新厘定,并根据其中的放射虫硅质岩及辉长岩U—Pb测试结果,将其时代限制在中三叠世拉丁期至晚三叠世诺利期。如年各组中蛇绿岩残片的首次发现,表明炉霍-道孚构造带曾经有初始洋盆的形成。     

工程VSP与地震CT联合探测方法及其在岩土工程的应用

垂直地震剖面（Vertical Seismic Profile,简称VSP）和层析成像（Computerized Tomography,简称CT）方法,不仅能够使用统一的数学方法描述（如射线理论）,并且在其勘探实践活动中完全可融为一体而成为优化技术组合下的高分辨工程物探方法.特别是在井间地震CT数据采集现场施工中,充分利用VSP和井间CT数据采集方式的兼容性和优化观测系统参数设计,几乎可以不增加野外工作费用,就能够同时获取井间地震CT数据和施测孔的逆向VSP数据体.如井中排列多点激发,地面各接收点构成多偏移距逆向VSP道集,并可组成关于孔中各炮点的变偏移距逆向VSP道集.这种高分辨技术组合在近地表大中型岩土洞室工程测试环境中更易于实现.本文简述了工程VSP与地震CT数据一体化观测系统,介绍了联合速度反演初始模型的建立与成像处理流程,给出VSP和CT联合成像方法应用于三峡大坝工程物探检测中的一个实例简介,最后得出相关结论并提出建议.