风压平衡关系对高分辨率区域模式地面资料同化的影响分析

随着模式分辨率的提高,数值模式可分辨的短波信息增加,以地转平衡为基础的风压平衡约束关系不能完全满足低纬度地区及对流尺度高分辨率模式资料同化的需求。提出了基于多重网格方法构建1 km分辨率数值模式变分同化风压平衡约束关系的方案,基于CMA-MESO (China Meteorological Administration Mesoscale Model)三维变分(Three-Dimensional Variational Data Assimilation,简称3DVAR)和1 km分辨率中尺度区域模式开展了单点同化试验和典型个例分析。单点同化试验表明,气压和风的同化结果在没有平衡约束关系条件下比线性平衡约束下更接近观测。地面自动气象站观测资料同化试验表明新风压平衡约束关系将明显增加模式低层几十千米尺度的分析增量,其次是增加100—200 km尺度的分析增量。新风压平衡约束试验的同化分析增量相对于线性平衡约束的对照试验可以给出更多的增量中心位置,更好描述低层水汽辐合,对模式初始0—3 h降水、0—6 h地面10 m风和地面气压的模拟有改进。研究表明在大尺度风压平衡约束的基础上增加局地无风压平衡约束的订正,可以提高对流尺度天气系统地面短波信息的同化能力,改进高分辨率模式短时临近预报。

GRAPES区域扰动预报模式动力框架设计及检验

设计了适用于四维变分同化系统的扰动预报模式GRAPES_PF。根据GRAPES的地形追随坐标非静力原始方程组,采用小扰动分离方法推导微分形式的线性扰动预报方程组,并利用与GRAPES非线性模式相似的数值求解方案求解线性扰动微分方程组。在设计扰动预报模式时采用了两个时间层半隐式半拉格朗日方案对动量方程、热力学方程、水汽方程和连续方程进行时间差分,空间差分方案的变量分布水平方向采用Arakawa C跳点网格,垂直方向采用Charney/Phillips跳层。利用代数消元法进一步推导得到只包含未来时刻扰动Exner气压的亥姆霍兹方程,进而通过广义共轭余差法(GCR)求解,在此基础上得到未来时刻扰动量的预报值。基于所开发的扰动模式开展了数值试验。首先在非线性模式中施加一个中尺度初始扰动高压,得到初始扰动在非线性模式中的后续演变,然后将相同的初始扰动作为扰动模式的初值进行时间积分,将扰动模式预报的结果与非线性模式的结果做了对比。结果表明,所开发的扰动模式GRAPES_PF较好地模拟了惯性重力内波的传播过程:初始高压扰动激发了一个迅速向外传播的惯性重力内波,在气压场向风场适应的过程中,水平风场、垂直运动、位温和湿度等变量均出现了扰动增量,与非线性模式得到的结果相当接近。GRAPES_PF作为GRAPES非线性模式的合理线性模式为建立基于线性扰动预报的区域四维变分同化系统奠定了科学基础。

基于扰动模式的四维变分资料同化系统框架的设计完善和数值试验

为了建立一个应用于区域数值预报的四维变分资料同化(4DVar)系统,在近期开发的扰动预报模式GRAPES_PF基础上,开发完善增量四维变分同化系统框架。该框架中暂不包含物理过程(长短波辐射、边界层过程、对流参数化和云微物理等)。对比业务使用的GRAPES 3DVar系统,增加了温度控制变量。将无量纲Exner气压与流函数的线性风压平衡方程直接在地形追随垂直坐标面上求解,且通过广义共轭余差法(GCR)求解扰动亥姆霍兹(Helmholtz)伴随方程。利用人造“探空”资料对2015年10月台风“彩虹”进行了理想数值试验。试验结果表明,所开发的扰动四维变分同化框架得到了预期的结果,即同化更多资料并反复受到模式约束的四维变分同化系统能有效改善初值质量,进而改善区域数值预报。建立的区域四维变分同化框架合理可行,为进一步发展包含完整物理过程的区域四维变分同化系统奠定了研究基础。

Improvement of the Surface Pressure Operator in GRAPES and Its Application in Precipitation Forecasting in South China

In this study we investigated the problems involved in assimilating surface pressure in the current global and regional assimilation and prediction system, GRAPES. A new scheme of assimilating surface pressure was proposed, including a new interpolation scheme and a refreshed background covariance. The new scheme takes account of the differences between station elevation and model topography, and it especially deals with stations located at elevations below that of the first model level. Contrast experiments were conducted using both the original and the new assimilation schemes. The influence of the new interpolation scheme and the updated background covariance were investigated. Our results show that the new interpolation scheme utilized more observations and improved the quality of the mass analysis. The background covariance was refreshed using statistics resulting from the technique proposed by Parrish and Derber in 1992. Experiments show that the updated vertical covariance may have a positive influence on the analysis at higher levels of the atmosphere when assimilating surface pressure. This influence may be more significant if the quality of the background field at high levels is poor. A series of assimilation experiments were performed to test the validity of the new scheme. The corresponding simulation experiments were conducted using the analysis of both schemes as initial conditions. The results indicated that the new scheme leads to better forecasting of sea level pressure and precipitation in South China, especially the forecast of moderate and heavv rain.

Radar Data Assimilation of the GRAPES Model and Experimental Results in a Typhoon Case

Constructing βmesoscale weather systems in initial fields remains a challenging problem in a mesoscale numerical weather prediction （NWP） model. Without vertical velocity matching the βmesoscale weather system, convection activities would be suppressed by downdraft and cooling caused by precipitating hydrom eteors. In this study, a method, basing on the threedimensional variational （3DVAR） assimilation technique, was developed to obtain reasonable structures of βmesoscale weather systems by assimilating radar data in a nextgeneration NWP system named GRAPES （the Global and Regional Assimilation and Prediction System） of China. Singlepoint testing indicated that assimilating radial wind significantly improved the horizontal wind but had little effect on the vertical velocity, while assimilating the retrieved vertical velocity （taking Richardson’s equation as the observational operator） can greatly improve the vertical motion. Ex periments on a typhoon show that assimilation of the radial wind data can greatly improve the prediction of the typhoon track, and can ameliorate precipitation to some extent. Assimilating the retrieved vertical velocity and rainwater mixing ratio, and adjusting water vapor and cloud water mixing ratio in the initial fields simultaneously, can significantly improve the tropical cyclone rainfall forecast but has little effect on typhoon path. Joint assimilating these three kinds of radar data gets the best results. Taking into account the scale of different weather systems and representation of observational data, data quality control, error setting of background field and observation data are still requiring further indepth study.

T淋巴细胞亚群在胶质瘤患者外周血及癌组织中水平及意义

目的 观察胶质瘤患者外周血及癌组织T淋巴细胞亚群水平变化,探讨其在胶质瘤中的作用。方法 2022年12月—2023年8月新疆医科大学第二附属医院诊治胶质瘤患者12例为胶质瘤组(根据WHO分级分为低级别组2例和高级别组10例),均行手术切除治疗,术前采集外周血标本,术中收集癌组织及癌旁正常组织标本。健康体检者11例为对照组,体检日采集外周血标本。采用流式细胞术检测外周血和癌组织、癌旁组织CD3^(+)、CD4^(+)、CD8^(+)T淋巴细胞百分比,计算CD4^(+)/CD8^(+);采用免疫组织化学法检测癌组织Ki-67表达情况。比较胶质瘤组与对照组外周血,胶质瘤患者癌组织与癌旁正常组织、外周血与癌组织,低级别组与高级别组外周血、癌组织T淋巴细胞亚群水平。采用Pearson相关法分析胶质瘤患者癌组织T淋巴细胞亚群与Ki-67表达的相关性。结果 胶质瘤组外周血CD4^(+)T淋巴细胞百分比[(41.41±9.16)%]低于对照组[(50.74±0.69)%](t=3.407,P=0.007),CD3^(+)、CD8^(+)T淋巴细胞百分比及CD4^(+)/CD8^(+)与对照组比较差异均无统计学意义(P>0.05)。胶质瘤患者癌组织CD4^(+)、CD8^(+)T淋巴细胞百分比[(58.04±13.76)%、(16.47±9.56)%]均低于癌旁正常组织[(77.43±24.82)%、(25.48±9.01)%](t=5.516,P=0.004;t=2.157,P=0.007),CD3^(+)T淋巴细胞百分比、CD4^(+)/CD8^(+)与癌旁正常组织比较差异均无统计学意义(P>0.05)。高级别组外周血CD4^(+)T淋巴百分比[(43.95±11.53)%]低于低级别组[(49.60±43.95)%](t=2.422,P=0.009),CD8^(+)T淋巴细胞百分比[(29.63±12.48)%]高于低级别组[(22.30±3.59)%](t=2.645,P=0.016),CD3^(+)T淋巴细胞百分比、CD4^(+)/CD8^(+)与低级别组比较差异均无统计学意义(P>0.05);高级别组癌组织CD4^(+)、CD8^(+)T淋巴细胞百分比[(53.80±11.45)%、(13.90±2.81)%]均低于低级别组[(72.90±3.54)%、(28.30±5.52)%](t=2.576,P=0.003;t=3.579,P=0.008),CD4^(+)/CD8^(+)(3.87±0.04)高于低级别组(2.64±0.64)(t=0.645,P=0.030),CD3^(+)T淋巴细胞百分比与低级别组比较差异无统计学意义(P>0.05)。胶质瘤患者癌组织CD3^(+)、CD8^(+)T淋巴细胞百分比均低于外周血(P<0.05),CD4^(+)T淋巴细胞百分比、CD4^(+)/CD8^(+)均高于外周血(P<0.05)。胶质瘤患者癌组织CD3^(+)T淋巴细胞百分比与Ki-67表达呈负相关(r=-0.669,P=0.024),CD4^(+)T淋巴细胞百分比与Ki-67表达呈正相关(r=0.681,P=0.009),CD8^(+)T淋巴细胞百分比、CD4^(+)/CD8^(+)与Ki-67表达均无相关性(r=-0.497,P=0.120;r=0.162,P=0.634)。结论 胶质瘤患者外周血及癌组织T淋巴细胞亚群水平失调,以CD4^(+)T淋巴细胞百分比降低为主;CD4^(+)T淋巴细胞多分布于癌组织,CD8^(+)T淋巴细胞多分布于外周血;癌组织CD4^(+)T淋巴细胞百分比低的胶质瘤患者肿瘤细胞增殖较快。

巨细胞病毒感染与胶质母细胞瘤免疫微环境的关系

目的采用单细胞转录组测序技术分析巨细胞病毒(CMV)感染的胶质母细胞瘤(GBM)组织转录组图谱,探讨CMV感染与GBM免疫微环境的关系。方法2022年12月—2023年8月新疆医科大学第二附属医院诊治GBM患者20例,收集GBM组织,采用胶体金免疫电镜和微滴式数字PCR技术鉴定GBM组织中是否存在CMV颗粒及遗传物质,比较CMV阳性与阴性GBM组织病毒拷贝数。采用单细胞转录组测序技术分析6例CMV阳性和3例CMV阴性GBM组织的转录组图谱,鉴定共表达巨噬细胞标志物和肿瘤细胞标志物的免疫细胞亚群,对该免疫细胞亚群采用免疫荧光染色和流式细胞术验证,并分析差异表达基因及涉及的信号通路。结果胶体金免疫电镜结果显示,CMV阳性GBM组织存在稀少的金标记电子致密颗粒,与CMV颗粒形态一致。微滴式数字PCR结果显示,12例CMV阳性,8例CMV阴性;CMV阳性GBM组织病毒拷贝数[(150±30)copies/mL]高于CMV阴性GBM组织[(10±5)copies/mL](t=7.200,P<0.001)。单细胞转录组测序鉴定出CMV阳性和阴性GBM组织中均存在肿瘤细胞、巨噬细胞、少突胶质细胞、内皮细胞、基质细胞、T淋巴细胞6种主要细胞类型,以及1种新的免疫细胞亚群即共表达巨噬细胞标志物CD68和肿瘤细胞标志物SOX2的双阳性肿瘤相关巨噬细胞(TAM)(CD68^(+)SOX2^(+)TAM)。免疫荧光染色结果显示,CMV阳性GBM组织中CD68和SOX2共表达,CMV阴性GBM组织中CD68和SOX2共表达不明显。流式细胞术分析结果显示,CD68^(+)SOX2^(+)TAM在CMV阳性GBM组织中富集;CMV阳性GBM组织CD68^(+)SOX2^(+)TAM百分比[(4.86±0.25)%]高于CMV阴性GBM组织[(0.94±0.41)%](t=8.160,P<0.001)。功能分析结果显示,CMV阳性和阴性GBM组织CD68^(+)SOX2^(+)TAM的差异表达基因主要与CMV感染有关,涉及病毒蛋白与细胞因子及其受体相互作用的信号通路。结论GBM患者可能存在CMV感染,CMV感染可诱导共表达巨噬细胞和肿瘤细胞标志物的双阳性TAM(CD68^(+)SOX2^(+)TAM)产生从而重塑GBM免疫微环境。

New generation of multi-scale NWP system (GRAPES):general scientific design

A new generation of numerical prediction system GRAPES (a short form of Global/Regional Assimilation and PrEdiction System) was set up in China Meteorological Administration (CMA). This paper focuses on the scientific design and preliminary results of the numerical prediction model in GRAPES, including basic idea and strategy of the general scientific design, multi-scale dynamic core, physical package configuration, architecture and parallelization of the codes. A series of numerical experiments using the real data with horizontal resolutions from 10 to 280 km and idealized experiments with very high resolution up to 100 m are conducted, giving encouraging results supporting the multi-scale application of GRAPES. The results of operational implementation of GRAPES model in some NWP centers are also presented with stress at evaluations of the capability to predict the main features of precipitation in China. Finally the issues to be dealt with for further development are discussed.

Scientific design and preliminary results of three-dimensional variational data assimilation system of GRAPES

The scientific design and preliminary results of the data assimilation component of the Global-Regional Prediction and Assimilation System (GRAPES) recently developed in China Meteorological Administration (CMA) are presented in this paper. This is a three-dimensional variational (3DVar) assimilation system set up on global and regional grid meshes favorable for direct assimilation of the space-based remote sensing data and matching the frame work of the prediction model GRAPES. The state variables are assumed to decompose balanced and unbalanced components. By introducing a simple transformation from the state variables to the control variables with a recursive or spectral filter, the convergence rate of iteration for minimization of the cost function in 3DVar is greatly accelerated. The definition of dynamical balance depends on the characteristic scale of the circulation considered. The ratio of the balanced to the unbalanced parts is controlled by the prescribed statistics of background errors. Idealized trials produce the same results as the analytic solution. The results of real data case studies show the capability of the system to improve analysis compared to the traditional schemes. Finally, further development of the system is discussed.

A new-generation sand and dust storm forecasting system GRAPES_CUACE/Dust:Model development,verification and numerical simulation

Based on the new-generation Global/Regional Assimilation and PrEdiction System(GRAPES) developed by the Numerical Prediction Research Center,China Meteorological Administration and the Chinese Unified Atmospheric Chemistry Environment for Dust Atmospheric Chemistry Module(CUACE/Dust) developed by the Centre for Atmosphere Watch and Services(CAWAS) of the Chinese Academy of Meteorological Sciences(CAMS) ,the China sand and dust storm forecasting system GRAPES /CUACE-Dust model has been established.The latest data of land desertification,optical properties of China sand and dust aerosols,daily soil moisture and snow cover over China main land was introduced in this system.The system showed good performance in mass conservation.The comparisons of real-time prediction outputs with surface observations and aerosol indices derived from TOMS ozone spectrophotometers(TOMS AI) indicate that the model can predict the outbreak,development,transport and depletion processes of sand and dust storms accurately over China and the East Asian region.The system makes real-time quantitative prediction of a series of elements including sand and dust injection from the surface,dry and wet deposition amount,dust concentration and optical depth.We selected 7 major dust storms occurring in April 2006 and analyzed the spatiotemporal distribution patterns of dust emission,dry and wet deposition and atmospheric load in this paper.The results showed that about 225 million tons of dust were emitted into the atmosphere from the deserts over east Asia in that month.The 3 major sand and dust sources were just as the following:The deserts in northern Inner Mongolia and the boundary area around China-Mongolia were the first dust sources with a contribution of 153 million tons accounting for 68%of the total emission.The Taklimakan Desert ranked second and contributed approximately 40 million tons accounting for 17%of the dust emission.The Onqin Daga Sandland emitted about 15 million tons or 7%of the total emission.The contributions from other deserts,sandy lands and abandoned farmlands were about only 8%of the total dust emission.The total deposition over the East Asian region in April 2006 was 136 million tons.The regional distribution of dust deposition showed that the 3 major sources were also the major deposition areas.The deposition amount in the 3 major sources accounted for 78%of the total with about 135 million tons falling back to the source regions.The secondary deposition area was the China mainland downriver,where more than 2 million tons deposited accounting for 16%of the total deposition.The deposition over the region east of 120°E including China off-shore regions,Korean Peninsula,Japan and the West Pacific took only 6%of the total deposition,which was about 850000 tons.The analysis on dry and wet deposition showed that dry deposition dominated in the process,accounting for 94%of the total sand and dust depositions in the period and wet deposition only was around for 6%,since it was generally dry with less rainfall over northern China in April.

The program structure designing and optimizing tests of GRAPES physics

According to the modularization and standardization of program structure in Global/Regional Assimilation and Prediction System (GRAPES), the plug-compatible and transplantable regional meso-scale and global middle-range physics software package is established. The package's component integrality is comparative with the other advanced models physics. A three-level structure of connecting GRAPES physics and dynamic frame has been constructed. The friendly interface is designed for users to plug in their own physics packages. Phenomenon of grid-point storm rainfall in numerical prediction is analyzed with the numerical tests. The scheme of air vertical velocity calculation is improved. Optimizing tests of physics schemes are performed with the correlative parameters adjusting. The results show that the false grid-point storm rainfall is removed by precipitation scheme improving. Then the score of precipitation forecast is enhanced.

Direct assimilation of satellite radiance data in GRAPES variational assimilation system

Variational method is capable of dealing with observations that have a complicated nonlinear relation with model variables representative of the atmospheric state, and so make it possible to directly assimilate such measured variables as satellite radiance, which have a nonlinear relation with the model variables. Assimilation of any type of observations requires a corresponding observation operator, which establishes a specific mapping from the space of the model state to the space of observation. This paper presents in detail how the direct assimilation of real satellite radiance data is implemented in the GRAPES-3DVar analysis system. It focuses on all the components of the observation operator for direct assimilation of real satellite radiance data, including a spatial interpolation operator that transforms variables from model grid points to observation locations, a physical transformation from model variables to observed elements with different choices of model variables, and a data quality control. Assimilation experiments, using satellite radiances such as NOAA17 AMSU-A and AMSU-B (Advanced Microwave Sounding Unit), are carried out with two different schemes. The results from these experiments can be physically understood and clearly reflect a rational effect of direct assimilation of satellite radiance data in GRAPES-3DVar analysis system.