Atherogenic lipid-related risk may not be fully characterized by a single lipid measure. A dual-axis framework combining apolipoprotein B (ApoB), a measure of atherogenic particle number, with the LDL-C to total cholesterol ratio (LDL-C/TC), a derived measure of cholesterol partitioning, has been proposed to characterize lipid-related risk heterogeneity. The position of remnant cholesterol (RC) within this framework remains uncertain. We analyzed 288,257 UK Biobank participants free of cardiovascular disease and lipid-lowering therapy. Participants were classified using dual-axis framework. Associations with incident atherosclerotic cardiovascular disease (ASCVD) were assessed using Cox models. RC was evaluated in combination with these axes across strata, including SCORE2-defined low-to-intermediate risk populations. Over a median follow-up of 13.9 years, the dual-axis framework differentiated ASCVD risk, with the dual-elevated phenotype (ApoB ≥ 90 mg/dL and LDL-C/TC ≥ 0.60) showing the highest risk (adjusted hazard ratio 1.23; 95

Abstract In order to study the explosion characteristics of explosive train in fuze, and provide reference for the design of explosive train, the simulation calculation of explosion characteristics of L-type explosive train is carried out, and a simplified model is established for theoretical analysis. The analysis results show that the initiation point of the L-type explosive train should be designed in the middle and back end of the detonating charge column, so that the detonation pressure at the detonation tube can be larger; The air gap should be reduced as much as possible when designing the explosive train; Proper thickness of metal structures in the explosive train can influent the detonation waveform become more complex shock wave chasing and superposition, which will increase the detonation pressure.

In this study, moist singular vector (MSV) was developed based on GRAPES-GEPS (Global/Regional Assimilation and Prediction System - Global Ensemble Prediction System), the adjoint model of large-scale condensation and cumulus deep convection in GRAPES-4DVar (Four-dimensional variational assimilation). Five consecutive days of numerical experiments were performed for a preliminary evaluation of MSV. The singular values, horizontal distribution structure, spread of MSVs perturbation and its influence on the ensemble prediction were compared for each group of tests. The results showed that in the middle and high latitudes of the northern and southern hemispheres, the addition of both linearized moist physical processes increased the spread of the mid- and low-level SVs, but the linearized large-scale condensation (LC) process plays a leading role in the structure of MSV. The analysis of ensemble forecast shows the inclusion of moist linearized physical processes led to a greater effect of MSV on the rainfall levels of 10 and 25 mm and a slight improvement in anomaly correlation coefficient (ACC) of the atmospheric circulation field, and more obvious improvement due to linearized large-scale condensation. In the future, continuous multi-year testing and tropical-specific analyses are required for operation.

The community coupler (C-Coupler) for Earth system modelling is a coupler family that was developed in China in 2010. C-Coupler3.0, the latest version, is fully compatible with the previous version, C-Coupler2, and is an integrated infrastructure with new features, i.e. a series of parallel-optimization technologies for accelerating coupling initialization and reducing memory usage, a common halo-exchange library for developing a parallel version of a model, a common module-integration framework for integrating a software module (e.g. a flux algorithm, a parameterization scheme, and a data assimilation method), a common framework for conveniently developing a weakly coupled ensemble data assimilation system, and a common framework for flexibly inputting and outputting fields in parallel. Specifically, C-Coupler3.0 is able to handle coupling under much finer resolutions (e.g. more than 100 million horizontal grid cells) with fast coupling initialization and successful generation of remapping-weight files.

As earth system modeling develops ever finer grid resolutions, the inputting and outputting (I/O) of the increasingly large data fields becomes a processing bottleneck. Many models developed in China, as well as the community coupler (C-Coupler), do not fully benefit from existing parallel I/O supports. This paper reports the design and implementation of a common parallel input/output framework (CIOFC1.0) based on C-Coupler2.0. The CIOFC1.0 framework can accelerate the I/O of large data fields by parallelizing data read/write operations among processes. The framework also allows convenient specification by users of the I/O settings, e.g., the data fields for I/O, the time series of the data files for I/O, and the data grids in the files. The framework can also adaptively input data fields from a time series dataset during model integration, automatically interpolate data when necessary, and output fields either periodically or irregularly. CIOFC1.0 demonstrates the cooperative development of an I/O framework and coupler, and thus enables convenient and simultaneous use of a coupler and an I/O framework.

Abstract Accurate offshore surface wind forecasting is crucial for navigation safety and disaster prevention. However, significant biases exist in forecasting sea surface winds due to the uncertainties in estimating sea surface roughness. In this study, we propose a deep learning‐based scheme (DL2023) for estimating sea surface roughness and integrate it into a regionally coupled ocean‐atmosphere‐wave model. Single‐point experiments demonstrate that DL2023 achieves a remarkable 50% reduction in the Root Mean Square Error (RMSE) compared to the four traditional schemes. During five typhoon cases in August 2020, compared to the four traditional schemes, the RMSEs of forecasted surface winds using DL2023 are reduced by 6.02%–14.75%, 11.17%–18.30%, and 11.91%–19.46% at lead times of 24, 48, and 72 hr, respectively. Thus, the DL2023 scheme, trained using data from the Atlantic Ocean, successfully improves the forecast of surface winds over the Northwest Pacific Ocean.

以太湖隧道某大型基坑工程为背景,构建基于支持向量机方法的智能反演系统,开展室内软土蠕变实验,提出结合智能反演和蠕变实验的分析方法.结合现场监测数据,综合确定相关土层的基本物理力学参数及蠕变相关参数.结合现场超载作用下软土基坑的变形进行分析,验证了该方法在进行软土基坑超载作用下长期稳定性分析及变形预测中的可适用性.将该方法应用于太湖隧道的超载优化设计,取得了良好的效果.

Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Impact of soil freezing-thawing processes on August rainfall over southern ChinaAuthorsKunXiaiDLijuanLiiDYan liTangBinWangiDSee all authors Kun XiaiDCorresponding Author• Submitting AuthorLASG, Institute of Atmospheric Physics, Chinese Academy of SciencesiDhttps://orcid.org/0000-0002-2070-0560view email addressThe email was not providedcopy email addressLijuan LiiDLASG,IAP Chines Academy of SciencesiDhttps://orcid.org/0000-0001-8814-5738view email addressThe email was not providedcopy email addressYan li TangState Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciencesview email addressThe email was not providedcopy email addressBin WangiDLASG, Institute of Atmospheric Physics, Chinese Academy of SciencesiDhttps://orcid.org/0000-0002-3133-7197view email addressThe email was not providedcopy email address

湿奇异向量(Moist Singular Vectors,简称MSVs)是包含了湿物理切线性过程计算得到的奇异向量.研究MSVs对最优化时间间隔(optimization time interval,简称OTI)及模式水平分辨率的敏感性对提高集合预报效果至关重要.本文基于中国气象局数值预报中心自主研发的全球/区域同化和预报系统(Global/Regional Assimilation and Prediction System,简称GRAPES)——全球集合预报系统(Global ensemble prediction system,简称GEPS)业务版本研究了4组不同时空尺度(不同OTI和水平分辨率)下的MSVs,从能量模、能量谱、空间剖面等方面分析热带外MSVs特征,并从等压面变量评分、降水评分、降水概率预报等方面评估不同初值的集合预报效果.结果表明:提高MSVs水平分辨率可使其扰动具有较大的增长率,缩短OTI后MSVs能量向上传播的趋势更明显,并可以在中尺度范围产生较大SVs扰动.不同OTI下初始MSVs相似性较低,结构差异较大.从集合预报的结果来看,OTI为24 h试验的集合扰动能量增长较大,集合离散度在预报的0～96 h有明显提升,特别是2 m温度,且近地面要素的outlier评分也有明显改进.进一步分析发现,提高水平分辨率和缩短OTI的MSVs能够提高降水概率预报,而降水评分显示,同一水平分辨率下,OTI越短评分越好,但是提高MSVs的水平分辨率并不一定会提升小雨到中雨量级的降水评分.

High-resolution sea ice modeling is becoming widely available for both operational forecasts and climate studies. In traditional Eulerian grid-based models, small-scale sea ice kinematics represent the most prominent feature of high-resolution simulations, and with rheology models such as viscous–plastic (VP) and Maxwell elasto-brittle (MEB), sea ice models are able to reproduce multi-fractal sea ice deformation and linear kinematic features that are seen in high-resolution observational datasets. In this study, we carry out modeling of sea ice with multiple grid resolutions by using the Community Earth System Model (CESM) and a grid hierarchy (22, 7.3, and 2.4 km grid stepping in the Arctic). By using atmospherically forced experiments, we simulate consistent sea ice climatology across the three resolutions. Furthermore, the model reproduces reasonable sea ice kinematics, including multi-fractal spatial scaling of sea ice deformation that partially depends on atmospheric circulation patterns and forcings. By using high-resolution runs as references, we evaluate the model's effective resolution with respect to the statistics of sea ice kinematics. Specifically, we find the spatial scale at which the probability density function (PDF) of the scaled sea ice deformation rate of low-resolution runs matches that of high-resolution runs. This critical scale is treated as the effective resolution of the coarse-resolution grid, which is estimated to be about 6 to 7 times the grid's native resolution. We show that in our model, the convergence of the elastic–viscous–plastic (EVP) rheology scheme plays an important role in reproducing reasonable kinematics statistics and, more strikingly, simulates systematically thinner sea ice than the standard, non-convergent experiments in landfast ice regions of the Canadian Arctic Archipelago. Given the wide adoption of EVP and subcycling settings in current models, it highlights the importance of EVP convergence, especially for climate studies and projections. The new grids and the model integration in CESM are openly provided for public use.

1. We design a new tripolar grid generation method for global ocean-sea ice modeling. The generated grid is orthogonal and compatible with ocean and sea ice models. A hierarchy of ocean-sea ice model grid is constructed and incorporated in CESM by using the grid generation method. The generated tripolar grids are regarded as TS045, TS015 and TS005, with the nominal resolution of 0.45o (800x560), 0.15o (2400x1680) and 0.05o (7200x5040), respectively. The resolution range for the grid hierarchy covers climate modeling to sub-mesoscale capable for ocean modeling. 2. Atmosphere forced simulations based on CESM D-type experiments are carried out for TS grid. Both TS045 and TS015 experiments start with no sea ice, integrate for 42 years. TS005 starts from the equilibrium state of TS015 result (36 year), runs for another 7 years. 3. TS0*.grid files include necessary grid information, such as grid latitude, longitude, etc. TS0*.kmt files denote the deepest level at each grid location. Bilinear interpolators from TS grid to atmosphere T62 grid are provided with map*.nc files. The model outputs at year 42 are provided with T*.nc files. The last two kinds of netcdf files are compressed with Linux command "gzip".

地球气候系统模式是开展多学科、多圈层集成研究的重要平台,其发展是国际地学领域特别是全球变化领域竞争的前沿.中国的地球气候系统模式研发工作始于20世纪80年代,最近10年得到快速发展.研发格局上已经形成中国科学院、有关部委和高校三足鼎立的局面.文中在简要回顾中国地球气候系统模式早期发展历史的基础上,总结了中国参加第6次耦合模式比较计划的9个地球气候系统模式的技术特点,初步评估了中国4个模式对全球和东亚气候模拟的基本性能,分析了其在4种共享社会经济路径情景下对全球降水与温度的预估变化及其与平衡态气候敏感度的联系.最后,结合国际态势,从发展的角度提出未来中国气候模式研发工作需要加强的8个方向.

Long-term changes in the soil freezing-thawing depth are an important indicator of climate change. Based on data from 764 meteorological stations across China, we analysed the climatology and variability in the seasonal freezing depth (SFD) during 1965-2013 and investigated the connections among changes in the SFD, meteorological factors (temperature, precipitation, snow depth, freezing index and thawing index) and atmospheric circulations (East Asian winter monsoon [EAWM] and North Atlantic Oscillation [NAO]) in each of 4 sub-regions: northwestern China (W), the Tibetan Plateau (TP) and eastern China (E1 and E2). In addition, the contributions of 2 different factors to variation in the SFD were quantified. The results revealed that during 1965-2013, the SFD noticeably changed from positive to negative anomalies in approximately 1988 for all of the studied regions, exhibiting a significant decreasing trend at rates (mean ± SE) of 0.23 ± 0.03, 0.08 ± 0.01, 0.26 ± 0.03 and 0.24 ± 0.03 cm yr-1 in E1, E2, W and TP, respectively. The air freezing index was strongly correlated with the SFD in the E2 and TP regions, and accounted for 82.6 and 84.9% of the change in SFD, respectively. Snow depth showed a significant association with the variability in SFD only in the E1 region. Compared to the NAO, the EAWM plays an important role in changes in SFD. These findings have implications for further understanding the mechanisms of cold environment changes across China.

森林凋落物是森林生态系统极其重要的组成部分,关系着森林生态系统的物质循环和养分平衡.然而,有关异质性自然森林生态系统中生物与非生物因子对凋落物凋落量的影响机制还存在较大争议.本文以广西弄岗15ha森林动态监测样地中设置的90个凋落物收集器所收集的凋落叶为研究对象,选取2013-2018年连续6年的凋落叶数据探讨了森林叶凋落量的时空动态,旨在深入了解该地区森林生态系统的物质循环过程及凋落量的影响因子.结果 显示:2013-2018年的年均叶凋落量为4,099.44 kg/ha,标准误为232.34,变异系数为0.15,这表明不同年际间叶凋落量存在明显差异;不同年际间叶凋落量的节律性变化为双峰型、三峰型或多峰型,说明不同年份的叶凋落量存在明显的节律性差异,但总体而言高峰期主要出现在每年的春季(3-4月)和秋季(8-10月);生态因子对叶凋落量年际动态存在显著影响,其累计解释率为69.3％,其中海拔对叶凋落量的影响最强,解释率为46.5％;而生物因子如胸径变异系数、单位面积胸高断面积之和和物种丰富度则对叶凋落量的影响较弱.多年的连续监测表明,喀斯特季节性雨林不同年际间叶片的凋落量和节律性存在显著差异,而非生物因子,如海拔是形成叶凋落量空间变异的主要因素.

Abstract Climate models contain atmospheric and oceanic components that are coupled together to simulate the thermodynamic and dynamic processes during air‐sea interactions. Community Earth System Model (CESM version 1.2.1) is a state‐of‐the‐art coupled model that is widely used and participates in Coupled Model Intercomparison Projects. Community Atmospheric Model (CAM), the atmospheric component of CESM, is based on the finite‐volume dynamic core, which utilizes staggered Arakawa‐D grids. However, the dynamics‐physics (D‐P) coupling in CAM causes the prognostic winds of the dynamic core be interpolated onto non‐staggered locations, which affects the wind structure for computing the air‐sea interaction and dynamical coupling. In this study we propose a new scheme that eliminates the extra interpolation during D‐P coupling for the atmosphere‐ocean interaction. We show that it improves the simulated climatology in key regions including eastern boundary upwelling regions and Southern Oceans. Compared with the default scheme, the new approach simulates strong surface wind near coast in eastern boundary upwelling regions. As a result, existing problems of the model, such as warm SST biases in these regions, are reduced. Meanwhile, for Southern Ocean, the prevailing westerlies are enhanced in new scheme, resulting in meridional sea ice transport. As a result, the overestimation of sea ice extent and negative bias in SST is reduced. This new scheme is generally applicable to coupled models with staggered dynamics‐physics, such as spectral‐element method based CAM.

在程锐等(2018)中,我们完成了非静力AREM(Advanced Regional Eta-coordinate Model)模式动力框架设计.本文将通过理想和实例试验检验其模拟能力.设计理想试验并通过与国际成熟的中尺度非静力框架比较,直接检验非静力AREM三维动力框架在细致分辨率(约1 km)下的模拟性能.可以看出,非静力AREM与ARPS(Advanced Regional Prediction System)、WRF(Weather Research and Forecasting Model)模拟出类似的积云对流结构及演变特征,从而基本确证了本文发展的非静力框架的正确性.结合原静力平衡模式的初始化和物理参数化过程,形成非静力AREM模式系统.台风实例模拟表明,粗分辨率下静力、非静力AREM模式性能接近;但在高分辨率下,非静力明显优于静力模式.我们还开展了批量降水试验检验,对非静力AREM模式性能进行了进一步的验证.

Warm bias of modeled sea surface temperature (SST) in the eastern boundary upwelling systems (EBUS) is a ubiquitous feature in coupled climate models. This paper investigates the causes underlying this warm bias, with a focus on the effect of horizontal resolution in the atmospheric component of coupled models, by using Community Earth System Model (CESM) as an example. By breaking down the energy budget of the upper ocean, we conclude that surface net heat flux and Ekman upwelling process exert a considerable influence (over 80%) on upper ocean temperature of EBUS in CESM. Besides, the problem of underestimation of stratocumulus cloud is not present near the coast, and hence not responsible for this warm bias in CESM. On the contrary, downward shortwave radiation bias is overcompensated by longwave radiation and latent flux bias on the open ocean. Therefore, the insufficient ocean dynamic upwelling is the dominantly cause for SST warm bias. Finer horizontal resolution atmosphere component of CESM enables better representation of low-level coastal jet structure, with stronger and closer alongshore wind stress and curl leading to realistic representation of upwelling process and horizontal water mass transportation. Furthermore, low-level coastal jet is shown to be sensitive to coastal mountain topography, especially in South East Pacific region, through both thermodynamic and dynamic atmospheric processes and oceanic response. This article provides further proof of improving coupled climate models in reducing the SST biases in EBUS regions.

The pyramid-prism interface in "point-seed" rapidly grown DKDP (KDxH2-xPO4) crystals affects the quality of tripler-cut samples used in inertial confinement fusion devices. In this study, a cuboid DKDP crystal without a pyramidal sector was rapidly grown. The quality of the cuboid DKDP crystal was evaluated by measuring the deuterium homogeneity, crystalline quality, transmission spectrum, and laser-induced damage performance. The total number N of tripler-cut samples that can be obtained from the cuboid DKDP crystal is easily calculated. The size of the tripler-cut sample is approximately equal to the cross-section of this cuboid DKDP crystal. Moreover, as this cuboid DKDP crystal has a regular shape, calculating the mass of the crystal and accurately controlling the supersaturation of the solution during growth is easy. The successful crystal growth using this proposed approach establishes the possibility of growing large-aperture cuboid DKDP crystals. Currently, research on the rapid growth of a cuboid DKDP crystal with an aperture of more than 40 cm is underway.

To investigate the pyramid–prism (PY–PR) boundary of a rapidly grown KDP crystal, the exact position of the PY–PR boundary of an X-cut rapidly grown KDP sample is determined by measuring the refractive-index non-uniformity.

AREM (Advanced Regional Eta-coordinate Model)对中国暴雨、台风等中尺度天气系统的模拟、预报能力突出.但是伴随模式分辨率的提高,制约该模式发展的一个问题日渐突出,即“静力平衡近似”的约束.本文通过对原静力平衡系统进行修正,引入高阶订正参数定义第三运动方程来构建该模式的非静力动力框架.我们基于Euler原始方程组,有效结合原静力平衡模式的标准层结扣除及IAP(Institute of Atmospheric Physics)变换方法,推导出了球面余纬坐标下的非静力框架,并在E网格和η坐标下进行了时空离散.采用时间两部分离技术进行积分运算以提高计算效率,并通过“追赶法”结合迭代法计算声波.此框架可方便地继承静力平衡框架的特点,最大限度地保留静力平衡框架的优势.理论推导和数值试验表明,当非静力框架退化为静力平衡框架后,方程形式及其模拟结果一致.在文章第二部分将通过理想和实例试验检验非静力模式性能.