基于CMIP6模式优化集合平均预估21世纪全球陆地生态系统总初级生产力变化

利用国际耦合模式比较计划第六阶段(CMIP6)中18个地球系统模式总初级生产力(GPP)模拟数据,基于传统的多模式集合平均(MME)和可靠集合平均方法(REA),在4个未来情景(SSP1-2.6,SSP2-4.5,SSP3-7.0和SSP5-8.5)下预估了21世纪全球陆地生态系统GPP的变化量,并分析了GPP变化的驱动因子。研究结果表明：在4个未来情景下,基于REA方法预估的全球陆地生态系统年GPP在未来时期(2068—2100年)比历史时期(1982—2014年)分别增长了(14.85±3.32)、(28.43±4.97)、(37.66±7.61)和(45.89±9.21)Pg C,其增量大小和不确定性都明显低于MME方法。在4个情景下,大气CO₂浓度增长对GPP变化的贡献最大,基于REA方法计算的贡献占比分别为140%、137%、115%和75%;除SSP5-8.5(24%)外,其他情景下升温均导致全球陆地生态系统GPP降低(-42%、-37%、-16%),部分抵消了CO₂施肥效应的正面贡献。温度的影响存在纬度差异：升温在低纬度地区对GPP有负向贡献,在中高纬度地区为正向贡献。降水和辐射变化对GPP变化的贡献相对较小。     

THE CHARACTERISTICS OF GENERAL CIRCULATION, POLAR ICE AND SNOW DAYS / COVER OF EXTREMELY SEVERE COLD MONTHS IN SOUTH CHINA WINTER

The work has made a statistic study of the variations of extremely severe cold winter months in the south of China and general circulation and external forcing factors in preceding periods. The result shows that from the current month to the preceding March the subtropical high in the west Pacific is persistently weak or located more to the east and south. When the summer monsoon is weak in East Asia in the year before, the winter monsoon will be strong in the current year in which the extremely severe cold month occurs. The Asian polar vortex expands in the preceding July, August and September and the current winter. The Tibetan Plateau has fewer days of snow cover in the November and December before the cold month occurs. There is less snow in the Tibetan Plateau in the preceding winter / spring of each extremely severe cold month. There are more polar ice in the polar Region for the 11 months before the current February, especially the previous March through August, and in Region in January ~ November before the current cold month of December but less ice in Region in March ~ August.     

SKUA基岩三维地质建模

以天津平原地区某个工区为例,介绍了三维地质模型建模的数据准备,SKUA建模的流程以及模型分析,共使用28条断层,6个地层的地质构造图,3条地质剖面构建了地质结构模型,表明SKUA建模是高效的和实用的。     

挤压地区物理模拟研究进展

构造物理模拟是目前研究构造变形过程与成因机制最为有效的手段。在系统展示并归纳国内外研究成果的基础上, 总结了物理模拟实验的理论、材料及技术进展。在挤压地区, 构造物理模拟已经被证明是一种模拟逆冲褶皱系统演化过程的强有力工具; 在推覆体或双冲构造、冲断带的反转与基底卷入、挤压造山作用与表面过程、挤压地区构造转换带及地幔对流与板块碰撞俯冲等方面取得了很大进展。     

安徽庐枞盆地泥河铁矿床与膏盐层的成因联系及矿床成矿模式

安徽庐枞盆地位于长江中下游断陷带内,地处扬子板块北缘,是长江中下游成矿带中重要的铁铜多金属成矿区和玢岩型铁矿的集中产地。庐枞盆地西北部勘探发现了大型泥河铁矿床,其硫铁矿和硬石膏矿床也达到了中大型规模,矿床中硬石膏在不同蚀变-矿化阶段均广泛发育,具有鲜明的成矿特色。深部勘探揭示庐枞盆地深部存在含石膏沉积地层(膏盐层),但目前膏盐层与成矿作用关系尚未引起研究重视。本文总结和分析了泥河铁矿床的地质地球化学特征,着重分析了膏盐层与铁矿床形成的关系,并在阐明成矿流体系统演化过程和成矿机理的基础上,提出泥河矿床的形成与三叠系膏盐层有着重要的成因关系,膏盐层是泥河铁矿床形成的重要地质条件之一。铁矿床及蚀变围岩中的大量硬石膏主要来自膏盐层;膏盐层为铁的成矿作用提供了大部分硫和矿化剂元素。在此基础上,建立了泥河铁矿床的两期成矿模式,即中晚三叠世含膏盐地层的沉积作用期(预备成矿期)和早白垩世的岩浆热液成矿期。     

Numerical Physical Mechanism and Model of Turbulent Cascades in a Barotropic Atmosphere

In a barotropic atmosphere, new Reynolds mean momentum equauons including turbulent viscosit,dispersion, and instability are used not only to derive the KdV-Burgers-Kuramoto equation but also to analyze the physical mechanism of the cascades of energy and enstrophy. It shows that it is the effects of dispersion and instability that result in the inverse cascade. Then based on the conservation laws of the energy and enstrophy, a cascade model is put forward and the processes of the cascades are described.     

地下水浅埋条件下冬小麦和大豆土壤水分动态预报模型研究

用统计方法和水量平衡法推导出江淮地区潜水蒸发经验计算模型。利用农田水分平衡原理分别在江淮地区建立了引入潜水蒸发量和没有引入潜水蒸发量的冬小麦和大豆土壤水分动态预报模型,并对这两种模型在地下水浅埋条件下的预报准确度进行比较。1980年的比较结果是:当预报时效为10天时,两种作物7个时段的土壤水分平均绝对误差前者为8.2 mm,后者为20.1 mm,平均相对误差分别为2.8%和6.8%。引入潜水蒸发量后,冬小麦和大豆土壤水分动态预报模型的预报准确度明显提高。     

Differences between CMIP6 and CMIP5 Models in Simulating Climate over China and the East Asian Monsoon

We compare the ability of coupled global climate models from the phases 5 and 6 of the Coupled Model Intercomparison Project(CMIP5 and CMIP6, respectively) in simulating the temperature and precipitation climatology and interannual variability over China for the period 1961–2005 and the climatological East Asian monsoon for the period1979–2005. All 92 models are able to simulate the geographical distribution of the above variables reasonably well.Compared with earlier CMIP5 models, current CMIP6 models have nationally weaker cold biases, a similar nationwide overestimation of precipitation and a weaker underestimation of the southeast–northwest precipitation gradient, a comparable overestimation of the spatial variability of the interannual variability, and a similar underestimation of the strength of winter monsoon over northern Asia. Pairwise comparison indicates that models have improved from CMIP5 to CMIP6 for climatological temperature and precipitation and winter monsoon but display little improvement for the interannual temperature and precipitation variability and summer monsoon. The ability of models relates to their horizontal resolutions in certain aspects. Both the multi-model arithmetic mean and median display similar skills and outperform most of the individual models in all considered aspects.     

南京北郊大气垂直扩散参数特征的测量及其应用

利用平面照相法,以江苏南热发电有限责任公司#Q2号烟囱为研究对象,进行了500次拍摄,通过风向风速、云量、太阳高度角等气象数据,确定了不同稳定度下南京北郊大气扩散参数的特征。与P-G扩散曲线对比发现,在强不稳定A、弱不稳定C、中性D层结中,南京北郊的大气垂直扩散参数在距离排放源200 m范围内更不稳定,而在200—1000 m范围内更稳定。其中,不稳定B层结的扩散曲线与P-G扩散曲线一致,较稳定E、稳定F层结出现于白天的频率很低。对比垂直扩散参数幂函数表达式σ_z=γx~α的系数值γ和α,本研究中α值分别比国家标准增加了28. 6%(A层结)、56. 4%(C层结)、30. 4%(D层结),而B层结的α值却比国家标准减少了22. 9%。此外,通过高斯扩散公式计算得到SO_2和NO_X扩散到观测点的浓度,发现该计算值仅占气象楼污染气体监测平台实测SO_2和NO_X浓度的0. 82%和0. 69%。结合风场发现,SO_2和NO_X实测值受观测点东部工业污染物排放的叠加效应影响较大。其中,NO_X的实测值在受到偏东风和偏南风的影响时具有较大值,且在0. 5～1. 5 m·s~(-1)的较弱风速影响时,NO_X的实测值将达到60μg·m~(-3)以上。     

青藏高原大气—植被相互作用的模拟试验——Ⅰ.物理通量和参数

在原大气-植被相互作用模式AVIM的基础上作了改进，包括对值被生理过程，如（1）光合作用：（2）呼吸；（3）分配和（4）物候等新的描述方法。对青藏高原上30个站点进行模拟计算，给出了高压上地表辐射及水热物理通量以及地表拖曳系数和地面反照率的分布特征。模拟结果表明净辐射和感热通量由东南和西北增加，高原西北部地表反照率较高，东南部地表反照率较低。