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Evaluation of the Momentum Closure Schemes in MPAS-Ocean

Journal of Ocean University of China 2018年第2期17卷 227-243页

作者： ZHAO Shimei liu yudi liu Wei College of Meteorology and Oceanography Nanjing University of Science and Technology

In order to compare and evaluate the performances of the Laplacian viscosity closure, the biharmonic viscosity closure, and the Leith closure momentum schemes in the MPAS-Ocean model, a variety of physical quantities, such as the relative reference potential energy(RPE) change, the RPE time change rate(RPETCR), the grid Reynolds number, the root mean square(RMS) of kinetic energy, and the spectra of kinetic energy and enstrophy, are calculated on the basis of results of a 3D baroclinic periodic channel. Results indicate that: 1) The RPETCR demonstrates a saturation phenomenon in baroclinic eddy tests. The critical grid Reynolds number corresponding to RPETCR saturation differs between the three closures: the largest value is in the biharmonic viscosity closure, followed by that in the Laplacian viscosity closure, and that in the Leith closure is the smallest. 2) All three closures can effectively suppress spurious dianeutral mixing by reducing the grid Reynolds number under sub-saturation conditions of the RPETCR, but they can also damage certain physical processes. Generally, the damage to the rotation process is greater than that to the advection process. 3) The dissipation in the biharmonic viscosity closure is strongly dependent on scales. Most dissipation concentrates on small scales, and the energy of small-scale eddies is often transferred to large-scale kinetic energy. The viscous dissipation in the Laplacian viscosity closure is the strongest on various scales, followed by that in the Leith closure. Note that part of the small-scale kinetic energy is also transferred to large-scale kinetic energy in the Leith closure. 4) The characteristic length scale L and the dimensionless parameter Г in the Leith closure are inherently coupled. The RPETCR is inversely proportional to the product of Г and L. When the product of Г and L is constant, both the simulated RPETCR and the inhibition of spurious dianeutral mixing are the same in all tests using the Leith closure

关键词： 3D baroclinic eddy momentum closure grid Reynolds number the reference potential energy(RPE) baroclinic adjustment kinetic energy enstrophy

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Spurious Dianeutral Mixing in a Global Ocean Model Using Spherical Centroidal Voronoi Tessellations

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Journal of Ocean University of China 2016年第6期15卷 923-935页

作者： ZHAO Shimei liu yudi College of Meteorology and Oceanography People's Liberation Army University of Science and Technology

In order to quantitatively evaluate the spurious dianeutral mixing in a global ocean model MPAS-Ocean （Model for Prediction Across Scales） using a spherical centroidal voronoi tessellations developed jointly by the National Center for Atmospheric Research and the Los Alamos National Laboratory in the United States, we choose z＊ vertical coordinate system in MPAS-Ocean, in which all physical mixing processes, such as convection adjustment and explicit diffusion parameter schemes, are omitted, using a linear equation of state. By calculating the Reference Potential Energy （RPE）, front revolution position, time rate of RPE change, probability density function distribution and dimensionless parameter 2＂, from the perspectives of resolution, viscosity, Horizontal Grid Reynolds Number （HGRN）, Rea, and momentum transmission scheme, using two ideal cases, overflow and baroclinic eddy channel, we qualitatively analyze the simulation results by comparison with the three non-isopycnal models in Ilicak et al. （2012）, i.e., MITocM, MOM, and ROMS. The results show that the spurious dianeutral mixing in the MPAS-Ocean increases over time. The spurious dianeutral transport is proportional to the HGRN directly and is reduced by increasing the lateral viscosity or using a finer resolution to control HGRN. When the HGRN is less than 10, spurious transport is reduced significantly. When using the proper viscosity closure, MPAS-Ocean performs better than MIT6c and MOM, closely to ROMS, in the 2D case without rotation, and much better than the above-mentioned three ocean models under the condition of 3D space with rotation due to the cell area difference between the hexa- gon cell and the quadrilateral cell with the same resolution. Both the Zalesak （1979） flux corrected transport scheme and Leith closure in MPAS-Ocean play an excellent role in reducing spurious dianeutral mixing. The performance of Leith scheme is preferable to the condition of three-dimensional baroclinic eddy.

关键词： MPAS-Ocean spurious dianeutral mixing Reference Potential Energy (RPE) Leith scheme Horizontal Grid Rey-nolds Number (HGRN)

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PpARF6 acts as an integrator of auxin and ethylene signaling to promote fruit ripening in peach

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Horticulture Research 2023年第9期10卷 151-164页

作者： Xiaomei Chen yudi liu Xian Zhang Beibei Zheng Yuepeng Han Ruo-Xi Zhang CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenThe Innovative Academy of Seed Design of Chinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences 19A YuquanluBeijing 100049China Hubei Hongshan Laboratory Wuhan 430070China

Although auxin is known to induce ethylene biosynthesis in some Rosaceae fruit crops,the mechanisms underlying the auxin–ethylene interaction during fruit ripening remain largely ***,the regulatory role of an auxin response factor,PpARF6,in fruit ripening was investigated in *** fruits showed accelerated ripening after treatment with auxin and PpARF6 was found to be significantly ***6 not only could induce ethylene synthesis by directly activating the transcription of ethylene biosynthetic genes,but also competed with EIN3-binding F-box proteins PpEBF1/2 for binding to ethylene-insensitive3-like proteins PpEIL2/3,thereby keeping PpEIL2/3 ***,PpARF6 showed an interaction with PpEIL2/3 to enhance the PpEIL2/3-activated transcription of ethylene biosynthetic ***,ectopic overexpression of PpARF6 in tomato accelerated fruit ripening by promoting the expression of genes involved in ethylene synthesis and fruit *** summary,our results revealed a positive regulatory role of PpARF6 in peach fruit ripening via integrating auxin and ethylene signaling.

关键词： interaction integrating thereby

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A PpEIL2/3–PpNAC1–PpWRKY14 module regulates fruit ripening by modulating ethylene production in peach

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Journal of Integrative Plant Biology 2024年第11期66卷 2470-2489页

作者： yudi liu Wen Xiao Liao Liao Beibei Zheng Yunpeng Cao Yun Zhao Ruo-Xi Zhang Yuepeng Han State Key Laboratory of Plant Diversity and Specialty Crops Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China Hubei Hongshan Laboratory Wuhan 430070China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Hybrid Rice Department of Plant SciencesCollege of Life SciencesWuhan UniversityWuhan 430072China Sino-African Joint Research Center Chinese Academy of SciencesWuhan 430074China

WRKY transcription factors play key roles in plant resistance to various stresses,but their roles in fruit ripening remain largely ***,we report a WRKY gene PpWRKY14 involved in the regulation of fruit ripening in *** expression of PpWRKY14 showed an increasing trend throughout fruit ***14was a target gene of PpNAC1,a master regulator of peach fruit ***14 could directly bind to the promoters of PpACS1 and PpACO1 to induce their expression,and this induction was greatly enhanced when PpWRKY14 formed a dimer with ***,the transcription of PpNAC1 could be directly suppressed by two EIN3/EIL1 genes,PpEIL2 and *** PpEIL2/3 genes were highly expressed at the early stages of fruit development,but their expression was programmed to decrease significantly during the ripening stage,thus derepressing the expression of *** results suggested a PpEIL2/3–PpNAC1–PpWRKY14 module that regulates fruit ripening by modulating ethylene production in *** results provided an insight into the regulatory roles of EIN3/EIL1 and WRKY genes in fruit ripening.

关键词： EIL ethylene NAC1 Prunus persica ripening WRKY

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Effects of Different Woodland Types on Soil Properties and Soil Nematode Community Structure

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Journal of Landscape Research 2017年第2期9卷 33-37页

作者： liu yudi CHENG Yanhong Shanghai Academy of Landscape Architecture Science and Planning Shanghai Engineering Research Center of Challenging Urban Sites National Engineering and Technology Research Center for Red Soil Improvement Jiangxi Institute of Red Soil

Upland red soil has strong acidity and low fertility, different woodland types produce varying impacts on soil properties and nematode communities. To explore the response of soil, 2 different types of woodland were selected to investigate the changes of soil properties and nematode communities compared to wasteland. The results showed that the content of soil organic carbon and total nitrogen in chestnut forest soil were the highest, 16.41 g/kg and 0.46 g/kg respectively; while the highest contents of soil microbial biomass carbon, nitrogen and phosphorus appeared in wasteland soil, and basal respiration of wasteland soil was 28.36 mg CO_2/kg·d, significantly higher than that of the other 2 soils(p <0.05). The nematode abundance also reached the peak in wasteland soil. Three types of soil exhibited a completely different nematode community structure: the dominant trophic group in wasteland soil was herbivores,while omnivores/predators and bacterivores in forest from farmland and chestnut forest soil, *** influence of different types of woodland on ecological indices of nematode communities was not consistent. Degradation trends of soil properties and nematode communities were presented in the 2woodland types compared with wasteland soil. These results are instructive for the local woodland planning.

关键词： Different types of woodland Soil nematode Community structure

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基态位涡径向分布对浅水涡旋系统动力稳定性的影响分析

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地球物理学报 2018年第6期61卷 2207-2219页

作者：刘爽钟玮刘宇迪中国人民解放军国防科技大学气象海洋学院南京211101

本文基于正压浅水模型,分析基态位涡(Potential Vorticity:PV)结构对热带气旋(Tropical Cyclone:TC)类涡旋系统稳定性及其波动特征的影响.通过引入基态PV结构参数:宽度δ(眼墙内外边界涡度发生陡变的半径长度之比)和中空度γ(眼心相对... 详细信息

本文基于正压浅水模型,分析基态位涡(Potential Vorticity:PV)结构对热带气旋(Tropical Cyclone:TC)类涡旋系统稳定性及其波动特征的影响.通过引入基态PV结构参数:宽度δ(眼墙内外边界涡度发生陡变的半径长度之比)和中空度γ(眼心相对涡度与内核区域平均相对涡度之比),设计具有相同基流最大切向风速和最大风速半径的170组不同基态PV环结构的敏感性试验,并讨论了不同基态PV结构下涡旋系统最不稳定波数(the most unstable wavenumber:MUWN)和系统最不稳定模态(the most unstable mode of System:MUMS)的特征频率及其不稳定增长率的大小.结果指出:当PV环较宽,系统表现为低波数最不稳定,相应的MUMS为低频波且增长率小;当PV环较窄,系统表现为高波数不稳定,且PV环越实最不稳定波数越高;当PV环窄且空时,MUMS均为中高频波动,且不稳定增长率随PV环的宽度变窄和中空度变空而明显增大.分析典型PV结构下系统演变特征可知,当PV环较宽,MUMS表现为具有平衡约束的低频波动的线性不稳定特征;当PV环趋向窄且空时,MUMS的平衡性约束趋向弱化,同时不稳定增长表现为明显的指数型增长.进一步讨论系统内部非对称结构的形成和传播机制发现,对于弱不稳定的PV环来说,低波数波最不稳定的特征波动具有典型涡旋Rossby波特征;而对于强不稳定的PV环来说,高波数不稳定的特征波动混合波性质明显.

关键词：热带气旋(TC) 位涡(PV) 动力稳定性结构参数最不稳定模态

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基态位涡径向分布对浅水涡旋系统演变的影响分析PartⅡ:扰动发展和结构变化

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地球物理学报 2018年第9期61卷 3592-3606页

作者：刘爽钟玮刘宇迪中国人民解放军国防科技大学气象海洋学院南京211101

本文在基态位涡(Potential Vorticity,PV)径向分布和基态涡旋强度对热带气旋(Tropical Cyclone,TC)类涡旋系统稳定性特征影响的研究基础上,结合理想试验和数值模拟诊断分析基态PV径向分布对扰动增长和系统结构变化的影响.基于线性正压... 详细信息

本文在基态位涡(Potential Vorticity,PV)径向分布和基态涡旋强度对热带气旋(Tropical Cyclone,TC)类涡旋系统稳定性特征影响的研究基础上,结合理想试验和数值模拟诊断分析基态PV径向分布对扰动增长和系统结构变化的影响.基于线性正压浅水模型,设计三种典型基态PV中空结构下基态涡旋强度对系统稳定性影响的敏感性试验.结果表明:基态涡旋的强度主要影响稳定性的强弱,强度越强,不稳定增长率越大,而基态PV径向分布对系统最不稳定波动性质起着决定作用.分析不同波数下扰动的发展及不同波数间扰动的相互作用可知,对于宽且实的PV环,系统稳定性主要取决于低波数不稳定,且最不稳定波数扰动的发展具有明显的优势地位;对于窄且空的PV环,系统稳定性主要取决于高波数不稳定,且多个高波数下增长最快模态的不稳定增长率值十分接近.利用模态线性叠加法讨论扰动增长对系统结构变化的影响表明:最不稳定波数的扰动发展对系统结构变化有关键影响,而多个波数的扰动不稳定增长相当时,不同波数的扰动发生相互作用从而影响系统结构变化.最后,利用实际个例模拟资料分析基态PV径向分布及其变化对TC结构和强度的影响表明:TC内核区出现的多边形眼墙结构与当前时刻基态PV径向分布所决定的最不稳定波数有很好的对应关系,同时基态PV径向分布变化所反映出的系统动力稳定性强弱与TC强度发展阶段具有很好的相关性.

关键词：基态位涡径向分布动力不稳定最不稳定模态多边形眼墙

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中东太平洋热带辐合带降水统计特征及其与厄尔尼诺的相关性

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地球物理学报 2018年第1期61卷 80-90页

作者：朱金双刘宇迪国防科技大学气象海洋学院南京211101

利用GPCP(Global Precipitation Climatology Project)与CMAP(CPC Merged Analysis of Precipitation)降水资料以及欧洲天气预报中心月平均SST(Sea Surface Temperature)资料,统计分析了中东太平洋热带辐合带(Centre and Eastern Pacific ITCZ,CEP-ITCZ)降水在两类厄尔尼诺年的基本特征及其与两类厄尔尼诺的相关性.结果表明:在普通年份,CEP-ITCZ平均位置约为7.6°N,强度7.25mm/day,东部型厄尔尼诺年位置偏南约2.9°,强度增强1.9mm/day;而中部型厄尔尼诺年位置偏南仅有0.2°,强度增强1.7 mm/day.不同Nio海区对CEPITCZ位置与强度的影响具有显著差异,与CEP-ITCZ位置相关性最大的海区为超前一个月的Nio 3海区,而与CEP-ITCZ强度相关性最大的海区则为超前一个月的Nio 3.4(8月—次年2月)或Nio 4(3—7月)海区,影响CEP-ITCZ位置的海区主要为东太平洋,影响CEP-ITCZ强度的海区则为中太平洋.此外,CEP-ITCZ位置和强度的异常对SST异常的敏感性均在4月份达到最强,11月份达到最弱.

关键词：中东太平洋热带辐合带(ITCZ) 厄尔尼诺

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风的垂直切变对滞弹性大气中静力适应过程的影响

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地球物理学报 2018年第1期61卷 65-79页

作者：郭海龙刘宇迪国防科学技术大学气象海洋学院南京211101

本文基于描写滞弹性大气静力适应过程的线性方程组,从波动频散关系、气团运动规律和能量转换的角度出发,研究了水平基流及其垂直切变对该模式大气静力适应过程的影响.构造四种水平基流垂直分布模型进行比较,分别为常数型、线性切变型、... 详细信息

本文基于描写滞弹性大气静力适应过程的线性方程组,从波动频散关系、气团运动规律和能量转换的角度出发,研究了水平基流及其垂直切变对该模式大气静力适应过程的影响.构造四种水平基流垂直分布模型进行比较,分别为常数型、线性切变型、反气旋切变型和气旋切变型,得到结论:(1)具有重力波性质的波动是滞弹性大气静力适应过程中扰动能量传播的方式,当垂直折射指数大于零时,基本气流及其垂直切变的存在,不仅改变了波动频率的大小,而且改变波动传播的方向;(2)在静力适应过程中气块的运动轨迹呈椭圆形,水平基流及其垂直切变影响椭圆的扁率,同时也影响扰动物理量之间的偏振关系;(3)水平基流的垂直切变是扰动能量和水平基流能量发生转换的媒介,当存在垂直向上的动量输送时,正的垂直风切变对应扰动能量的衰减,水平基流能量的增加,负的垂直风切变对应扰动能量的增加,水平基流能量的衰减;(4)不同的风的垂直切变模型,对静力适应过程的影响不同;对于水平基流呈反气旋切变型和气旋切变型,扰动发展的波动垂直结构为,急流轴上方波动等相位线自下而上向西倾斜,急流轴下方波动等相位线自下而上向东倾斜,反之亦然.

关键词：风的垂直切变滞弹性大气静力适应能量转换

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论不同模式大气中的静力适应过程

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地球物理学报 2018年第1期61卷 52-64页

作者：郭海龙刘宇迪董毅国防科学技术大学气象海洋学院中国人民解放军93420部队

为了研究大气静力平衡适应过程的本质,利用波动理论和能量转换角度,分别对完全可压缩的等温大气模型、滞弹近似下的等温大气模型和层结中性大气模型进行研究比较.结果表明:大气静力平衡适应过程的本质是声波和混合声重力波对扰动能量的... 详细信息

为了研究大气静力平衡适应过程的本质,利用波动理论和能量转换角度,分别对完全可压缩的等温大气模型、滞弹近似下的等温大气模型和层结中性大气模型进行研究比较.结果表明:大气静力平衡适应过程的本质是声波和混合声重力波对扰动能量的频散过程,滞弹近似模型和层结中性模型均不能完全描述此适应过程;在波动假设下,此三类大气模型中扰动物理量之间的偏振关系同波动的性质有关,气团的运动方程均为椭圆方程,声波和混合声重力波对气团运动的作用差异较显著.大气静力平衡适应过程中扰动能量以有效势能、有效弹性势能、动能或波动能量的形式存在并相互转换;扰动有效势能与其他形式能量之间的转换与混合声重力波或者重力内波有关,扰动有效弹性势能与其他形式能量之间的转换与声波有关.在完全可压缩的等温大气模型中,扰动有效势能增加1个单位,其中69.9%来自扰动垂直动能,其余30.1%来自扰动有效弹性势能.

关键词：静力平衡适应波动理论能量转换偏振关系

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