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Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during the Monsoon Season. Part Ⅰ:Pre-storm Environment and Storm Evolution

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Advances in Atmospheric Sciences 2024年第9期41卷 1115-1131页

作者： Lanqiang BAI Dan YAO zhiyong meng Yu ZHANG Xianxiang HUANG Zhaoming LI Xiaoding YU Foshan Tornado Research Center and China Meteorological Administration Tornado Key LaboratoryGuangdong Meteorological Serviceand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Guangdong 528000China Meteorological Observation Centre CMABeijing 100081China Department of Atmospheric and Oceanic Sciences and China Meteorological Administration Tornado Key LaboratorySchool of PhysicsPeking UniversityBeijing 100871China Guangzhou Meteorological Observatory CMAGuangdong 511430China Foshan Tornado Research Center and China Meteorological Administration Tornado Key LaboratoryCMAGuangdong 528000China China Meteorological Administration Training Center CMABeijing 528000China

The Pearl River Delta(PRD),a tornado hotspot,forms a distinct trumpet-shaped coastline that concaves toward the South China *** the summer monsoon season,low-level southwesterlies over the PRD’s sea surface tend to be turned toward the west coast,constituting a convergent wind field along with the landward-side southwesterlies,which influences regional convective *** two-part study explores the roles of this unique land–sea contrast of the trumpet-shaped coastline in the formation of a tornadic mesovortex within monsoonal flows in this *** I primarily presents observational analyses of pre-storm environments and storm *** rotating storm developed in a lowshear environment(not ideal for a supercell)under the interactions of three air masses under the influence of the land–sea contrast,monsoon,and storm cold *** intersection zone(or“triple point”)is typically characterized by local enhancements of ambient vertical vorticity and *** on a rapid-scan X-band phased-array radar,finger-like echoes were recognized shortly after the gust front intruded on the triple *** over the triple point,they rapidly wrapped up with a well-defined low-level *** is thus presumed that the triple point may have played roles in the mesovortex genesis,which will be demonstrated in Part II with multiple sensitivity numerical *** findings also suggest that when storms pass over the boundary intersection zone in the PRD,the expected possibility of a rotating storm occurring is relatively high,even in a low-shear *** knowledge of such environments provides additional guidance to assess the regional tornado risk.

关键词： tornado mesovortex surface boundary land–sea contrast monsoon

The Impact of Moist Physics on the Sensitive Area Identification for Heavy Rainfall Associated Weather Systems

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Advances in Atmospheric Sciences 2022年第5期39卷 684-696页

作者： Huizhen YU zhiyong meng Qingdao Meteorological Bureau Qingdao 266003China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China

The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical experiments with and without moist *** show that the CNOP with moist physics identifies sensitive areas corresponding to both the lower-(850−700 hPa)and upper-level(300−100 hPa)weather systems,while the CNOP without moist physics fails to capture the sensitive areas at lower *** reasons for the CNOP peaking at different levels can be explained in both algorithm and physics ***,the gradient of the cost function with respect to initial perturbations peaks at the upper level without moist physics which results in the upper-level peak of the CNOP,while it peaks at both the upper and lower levels with moist physics which results in both the upper-and lower-level peaks of the ***,the upper-level sensitive area is associated with high baroclinicity,and these dynamic features can be captured by both CNOPs with and without moist *** lower-level sensitive area is associated with moist processes,and this thermodynamic feature can be captured only by the CNOP with moist *** result demonstrates the important contribution of the initial error of lower-level systems that are related to water vapor transportation to the forecast error of heavy rainfall associated weather systems,which could be an important reference for heavy rainfall observation targeting.

关键词： moist physics heavy rainfall sensitive area CNOP

Preface to the Special Issue:Predictability,Data Assimilation,and Dynamics of High Impact Weather-In Memory of *** ZHANG

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Advances in Atmospheric Sciences 2022年第5期39卷 673-675页

作者： zhiyong meng Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China

It has been two and a half years since Fuqing ZHANG,a distinguished professor in the Department of Meteorology and Atmospheric Science at the Pennsylvania State University(PSU),passed away unexpectedly on 19 July *** special issue is to commemorate *** ZHANG,who has made tremendous contributions on predictability,data assimilation,and the dynamics of high impact weather.

关键词： ZHANG weather assimilation

内蒙古区域数值预报对探空和地面观测资料的敏感性试验研究

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气象 2024年第2期50卷 144-158页

作者：姚乐宝沈丹孟雪峰孙鑫孟智勇黄晓璐叶飞刘林春孙永刚中山大学大气科学学院/广东省气候变化与自然灾害研究重点实验室珠海519082 南方海洋科学与工程广东省实验室(珠海) 珠海519082 内蒙古自治区气象台呼和浩特010051 北京大学物理学院大气与海洋科学系北京100871 中国气象局雷达气象中心长沙气象雷达标校中心长沙410207

基于内蒙古睿图预报系统的低分辨率版本和WRFDA-FSO诊断工具,评估2021年7月现有探空和地面观测对内蒙古睿图预报系统预报的影响。该方法计算代价相对低廉,并允许根据观测变量、观测类型、气压层次、地理区域等观测的子集对观测影响进行... 详细信息

基于内蒙古睿图预报系统的低分辨率版本和WRFDA-FSO诊断工具,评估2021年7月现有探空和地面观测对内蒙古睿图预报系统预报的影响。该方法计算代价相对低廉,并允许根据观测变量、观测类型、气压层次、地理区域等观测的子集对观测影响进行划分。代价函数为以干总能量为度量的背景场和分析场的预报误差之间的差异。结果表明:观测影响的总体总和为负,观测对预报起正贡献作用。对12 h预报误差减小贡献最大的观测来自探空观测的动力变量(U、V风分量)。而单时次单位数量平均观测影响,探空观测的贡献约为地面观测的1/2。探空观测对12 h预报误差减小从近地面层至模式层顶均保持正贡献作用,并在对流层中低层和对流层高空急流层存在两个极大值区域;地面观测在850 hPa以下低层正贡献占比明显。探空观测在被同化系统同化时均总体具有有利的影响,也反映出探空观测数据稳定、质量较高的特征;地面观测对12 h预报误差减小起正贡献作用次数最多的区域在河套地区尤为显著。同时,探讨了需进一步提高地面观测资料同化率的问题。

关键词：数值预报资料同化基于伴随的预报对观测敏感性(FSO) 观测影响

Contributions of Fuqing ZHANG to Predictability,Data Assimilation,and Dynamics of High Impact Weather:A Tribute

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Advances in Atmospheric Sciences 2022年第5期39卷 676-683,I0002-I0016页

作者： zhiyong meng Eugene E.CLOTHIAUX Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Department of Meteorology and Atmospheric Science The Pennsylvania State UniversityUniversity ParkPennsylvania 16802United States

This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year *** fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are *** extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are *** appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists.

关键词： predictability dynamics data assimilation high impact weather Fuqing ZHANG contributions tribute

Assimilation of All-sky Geostationary Satellite Infrared Radiances for Convection-Permitting Initialization and Prediction of Hurricane Joaquin(2015)

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Advances in Atmospheric Sciences 2022年第11期39卷 1859-1872页

作者： Lei ZHU zhiyong meng Yonghui WENG Fuqing ZHANG Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjing 210044China Laboratory for Climate and Ocean–Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China I.M.System Group(IMSG) at Environmental Modeling Center(EMC)NCEPNWSNOAACollege ParkMD 20740USA Department of Meteorology and Atmospheric Science and Center for Advanced Data Assimilation and Predictability TechniquesThe Pennsylvania State UniversityUniversity ParkPennsylvania 16802USA

Intensity forecasting is one of the most challenging aspects of tropical cyclone(TC) forecasting. This work examines the impact of assimilating high-resolution all-sky infrared radiance observations from geostationary satellite GOES-13 on the convection-permitting initialization and prediction of Hurricane Joaquin(2015) with an ensemble Kalman filter(EnKF)based on the Weather Research and Forecasting(WRF) model. Given that almost all operational global and regional models struggled to capture Hurricane Joaquin(2015)'s intensity, this study examines the potential in improving Joaquin's prediction when assimilating all-sky infrared radiances from GOES-13's water vapor channel. It is demonstrated that, after a few 3-hour cycles assimilating all-sky radiance, the WRF model was able to forecast reasonably well Joaquin's intensity,including its rapid intensification(RI). The improvement was largely due to a more realistic initial hurricane structure with a stronger, warmer, and more compact inner-core. Ensemble forecasts were used to further explore the important physical mechanisms driving the hurricane's RI. Results showed that the RI forecasts were greatly impacted by the initial inner-core vortex structure.

关键词： all-sky infrared radiance TC intensity EnKF inner-core structure

Uncertainties and error growth in forecasting the record-breaking rainfall in Zhengzhou,Henan on 19–20 July 2021

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Science China Earth Sciences 2022年第10期65卷 1903-1920页

作者： Yunji ZHANG Huizhen YU Murong ZHANG Yawen YANG zhiyong meng Department of Meteorology and Atmospheric Science Pennsylvania State UniversityUniversity ParkPennsylvania 16802USA Qingdao Meteorological Bureau Qingdao 266003China State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China

This study explores the controlling factors of the uncertainties and error growth at different spatial and temporal scales in forecasting the high-impact extremely heavy rainfall event that occurred in Zhengzhou,Henan Province China on 19−20 July 2021 with a record-breaking hourly rainfall exceeding 200 mm and a 24-h rainfall exceeding 600 *** show that the strengths of the mid-level low-pressure system,the upper-level divergence,and the low-level jet determine both the amount of the extreme 24-h accumulated and hourly rainfall at 0800 *** forecast uncertainties of the accumulated rainfall are insensitive to the magnitude and the spatial structure of the tiny,unobservable errors in the initial conditions of the ensemble forecasts generated with Global Ensemble Forecast System(GEFS)or sub-grid-scale perturbations,suggesting that the predictability of this event is intrinsically *** dominance of upscale rather than upamplitude error growth is demonstrated under the regime of k^(−5/3) power spectra by revealing the inability of large-scale errors to grow until the amplitude of small-scale errors has increased to an adequate amplitude,and an apparent transfer of the fastest growing scale from smaller to larger scales with a slower growth rate at larger *** convective activities play a critical role in enhancing the overall error growth rate with a larger error growth rate at smaller *** addition,initial perturbations with different structures have different error growth features at larger scales in different variables in a regime transitioning from the k^(−5/3) to k^(−3) power *** growth with conditional nonlinear optimal perturbation(CNOP)tends to be more upamplitude relative to the GEFS or sub-grid-scale perturbations possibly owing to the inherited error growth feature of CNOP,the inability of convective parameterization scheme to rebuild the k^(−5/3) power spectra at the mesoscales,and different error growth characteristics in

关键词： Extremely heavy rainfall Forecast error Predictability Ensemble forecast Henan

Radar-based Characteristics and Formation Environment of Supercells in the Landfalling Typhoon Mujigae in 2015

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Advances in Atmospheric Sciences 2022年第5期39卷 802-818页

作者： Lanqiang BAI zhiyong meng Ruilin ZHOU Guixing CHEN Naigeng WU Wai-Kin WONG School of Atmospheric Sciences Sun Yat-sen Universityand Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of Educationand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510640China Hong Kong Observatory Hong Kong 999077China

This study presents the radar-based characteristics and formation environment of supercells spawned by the tornadic landfalling Typhoon Mujigae(2015)in October *** than 100 supercells were identified within a 24-hour period around the time of the typhoon’s landfall,of which three were tornadic with a rotational intensity clearly stronger than those of non-tornadic *** identified supercells were concentrated within a relatively small area in the northeast quadrant beyond 140 km from the typhoon *** supercells were found more likely to form over flat topography and were difficult to maintain in mountainous *** the study period,more supercells formed offshore than *** mesocyclones of the identified supercells were characterized by a small diameter generally less than 5 km and a shallow depth generally less than 4 km above ground *** environmental analysis revealed that the northeast quadrant had the most favorable conditions for the genesis of supercell in this typhoon *** nondimensional supercell composite parameter(SCP)and entraining-SCP(E-SCP)were effective in separating supercell from non-supercell *** though the atmosphere in the typhoon’s northeast quadrant was characterized by an E-SCP/SCP value supportive of supercell organization,orography was an impeditive factor for the supercell *** findings support the use of traditional parameters obtained from midlatitude supercells to assess the supercell potential in a tropical cyclone envelope.

关键词： supercell tropical cyclone atmospheric environment radar meteorology

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接地共面波导与芯片级联结构设计与优化

河北科技大学学报 2024年第4期45卷 373-380页

作者：孟志永吉星照张秀清倪永婧于国庆张明河北科技大学信息科学与工程学院河北石家庄050018

针对传输线与芯片级联时产生阻抗突变,导致传输效率下降的问题,基于接地共面波导与芯片级联结构,提出了一种适用于X~Ka波段的匹配带线解决方法。通过S参数提取芯片的输入阻抗,并对射频电路中的阻抗不连续点进行分析,设计阻抗匹配电路并... 详细信息

针对传输线与芯片级联时产生阻抗突变,导致传输效率下降的问题,基于接地共面波导与芯片级联结构,提出了一种适用于X~Ka波段的匹配带线解决方法。通过S参数提取芯片的输入阻抗,并对射频电路中的阻抗不连续点进行分析,设计阻抗匹配电路并建立三维仿真模型。通过有限元仿真分析,讨论了匹配电路和键合引线中心间距对射频传输性能的影响,对比分析了不同结构及不同匹配电路的传输性能差异。仿真结果显示:在X~Ka波段范围内,匹配电路可令接地共面波导与芯片级联结构的S11-0.19 dB。优化后的接地共面波导与芯片级联结构可在降低传输损耗的同时显著提高射频信号的隔离度,减少信道串扰,为厘米波频段下射频电路的设计提供理论参考。

关键词：微波技术共面波导阻抗匹配金丝键合射频性能