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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 2019.This special issue is to commemorate Prof.Fuqing ZHANG,who has made tremendous contributions on predictability,data assimilation,and the dynamics of high impact weather.

关键词： ZHANG weather assimilation

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 physics.Results 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 levels.The reasons for the CNOP peaking at different levels can be explained in both algorithm and physics aspects.Firstly,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 CNOP.Secondly,the upper-level sensitive area is associated with high baroclinicity,and these dynamic features can be captured by both CNOPs with and without moist physics.The lower-level sensitive area is associated with moist processes,and this thermodynamic feature can be captured only by the CNOP with moist physics.This 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

A Tri-mode of Mock-Walker Cells

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Advances in Atmospheric Sciences 2024年第4期41卷 671-679页

作者： Han QIN Ji NIE Zhiyong MENG Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China China Meteorological Administration Tornado Key Laboratory Foshan 528061China

This work uses cloud-resolving simulations to study mock-Walker cells driven by a specified sea surface temperature(SST).The associated precipitation in the mock-Walker cells exhibits three different modes,including a single peak of precipitation over the SST maximum(mode 1),symmetric double peaks of precipitation straddling the SST maximum(mode 2),and a single peak of precipitation on one side of the SST maximum(mode 3).The three modes are caused by three distinct convective activity center migration traits.Analyses indicate that the virtual effect of water vapor plays an important role in differentiating the three modes.When the SST gradient is large,the virtual effect may be strong enough to overcome the temperature effect,generating a low-level low-pressure anomaly below the ascending branch of the Walker cell off the center.The results here highlight the importance of the virtual effect of water vapor and its interaction with convection and large-scale circulation in the Walker circulation.

关键词： Walker circulation cloud-resolving simulation virtual effect

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 career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special 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 mm.Results 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 UTC.The 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 limited.The 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 scales.Moist convective activities play a critical role in enhancing the overall error growth rate with a larger error growth rate at smaller scales.In 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 law.Error 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 the k^(−5/3) and k^(−3) regimes.

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

Climatology of tropical cyclone tornadoes in China from 2006 to 2018

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Science China Earth Sciences 2020年第1期63卷 37-51页

作者： Lanqiang BAI Zhiyong MENG Kenta SUEKI Guixing CHEN Ruilin ZHOU School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen UniversityGuangzhou 510275China Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China RIKEN Center for Computational Science Kobe 650-0047Japan

We surveyed the occurrence of tropical cyclone(TC) tornadoes in China from 2006 to 2018. There were 64 cataloged TC tornadoes, with an average of five per year. About one-third of the landfalling TCs in China were tornadic. Consistent with previous studies, TC tornadoes preferentially formed in the afternoon shortly before and within about 36 h after landfall of the TCs. These tornadoes mainly occurred in coastal areas with relatively flat terrains. The maximum number of TC tornadoes occurred in Jiangsu and Guangdong provinces. Most of the TC tornadoes were spawned within 500 km of the TC center. Two notable characteristics were found:(1) TC tornadoes in China mainly occurred in the northeast quadrant(Earth-relative coordinates) rather than the right-front quadrant(TC motion-relative coordinates) of the parent TC circulation;and(2) most tornadoes were produced by TCs with a relatively weak intensity(tropical depressions/storms), in contrast with the United States where most tornadoes are associated with stronger TCs. Further analyses showed that TC tornadoes in China tend to be spawned in an environment with large low-level storm relative helicity and large convective available potential energy taking entrainment effects into account. TC tornadoes were particularly active in 2018, with 24 reported tornadoes accounting for 37.5% of the total surveyed samples. The first recorded tornado outbreak in the modern history of China occurred in the envelope of TC Yagi(2018), in which 11 tornadoes were reported in association with significant midlevel intrusions of dry air and the interaction of Yagi with an approaching midlatitude midlevel trough.

关键词： Tornadoes Tropical cyclones Historical statistics China

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 2015.More 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 supercells.The identified supercells were concentrated within a relatively small area in the northeast quadrant beyond 140 km from the typhoon center.These supercells were found more likely to form over flat topography and were difficult to maintain in mountainous regions.During the study period,more supercells formed offshore than onshore.The 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 level.An environmental analysis revealed that the northeast quadrant had the most favorable conditions for the genesis of supercell in this typhoon case.The nondimensional supercell composite parameter(SCP)and entraining-SCP(E-SCP)were effective in separating supercell from non-supercell environment.Even 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 development.These 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

Recent Advances in China on the Predictability of Weather and Climate

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Advances in Atmospheric Sciences 2023年第8期40卷 1521-1547页

作者： Wansuo DUAN Lichao YANG Mu MU Bin WANG Xueshun SHEN Zhiyong MENG Ruiqiang DING LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Department of Atmospheric and Oceanic Sciences/Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China CMA Earth System Modeling and Prediction Center China Meteorological AdministrationBeijing 100081China CMA Tornado Key Laboratory Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China

This article summarizes the progress made in predictability studies of weather and climate in recent years in China,with a main focus on advances in methods to study error growth dynamics and reduce uncertainties in the forecasting of weather and climate.Specifically,it covers(a)advances in methods to study weather and climate predictability dynamics,especially those in nonlinear optimal perturbation methods associated with initial errors and model errors and their applications to ensemble forecasting and target observations,(b)new data assimilation algorithms for initialization of predictions and novel assimilation approaches to neutralize the combined effects of initial and model errors for weather and climate,(c)applications of new statistical approaches to climate predictions,and(d)studies on meso-to small-scale weather system predictability dynamics.Some of the major frontiers and challenges remaining in predictability studies are addressed in this context.

关键词： predictability target observation data assimilation ensemble forecasting

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6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 Sea.During 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 weather.This 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 region.Part I primarily presents observational analyses of pre-storm environments and storm evolutions.The 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 outflows.This intersection zone(or“triple point”)is typically characterized by local enhancements of ambient vertical vorticity and convergence.Based on a rapid-scan X-band phased-array radar,finger-like echoes were recognized shortly after the gust front intruded on the triple point.Developed over the triple point,they rapidly wrapped up with a well-defined low-level mesovortex.It 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 simulations.The 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 environment.Improved knowledge of such environments provides additional guidance to assess the regional tornado risk.

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