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Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

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Advances in Atmospheric Sciences 2023年第4期40卷 711-724页

作者： Chunguang CUI Wen ZHOU Hao YANG Xiaokang WANG Yi DENG Xiaofang WANG Guirong XU Jingyu WANG institute of heavy rain China Meteorological AdministrationHubei Key Laboratory for Heavy Rain Monitoring and Warning ResearchWuhan 430205China School of Earth and Atmospheric Sciences Georgia Institute of TechnologyAtlanta 30314USA

Here,we analyze the characteristics and the formation mechanisms of low-level jets(LLJs)in the middle reaches of the Yangtze River during the 2010 mei-yu season using wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5)reanalysis *** results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs)concentrated at heights of 900-1200 *** BLJs occur most frequently at 2300 LST(LST=UTC+8 hours)but are strongest at 0200 LST,with composite wind velocities>14 m s^(-1).Synoptic-system-related LLJs(SLLJs)occur most frequently at 0800 LST but are strongest at 1100LST,with composite wind velocities>12 m s^(-1).Both BLJs and SLLJs are characterized by a southwesterly wind direction,although the wind direction of SLLJs is more westerly,and northeasterly SLLJs occur more frequently than northeasterly *** wuhan is south of the mei-yu front,the westward extension of the northwest Pacific subtropical high intensifies,and the low-pressure system in the eastern Tibetan Plateau strengthens,favoring the formation of LLJs,which are closely related to *** wind speeds on rainstorm days are greater than those on LLJ *** analysis of four typical heavy precipitation events shows the presence of LLJs at the center of the precipitation and on its southern side before the onset of heavy *** were shown to develop earlier than SLLJs.

关键词： mei-yu front boundary layer jets synoptic low-level jets heavy rainfall middle reaches of the Yangtze River

SATELLITE-BASED ANALYSIS ON THE CONCENTRIC EYEWALL REPLACEMENT CYCLES OF SUPER TYPHOON MUIFA (1109)

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Journal of Tropical Meteorology 2016年第3期22卷 330-340页

作者：朱雪松余晖毛卓成徐明谈建国 Shanghai institute of Meteorological Science Shanghai 200030 China Shanghai Typhoon institute/cma Shanghai 200030 China Shanghai Urban Environment Meteorology Center Shanghai 200135 China institute of heavy rain/cma Wuhan 430074 China

Multisatellite data is used to analyze the characteristics of three eyewall replacement cycles(ERCs) during the lifetime of Typhoon Muifa(1109).Spiral rainbands evolutions,concentric eyewall(CE) structure modes,CE durations,and intensity changes are discussed in *** addition,an ERC evolution model of Typhoon Muifa is *** are four main findings.(1) The outer spiral rainband joins end to end to form the outer eyewall after it disconnects from the original(inner) *** inner eyewall weakens as the outer eyewall becomes axisymmetric and is *** contraction of the outer eyewall causes the inner eyewall to dissipate ***,the ERC ends with an annular eyewall or spiral rainbands.(2) Although the CE duration times of Typhoon Muifa's three ERCs covered a large range,the CE structures were all maintained for approximately 5 h from the formation of the axisymmetric outer eyewall to the end of the cycle.(3) There is no obvious precipitation reflectivity in the eye or moat region for the subsidence *** convection within the two eyewalls is organized as a radially outward slope with increasing height.(4) Typhoon intensity estimation results based on ADT may not explain the intensity variations associated with ERC correctly,while the typhoon's warm core data retrieved from AMSU-A works well.

关键词： satellite data super typhoon concentric eyewall eyewall replacement cycle intensity variations

Characteristics of super drought in Southwest China and the associated compounding effect of multiscalar anomalies

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Science China Earth Sciences 2024年第7期67卷 2084-2102页

作者： Lin WANG Wen CHEN Gang HAUNG Ting WANG Qiulin WANG Xiaoyun SU Zixuan REN Chakrit CHOTAMONSAK Atsamon LIMSAKUL Kritanai TORSRI CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China heavy rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Chengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650500China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Hangzhou Meteorological Bureau Hangzhou 310051China Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Geography Faculty of Social SciencesChiang Mai UniversityChiang Mai 50200Thailand Environmental Science Research Center Faculty of ScienceChiang Mai UniversityChiang Mai 50200Thailand Climate Change and Environmental Research Center TechnopolisKlong 5Klong LuangPathumthani 12120Thailand Hydro-Informatics Innovation Division Hydro-Informatics InstituteMinistry of Higher EducationScienceResearch and InnovationBangkok 10900Thailand

In recent decades,Southwest China(SWC)has suffered from frequent super droughts,leading to severe economic losses and ecological *** study investigates the characteristics of super droughts in SWC during 1961-2022,reveals the compounding effect of multiscalar anomalies,and explores the plausible atmospheric circulation mechanisms *** nature of super drought is a compound drought caused by the superposition of extreme drought events across multiple time *** contrasting the typical drought cases in 2006 and 2022,the decisive role of multiscalar drought compounding is *** on the Comprehensive Multiscalar Index(CMI),multiple super drought events in SWC were identified to be temporally clustered during *** them,the decadal background of enhanced evaporation and precipitation deficit at long time scales is a necessary condition for shaping the overall pattern of super droughts,while the precipitation and evaporation anomalies at short time scales trigger the outbreak of super droughts,determining the exact timing of *** events include August-September 2006,November 2009 to May 2010,July-October 2011,April-May 2012,January-April 2013,*** results suggest that the contribution of superposed precipitation anomalies to super drought is 2.4 times that of *** regards the circulation mechanisms affecting multiscalar precipitation,the anomalous spatial patterns at short-term and long-term scales are similar,featuring the cyclonic circulation over the South China Sea and the northeasterly wind anomalies together with the subsidence center over *** 2006-2014,the possible causes for the cross-seasonal persistent precipitation reduction in SWC are the extreme negative phase of the Pacific Decadal Oscillation(PDO)in the North Pacific as well as the pronounced warming of the warm pool in the western *** key dynamic processes are outlined as *** the one hand,the negative PDO p

关键词： Super drought Multiscalar Compounding effect Mechanism analysis Southwest China

AN INTEGRATION METHOD WITH FITTING CUBIC SPLINE FUNCTIONS TO A NUMERICAL MODEL OF 2ND-ORDER SPACE-TIME DIFFERENTIAL REMAINDER——FOR AN IDEAL GLOBAL SIMULATION CASE WITH PRIMITIVE ATMOSPHERIC EQUATIONS

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Journal of Tropical Meteorology 2013年第4期19卷 388-396页

作者：辜旭赞张兵王明欢 Hubei Key Laboratory for heavy rain Monitoring and Warning Research Institute of Heavy Rain China Meteorological Administration

In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series *** we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline *** the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical *** is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order ***"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original *** addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable ***,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic *** the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,***,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-

关键词： numerical forecast and numerical simulation 2nd-order space-time differential remainder numerical model cubic spline functions Navier-Stokes primitive equations quasi-Lagrangian time-split integration scheme global simulation case

NUMERICAL EXPERIMENTS FOR THE EFFECTS OF TWO MODEL INITIALIZATION SCHEMES ON rainFALL FORECAST IN THE 2008 FLOODING SEASON

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Journal of Tropical Meteorology 2014年第3期20卷 251-266页

作者：王叶红彭菊香赵玉春 Hubei Key Laboratory for heavy rain Monitoring and Warning Research Institute of Heavy Rain China Meteorological Administration

In this paper, based on heavy rain numerical forecast model AREM(Advanced Regional Eta Model), two different initialization schemes, LAPS and GRAPES-3DVAR, are used to run assimilation experiments of AREM-LAPS and AREM-3DVAR with the same data source(NCEP forecast field, surface data and radio-soundings) during the period from 21 May to 30 July 2008 to investigate the effect of the two initialization schemes on the rainfall simulation. The result suggests that:(1) the forecast TS score by the AREM-LAPS is higher than that by the AREM-3DVAR for rainfall in different areas, at different valid time and with different intensity, especially for the heavy rain, rainstorm and extremely heavy rain;(2) the AREM-3DVAR can generally simulate the average rainfall distribution, but the forecast area is smaller and rainfall intensity is weaker than the observation, while the AREM-LAPS significantly improves the forecast;(3) the AREM-LAPS gives a better forecast for the south-north shift of rainfall bands and the rainfall intensity variation than the AREM-3DVAR;(4) the AREM-LAPS can give a better reproduction for the daily change in the mean-rainfall-rate of the main rain band, and rainfall intensity changes in the eastern part of Southwest China, the coastal area in South China, the middle-lower valleys of Yangtze river, the Valleys of Huaihe river, and Shandong peninsula, with the rainfall intensity roughly close to the observation, while the rainfall intensity simulated by the AREM-3DVAR is clearly weaker than the observation, especially in the eastern part of Southwest China; and(5) the comparison verification between the AREM-LAPS and AREM-3DVAR for more than 10 typical rainfall processes in the summer of 2008 indicates that the AREM-LAPS gives a much better forecast than AREM-3DVAR in rain-band area, rainfall location and intensity, and in particular, the rainfall intensity forecast is improved obviously.

关键词： weather forecast precipitation characteristics numerical experiment flooding-season rainfall LAPS system GRAPES-3DVAR system AREM model

Warm-Season Diurnal Variations of Total, Stratiform, Convective, and Extreme Hourly Precipitation over Central and Eastern China

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Advances in Atmospheric Sciences 2019年第2期36卷 143-159页

作者： Yongguang ZHENG Yanduo GONG Jiong CHEN Fuyou TIAN National Meteorological Centre Chinese Academy of Meteorological Sciences wuhan institute of heavy rain of China Meteorological Administration Heilongjiang Meteorological Office

Diurnal variations in amount, frequency and intensity of warm-season hourly precipitation(HP) at seven levels, which are defined as HP 0.1, 0.5, 1, 5, 10, 20 and 50 mm, are revealed based on no less than 30 years of hourly rain-gauge observations at national stations over central and eastern China(CEC). This study investigates the variations, relationships, differences and similarities of total, stratiform, convective and extreme HP over the entire CEC and various subregions. Results indicate that the variations in the amount and frequency of HP at the seven levels over the entire CEC all display a bimodal feature. For various regions, the variations of total HP mostly feature two peaks, while convective HP mainly occurs in the late afternoon and determines the diurnal variation of total HP intensity. On the basis of the primary peak time periods of HP frequency at all levels over different subregions, the variations can be classified into three main categories: late-afternoon primary peak, nocturnal primary peak, and time-shifting primary peak. However, the variations over some coastal regions like the Liaodong Peninsula, the Shandong Peninsula, and the coastal regions of Guangdong, distinctly differ from those over their corresponding larger regions. Overall, the normalized diurnal variation amplitude of amount and frequency increases with the increasing HP intensity; convective precipitation can be represented by HP 10 mm; and the intensity of HP 50 mm is slightly larger during the nighttime than during the daytime over the entire CEC. In northern China, diurnal variation in HP 5 mm can represent well that in convective precipitation.

关键词： diurnal variation total precipitation stratiform precipitation convective precipitation extreme precipitation

A Study on Water Vapor Transport and Budget of heavy rain in Northeast China

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Advances in Atmospheric Sciences 2010年第6期27卷 1399-1414页

作者：孙力沈柏竹隋波 institute of Meteorological Sciences of Jilin Province wuhan institute of heavy rain Laboratory of Research for Middle-High Latitude Circulation Systems and East Asian Monsoon

The characteristics of moisture transport and budget of widespread heavy rain and local heavy rain events in Northeast China are studied using the NCEP-NCAR reanalysis 6-hourly and daily data and daily precipitation data of 200 stations in Northeast China from 1961-2005. The results demonstrate that during periods with widespread heavy rain in Northeast China, the Asian monsoon is very active and the monsoonal northward moisture transport is strengthened significantly. The widespread heavy rainfall obtains enhanced water vapor supply from large regions where the water vapor mainly originates from the Asian monsoon areas, which include the East Asian subtropical monsoon area, the South China Sea, and the southeast and southwest tropical monsoon regions. There are several branches of monsoonal moisture current converging on East China and its coastal areas, where they are strengthened and then continue northward into Northeast China. Thus, the enhanced northward monsoonal moisture transport is the key to the widespread heavy rain in Northeast China. In contrast, local heavy rainfall in Northeast China derives water vapor from limited areas, transported by the westerlies. Local evaporation also plays an important role in the water vapor supply and local recycling process of moisture. In short, the widespread heavy rains of Northeast China are mainly caused by water vapor advection brought by the Asian monsoon, whereas local heavy rainfall is mainly caused by the convergence of the westerly wind field.

关键词： heavy rain Northeast China moisture transport moisture budget Asian monsoon

Phase Two of the Integrative Monsoon Frontal rainfall Experiment(IMFRE-II)over the Middle and Lower Reaches of the Yangtze River in 2020

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Advances in Atmospheric Sciences 2021年第3期38卷 346-356页

作者： Chunguang CUI Xiquan DONG Bin WANG Hao YANG Hubei Key Laboratory for heavy rain Monitoring and Warning Research Institute of Heavy RainChina Meteorological AdministrationWuhan 430205China Department of Hydrology and Atmospheric Sciences University of ArizonaTucsonArizona 85721-0011USA

Phase Two of the Integrative Monsoon Frontal rainfall Experiment(IMFRE-II)was conducted over the middle and lower reaches of the Yangtze River during the period 16 June to 19 July *** paper provides a brief overview of the IMFRE-II field campaign,including the multiple ground-based remote sensors,aircraft probes,and their corresponding measurements during the 2020 mei-yu period,as well as how to use these numerous datasets to answer scientific *** highlights of IMFRE-II are:(1)to the best of our knowledge,IMFRE-II is the first field campaign in China to use ground-based,airborne,and spaceborne platforms to conduct comprehensive observations over the middle and lower reaches of the Yangtze River;and(2)seven aircraft flights were successfully carried out,and the spectra of ice particles,cloud droplets,and raindrops at different altitudes were *** in-situ measurements will provide a“cloud truth”to validate the ground-based and satellite-retrieved cloud and precipitation properties and quantitatively estimate their retrieval *** are also crucial for the development of a warm(and/or cold)rain conceptual model in order to better understand the cloud-to-rain conversion and accretion processes in mei-yu precipitation *** an integrative analysis of ground-based,aircraft,and satellite observations and model simulations,we can significantly improve our cloud and precipitation retrieval algorithms,investigate the microphysical properties of cloud and precipitation,understand in-depth the formation and dissipation mechanisms of mei-yu frontal systems,and improve cloud microphysics parameterization schemes and model simulations.

关键词： 2020 mei-yu frontal systems IMFRE-II and its highlights Comprehensive observations from groundbased airborne and spaceborne platforms

The Evolutionary Modeling and Short-range Climatic Prediction for Meteorological Element Time Series

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Acta meteorologica Sinica 2005年第3期19卷 375-380页

作者：俞康庆周月华杨荆安康卓 institute of heavy rain China Meteorological Administration Computation Center Wuhan University

The time series of precipitation in flood season (May-September) at wuhanStation, which is set as an example of the kind of time series with chaos characters, is split intotwo parts: One includes macro climatic timescale period waves that are affected by some relativelysteady climatic factors such as astronomical factors (sunspot, etc.), some other known and/orunknown factors, and the other includes micro climatic timescale period waves superimposed on themacro one. The evolutionary modeling (EM), which develops from genetic programming (GP), is supposedto be adept at simulating the former part because it creates the nonlinear ordinary differentialequation (NODE) based upon the data series. The natural fractals (NF) are used to simulate thelatter part. The final prediction is the sum of results from both methods, thus the model canreflect multi-time scale effects of forcing factors in the climate system. The results of thisexample for 2002 and 2003 are satisfactory for climatic prediction operation. The NODE can suggestthat the data vary with time, which is beneficial to think over short-range climatic analysis andprediction. Comparison in principle between evolutionary modeling and linear modeling indicates thatthe evolutionary one is a better way to simulate the complex time series with nonlinearcharacteristics.

关键词： time series evolutionary modeling short-range climatic prediction