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Sensitivity Simulations of the 3. March 2020 Xichang Wildfire in Southwest China Based on the WRF-Fire Model

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Journal of Meteorological Research 2024年第4期38卷 826-843页

作者： Yujue LIU Shiguang MIAO Hanbin ZHANG institute of Urban meteorology China Meteorological AdministrationBeijing 100089 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

This paper describes a fire forecast system—Weather Research and Forecasting-Fire(WRF-Fire)—that is employed to simulate a real wildfire case in Xichang,Sichuan Province,Southwest China on 3. March 2020 at a 100-m resolution over the fire area,in order to provide a fine representation of the terrain and fuel heterogeneities and explicitly resolve the atmospheric *** sensitivity experiments were conducted to analyze the impacts of atmospheric model grid spacing and fire–atmosphere interaction on simulated meteorological fields and fire *** results indicate that finer horizontal grid spacing in the atmospheric model improves the accuracy of wind,temperature,and moisture simulations in the near surface ***,it can better describe local wind field characteristics,capture microscale wind speed fluctuations,and produce more significant effect from fire–atmosphere *** mass and energy released by the fire model and its feedback to the atmospheric model exhibit enhanced heterogeneous *** simulated fire area aligns well with the observation,with KAPPA coefficient(KC)of 0.56–0.59 and spatial correlation coefficient(SC) of 0.52–*** this real case,the influence of heterogeneous land surface on the fire behavior is much greater than the atmosphere–fire *** study suggests that WRFFire holds high potential as a real wildfire simulation tool,offering a new and feasible approach for fire prediction.

关键词： Weather Research and Forecasting-Fire wildfire coupled fire–atmosphere modeling fire behavior large-eddy simulation(LES)

Exploration of microscopic physical processes of Z-pinch by a modified electrostatic direct implicit particle-in-cell algorithm

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Chinese Physics B 2024年第9期33卷 433-442页

作者： Kaixuan Li Cheng Ning Ye Dong Chuang Xue institute of applied Physics and Computational Mathematics Beijing 100088China

For investigating efficiently the stagnation kinetic-process of Z-pinch,we develop a novel modified electrostatic implicit particle-in-cell algorithm in radial one-dimension for Z-pinch simulation in which a small-angle cumulative binary collision algorithm is *** our algorithm,the electric field in z-direction is solved by a parallel electrode-plate model,the azimuthal magnetic field is obtained by Ampere’s law,and the term for charged particle gyromotion is approximated by the cross product of the averaged velocity and magnetic *** simulation results of 2 MA deuterium plasma shell Zpinch,the mass-center implosion trajectory agrees generally with that obtained by one-dimensional MHD simulation,and the plasma current also closely aligns with the external *** phase space diagrams and radial-velocity probability distributions of ions and electrons are *** main kinetic characteristic of electron motion is thermal equilibrium and oscillation,which should be oscillated around the ions,while that of ion motion is implosion *** the region of stagnation radius,the radial-velocity probability distribution of ions transits from the non-equilibrium to equilibrium state with the current increasing,while of electrons is basically the equilibrium *** the initial ion density and current peak are not high enough,the ions may not reach their thermal equilibrium state through collisions even in its stagnation phase.

关键词： Z-pinch particle-in-cell ion heating charged particle collisions

The Spatiotemporal Distribution Characteristics of Cloud Types and Phases in the Arctic Based on CloudSat and CALIPSO Cloud Classification Products

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Advances in Atmospheric Sciences 2024年第2期41卷 310-324页

作者： Yue SUN Huiling YANG Hui XIAO Liang FENG Wei CHENG Libo ZHOU Weixi SHU Jingzhe SUN Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) and Department of Lower Atmospheric Observation Research(LAOR)Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China beijing institute of applied {3. Beijing 100029China

The cloud type product 2B-CLDCLASS-LIDAR based on CloudSat and CALIPSO from June 2006 to May 2017 is used to examine the temporal and spatial distribution characteristics and interannual variability of eight cloud types(high cloud, altostratus, altocumulus, stratus, stratocumulus, cumulus, nimbostratus, and deep convection) and three phases(ice,mixed, and water) in the Arctic. Possible reasons for the observed interannual variability are also discussed. The main conclusions are as follows:(1) More water clouds occur on the Atlantic side, and more ice clouds occur over continents.(2)The average spatial and seasonal distributions of cloud types show three patterns: high clouds and most cumuliform clouds are concentrated in low-latitude locations and peak in summer;altostratus and nimbostratus are concentrated over and around continents and are less abundant in summer;stratocumulus and stratus are concentrated near the inner Arctic and peak during spring and autumn.(3. Regional averaged interannual frequencies of ice clouds and altostratus clouds significantly decrease, while those of water clouds, altocumulus, and cumulus clouds increase significantly.(4) Significant features of the linear trends of cloud frequencies are mainly located over ocean areas.(5) The monthly water cloud frequency anomalies are positively correlated with air temperature in most of the troposphere, while those for ice clouds are negatively correlated.(6) The decrease in altostratus clouds is associated with the weakening of the Arctic front due to Arctic warming, while increased water vapor transport into the Arctic and higher atmospheric instability lead to more cumulus and altocumulus clouds.

关键词： CloudSat and CALIPSO cloud type cloud phase temporal and spatial distribution interannual variation

Impact of the Complex Terrain in beijing on Formation of Low-Level Jets

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Journal of Meteorological Research 2024年第1期38卷 138-150页

作者： Li’ao ZHOU Chenggang WANG Shiguang MIAO Ju LI School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 institute of Urban meteorology China Meteorological AdministrationBeijing 100089 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

This study investigated how the Taihang Mountains and the Yanshan Mountains affect low-level jets(LLJs)in the beijing area,based on conventional radiosonde observations from Nanjiao Observatory(2016–2017)and high-resolution Weather Research and Forecasting–Advanced Research WRF(WRF-ARW)model *** of radiosonde observations indicated that LLJs in the study area are mainly from the southwest and northwest directions,with occurrence frequency of 44.6%and 3..0%,***(northwest)LLJs are aligned parallel(perpendicular)to the orientation of the Taihang Mountain *** sensitivity experiments using the WRF-ARW model were then conducted to examine the effects of terrain forcing on the northwest and southwest LLJs,with adopted terrain heights of 100%and 50%.The results showed that for northwest LLJs,reduction in the elevation of the Taihang Mountain Range led to weakening of jet intensity by approximately 20%and reduction in jet maximum height by approximately 250 m;lowering the Yanshan Mountain Range had minor influence on the northwest LLJs,with only a 5.2%reduction in intensity and no substantial change in jet maximum *** southwest LLJs,reduction in the elevation of both the Taihang and Yanshan Mountain ranges resulted in minor changes in the intensity and height of the *** analysis revealed that the topography in the beijing area could modulate the height and intensity of the stable layer by altering the inversion structure within the boundary *** LLJs can develop rapidly within the stable layer,and both the location and the scale of the jet core exhibited reasonable agreement with the extent of the stable layer.

关键词： low-level jets(LLJs) mesoscale numerical simulation terrain forcing

Impact of Local Climate Zones on the Urban Heat and Dry Islands in beijing:Spatial Heterogeneity and Relative Contributions

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Journal of Meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang ZHENG Fu LUO Nana LI Hua GAO Yuanjian YANG institute of Urban meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83.automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate beijing

Structure of the mantle transition zone in the central and western parts of the North China Craton using the receiver function 3. Kirchhoff migration method

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Science China Earth Sciences 2024年第9期67卷 2783-2795页

作者： Min ZHU Qingju WU Jieyuan NING Ruiqing ZHANG institute of Geophysics China Earthquake AdministrationBeijing 100081China institute of Theoretical and applied Geophysics Peking UniversityBeijing 100871China

Using data from the regional broadband dense temporary array deployed by the ChinArray project,we applied the three-dimensional(3.)Kirchhoff migration method of the teleseismic P-wave receiver function to investigate discontinuity structures of the mantle transition zone(MTZ)in the central and western parts of the North China Craton(NCC)using a highresolution 3. velocity model of the East Asian *** results show that the 410-km discontinuity beneath the Datong Volcano is depressed by~10 km,indicating the presence of a high-temperature anomaly near the depth of 410 km,which is likely related to small-scale mantle upwelling caused by the dehydration of the stagnant Pacific Plate in the *** upwelling of hot material provides a heat source for surface magmatic *** the Bohai Bay Basin,significant subsidence of the 660-km discontinuity is observed,and the transition zone here is extensively ***’s suggested that the anomalies in this region are related to the stagnation of the Pacific slab in the *** the thickness of the transition zone west of the North-South Gravity Lineament appears normal,we propose that the subducting front of the Pacific slab did not cross the gravity lineament in the *** comparison,the small-scale subsidence of the 660-km discontinuity and the thickening of the MTZ observed north of the Hannuoba Volcano likely indicate that the slab crossed the gravity lineament at its turning point and remained in the ***,a local thickening of the MTZ is observed in the Dabie orogenic belt of the Qinling *** is believed to be a combined effect of lithospheric delamination into the transition zone in the lower Yangtze region and the stagnation of the Pacific Plate.

关键词： North China Craton Mantle transition zone Receiver function migration Datong Volcano

INCOMPRESSIBLE LIMIT OF IDEAL MAGNETOHYDRODYNAMICS IN A DOMAIN WITH BOUNDARIES

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Acta Mathematica Scientia 2024年第4期44卷 1441-1465页

作者： Qiangchang JU Jiawei WANG institute of applied Physics and Computational Mathematics Beijing 100088China

We study the incompressible limit of classical solutions to compressible ideal magneto-hydrodynamics in a domain with a flat *** boundary condition is characteristic and the initial data is *** first establish the uniform existence of classical solutions with respect to the Mach ***,we prove that the solutions converge to the solution of the incompressible MHD *** particular,we obtain a stronger convergence result by using the dispersion of acoustic waves in the half space.

关键词： incompressible limit ideal MHD equations boundary condition general initial data

STABLE RECOVERY OF SPARSELY CORRUPTED SIGNALS THROUGH JUSTICE PURSUIT DE-NOISING

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Journal of Computational Mathematics 2024年第1期42卷 271-288页

作者： Ningning Li Wengu Chen Huanmin Ge institute of applied Physics and Computational Mathematics Beijing 100088China beijing Sport University Beijing 100084China

This paper considers a corrupted compressed sensing problem and is devoted to recover signals that are approximately sparse in some general dictionary but corrupted by a combination of interference having a sparse representation in a second general dictionary and measurement *** provide new restricted isometry property(RIP)analysis to achieve stable recovery of sparsely corrupted signals through Justice Pursuit De-Noising(JPDN)with an additional *** main tool is to adapt a crucial sparse decomposition technique to the analysis of the Justice Pursuit *** proposed RIP condition improves the existing representative *** simulations are provided to verify the reliability of the JPDN model.

关键词： Justice Pursuit De-Noising Restricted isometry property Corrupted compressed sensing Signal recovery

Multimodel Ensemble Forecast of Global Horizontal Irradiance at PV Power Stations Based on Dynamic Variable Weight

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Journal of Tropical meteorology 2024年第3期30卷 327-336页

作者： YUAN Bin SHEN Yan-bo DENG Hua YANG Yang CHEN Qi-ying YE Dong MO Jing-yue YAO Jin-feng LIU Zong-hui Public Meteorological Service Center China Meteorological AdministrationBeijing 100081 China Key Laboratory of Energy meteorology China Meteorological AdministrationBeijing 100081 China Guangzhou institute of Tropical and Marine meteorology China Meteorological AdministrationGuangzhou 510641 China institute of Urban meteorology China Meteorological AdministrationBeijing 100089 China Center for Earth System Modeling and Prediction China Meteorological AdministrationBeijing 100081 China institute of Desert meteorology China Meteorological AdministrationUrumqi 830002 China

In the present study,multimodel ensemble forecast experiments of the global horizontal irradiance(GHI)were conducted using the dynamic variable weight *** study was based on the forecasts of four numerical models,namely,the China Meteorological Administration Wind Energy and Solar Energy Prediction System,the Mesoscale Weather Numerical Prediction System of China Meteorological Administration,the China Meteorological Administration Regional Mesoscale Numerical Prediction System-Guangdong,and the Weather Research and Forecasting Model-Solar,and observational data from four photovoltaic(PV)power stations in Yangjiang City,Guangdong *** results show that compared with those of the monthly optimal numerical model forecasts,the dynamic variable weight-based ensemble forecasts exhibited 0.97%-15.96%smaller values of the mean absolute error and 3.3.%-18.40%lower values of the root mean square error(RMSE).However,the increase in the correlation coefficient was not ***,the multimodel ensemble mainly improved the performance of GHI forecasts below 700 W m^(-2),particularly below 400 W m^(-2),with RMSE reductions as high as 7.56%-28.28%.In contrast,the RMSE increased at GHI levels above 700 W m^(-2).As for the key period of PV power station output(02:00-07:00),the accuracy of GHI forecasts could be improved by the multimodel ensemble:the multimodel ensemble could effectively decrease the daily maximum absolute error(AE max)of GHI ***,with increasing forecasting difficulty under cloudy conditions,the multimodel ensemble,which yields data closer to the actual observations,could simulate GHI fluctuations more accurately.

关键词： GHI forecast multimodel ensemble dynamic variable weight PV power station