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Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

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Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： Qi ZHONG Zhicha ZHANG Xiuping YAO Shaoyu HOU Shenming FU Yong CAO Linguo JING China meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China zhejiang meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and *** the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme *** physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting *** results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms *** reasons for this are as *** anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is ***,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved ***,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is ***,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

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 3.31%-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 *** 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

The Contribution of United States Aircraft Reconnaissance Data to the China meteorological Administration Tropical Cyclone Intensity Data:An Evaluation of Homogeneity

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Advances in Atmospheric Sciences 2024年第4期41卷 639-654页

作者： Ming YING Xiaoqin LU Shanghai Typhoon institute China Meteorological AdministrationShanghai 200030China

This paper investigates the homogeneity of United States aircraft reconnaissance data and the impact of these data on the homogeneity of the tropical cyclone(TC)best track data for the seasons 1949-1987 generated by the China meteorological Administration(CMA).The evaluation of the reconnaissance data shows that the minimum central sea level pressure(MCP)data are relatively homogeneous,whereas the maximum sustained wind(MSW)data show both overestimations and spurious abrupt *** comparisons suggest that both the reconnaissance MCP and MSW were well incorporated into the CMA TC best track *** no spurious abrupt changes were evident in the reconnaissance-related best track MCP data,two spurious changepoints were identified in the remainder of the best-track MCP ***,the influence of the reconnaissance MSWs seems to extend to the best track MSWs unrelated to reconnaissance,which might reflect the optimistic confidence in making higher estimates due to the overestimated extreme wind“observations”.In addition,the overestimation of either the reconnaissance MSWs or the best track MSWs was greater during the early decades compared to later decades,which reflects the important influence of reconnaissance data on the CMA TC best track *** wind-pressure relationship(WPR)used in the CMA TC best track dataset is also evaluated and is found to overestimate the MSW,which may lead to inhomogeneity within the dataset between the aircraft reconnaissance era and the satellite era.

关键词： tropical cyclone intensity homogeneity best track aircraft reconnaissance

Structural characteristics and drivers of greenhouse gas emissions at county-level and long-time scales:A case study of the Anji County,China

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Journal of Environmental Sciences 2024年第6期140卷 319-330页

作者： Zhouxiang Cai Liting Hu Di Chen Ying Zhang Xuekun Fang College of Environmental&Resource Sciences Zhejiang UniversityHangzhou 310058China Center for Global Change Science Massachusetts Institute of TechnologyCambridgeMA 02139United States Anji meteorological Bureau Anji 313300China

To achieve carbon neutrality,the Chinese government needs to gain a comprehensive understanding of the sources and drivers of greenhouse gas(GHG)emissions,particularly at the county *** County in eastern China is a typical example of an industrial transformation from quarrying to a low-carbon *** study analyzed the decoupling types and structural characteristics of GHG emissions and the driving factors of carbon dioxide(CO_(2))emissions in the Anji from 2006 to 2019,and explored the differences between countylevel and provincial-level or city-level *** was observed that energy-related activities are the main source of GHG emissions in Anji and that economic development is the driving factor behind the increasing CO_(2)***,industrial transformation and upgradation coupled with the alternative use of clean energy limit the growth of GHG *** study details the GHG emissions of county during the industrial transformation stage and provides corresponding policy recommendations for county governments.

关键词： County GHG emissions Decoupling Driving factors Policy recommendations

Enhancement and Removal of PM_(2.5)by Cold and Warm Air Masses Accompanying Certain Synoptic Weather Systems across Hangzhou,China during 2014-2020

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Journal of meteorological Research 2024年第3期38卷 620-634页

作者： Bu YU Feng CHEN Hanqing KANG Bin ZHU Hongnian LIU Hangzhou meteorological Bureau Hangzhou310051China Hangzhou International Urbanology Research Center for Urban Governance Studies Hangzhou311121China zhejiang institute of meteorological Sciences Hangzhou310008China Key Laboratory for Aerosol-Cloud-Precipitation of China meteorological Administration Nanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric Sciences Nanjing UniversityNanjing210023China

Local air pollution is strongly affected by synoptic weather systems,such as fronts,troughs,low-altitude vortices,or high-altitude ***,few studies have analyzed the meteorological properties of cold or warm air masses associated to these systems and their impact on local air *** this study,hourly observations of fine particulate matter(diameter of up to 2.5µm,i.e.,PM_(2.5)),wind(V),temperature(T),pressure(P),and precipitation(R),acquired in Hangzhou in 2014-2020,were *** this analysis,weather patterns were categorized into 27 types;89 and 94 cases illustrating the passage of warm and cold air masses over Hangzhou were identified,respectively;the influence of air mass temperature,wind speed,and wind direction on PM_(2.5) concentrations and local accumulation or removal was *** main results are as follows.(1)Pollution events occurred more frequently for cold than for warm air masses,but average pollutant concentration was lower for cold air masses;(2)48%of the cold air mass cases corresponded to PM_(2.5) decreases and 52%to PM_(2.5) increases,with strong cold air masses(ΔT_(24h)>4°C;∣V∣_(average)>4 m s^(−1))markedly reducing local pollution,but weak cold air masses(ΔT24h4°C)reduced the PM_(2.5) concentration whereas weaker winds(∣V∣_(average)<2 m s^(−1))increased it;and(4)PM_(2.5) concentration decreased sharply within 4 h after the passage of strong cold air masses,but more gradually within 14 h after the passage of strong warm air *** results considerably improve the current understanding of the influence of cold and warm air masses on local pollution patterns.

关键词： weather type air mass enhancement removal meteorological condition

Microphysical Insights into a Tornadic Supercell from Dual-Polarization Radar Observations in Jiangsu, China on 14 May 2021

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Journal of meteorological Research 2024年第2期38卷 303-320页

作者： Chao YUAN Yang BAI Pengfei SUN Hua BAI Lu XIA China meteorological Administration Tornado Key Laboratory Foshan 528315 institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Panjin National Climate Observatory Panjin 124010 Yangzhou meteorological Bureau of Jiangsu Province Yangzhou 225100 Yichun meteorological Bureau of Heilongjiang Province Yichun 153000

Tornadoes are incredibly powerful and destructive natural events,yet the microphysical characteristics of the parent storm and its effects on tornadogenesis remain *** study analyzed polarization radar data of a tornadic supercell that occurred in Jiangsu Province of China on 14 May 2021,in comparison with another tornadic supercell and two non-tornadic supercells that occurred in the same region in *** two tornadic supercells exhibited lower differential reflectivity(ZDR)in the hook echo region compared with the non-tornadic supercells,indicating smaller median drop sizes.A distinct increase in ZDR from the melting of frozen hydrometeors,observed between2.5-and 4.0-km altitude in the non-tornadic storms,was absent in the tornadic *** non-tornadic supercells also displayed substantially higher specific differential phase(KDP)below the melting level,likely aroused from enhanced melting and *** findings suggest fundamental microphysical contrasts between tornadic and nontornadic ***,tornadic supercells have smaller droplets and may reduce melting in hook ***,greater separation between the ZDR arc and the KDP foot was observed during *** vertical gradient of KDP related to the cooling pool strength of the hook echo,regulating rear-flank downdraft *** the limited number of cases investigated,the findings of this study indicate that monitoring ZDR,KDP,and drop size distribution trends could assist with tornado prediction and warnings.

关键词： tornado polarimetric radar supercell hook echo drop size distribution

Stable stripe and vortex solitons in two-dimensional spin-orbit coupled Bose-Einstein condensates

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Communications in Theoretical Physics 2024年第6期76卷 26-33页

作者： Yuan Guo Muhammad Idrees Ji Lin Hui-jun Li institute of Nonlinear Physics and Department of Physics Zhejiang Normal UniversityJinhua 321004China zhejiang institute of Photoelectronics and zhejiang institute for Advanced Light Source Zhejiang Normal UniversityJinhua 321004China

We present a flexible manipulation and control of solitons via Bose-Einstein *** the presence of Rashba spin-orbit coupling and repulsive interactions within a harmonic potential,our investigation reveals the numerical local solutions within the *** manipulating the strength of repulsive interactions and adjusting spin-orbit coupling while maintaining a zero-frequency rotation,diverse soliton structures emerge within the *** include plane-wave solitons,two distinct types of stripe solitons,and odd petal solitons with both single and double *** stability of these solitons is intricately dependent on the varying strength of spin-orbit ***,stripe solitons can maintain a stable existence within regions characterized by enhanced spin-orbit coupling while petal solitons are unable to sustain a stable existence under similar *** rotational frequency is introduced to the system,solitons undergo a transition from stripe solitons to a vortex array characterized by a sustained *** rotational directions of clockwise and counterclockwise are non-equivalent owing to spin-orbit *** a result,the properties of vortex solitons exhibit significant variation and are capable of maintaining a stable existence in the presence of repulsive interactions.

关键词： Bose-Einstein condensate spin-orbit coupling rotation frequency stripe solitons vortex array

Sensitivity Simulations of the 30 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 30 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)

Cholesterol-induced deformation of the gramicidin A channel inhibiting potassium ion binding and transport

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Chinese Physics B 2024年第5期33卷 696-702页

作者：肖盼曹宇朱瑾梁清 Center for Statistical and Theoretical Condensed Matter Physics & Department of Physics Zhejiang Normal UniversityJinhua 321004China zhejiang institute of Photoelectronics & zhejiang institute for Advanced Light Source Zhejiang Normal UniversityJinhua 321004China

Gramicidin A(gA)is a kind of antibiotic peptide produced by bacillus brevis and it can dimerize across lipid bilayers to form a monovalent cation *** this work,we investigate the impact of cholesterol in the lipid bilayer on the binding of potassium ions with the gA channel and the transport of the ions across the *** results indicate that cholesterol can significantly influence the conformational stability of the gA channel and cause the channel deformation which inhibits the potassium ion binding with the channel and transport across the *** work provides some molecular insights into understanding of influence of lipids on the activity of gA channel in both model membranes and plasma membranes of intact cells.

关键词： gramicidin A lipid bilayer molecular dynamics interaction