Internal Dynamical Processes Research Articles

Interannual ENSO diversity, transitions, and projected changes in observations and climate models

Abstract Diverse characteristics of El Niño Southern Oscillation (ENSO) events challenge the traditional view of tropical coupled ocean-atmosphere systems. The probability of a transition from one type of event to another is influenced by multiple factors of which many are projected to change. Here we assess the likelihood of ENSO transitions in observations and climate models, including a distinction between events that peak in the Eastern Pacific (EP) and Central Pacific (CP). We find that the initial ENSO state influences the likelihood of certain transitions and that some transitions are not physically possible or stochastically likely. For example, transitions to CP events are more likely than EP events except from a neutral state. We also find that El Niños tend to occur as singular events compared to La Niñas. While consecutive El Niño and La Niña events of EP type are possible, opposing EP events do not occur in succession. We identify several transitions likely driven by internal dynamical processes including neutral conditions to El Niño, CP El Niño to another El Niño, EP El Niño to CP La Niña, CP La Niña to CP El Niño and La Niña, and EP La Niña to neutral and CP El Niño. Projections of future transitions show an increased probability of transitions to CP El Niño events while transitions to EP La Niña events become less frequent under a high-emissions scenario. Accordingly, transitions to these events become more and less likely, respectively. We also find changes in the likelihood of specific transitions in a warming world: consecutive CP El Niño events become more likely while EP El Niño events become less likely to transition into CP La Niña events. These changes are expected to occur as early as 2050 with some changes to be accelerated by the end of the 21st century.

Nation brand: A systems approach to the creation and management

A nation brand impacts on a country’s economic development, stimulating or, contrarily, limiting people and organisations’ readiness to invest various resources within a particular jurisdiction. Simultaneously, a nation brand originates in all activities of organisations operating in the country’s territory. The paper aims to develop theoretical foundations of the nation brand management as a system. The methodological basis of the study is the concept of nation branding and the systems approach. A set of general scientific methods of analysis, synthesis, systematisation and generalisation are used. As a result, the paper provides and describes a system for the nation brand management that comprises input (existing perception of a country), transformation processes (creation of an image), and output (the image shaped). The value of the developed system lies in its ability to coordinate the interests of diverse stakeholders. The article presents a vision of 7-S model implementation for the nation brand based on the understanding of the relationships that lead to the formation of nation brand as well as the representation of external and internal dynamic processes that evolve over time, etc. The findings contribute to grasping the essence of the nation brand management using the principles of the systems approach, which potentially enhances the country’s economic development.

A case study on more recent heat wave occurred in South Africa, based on background weather synoptic and dynamic characteristics analysis

This study investigates the characteristics of the more recent heat wave episode in South Africa during January 2023. The evaluation of several meteorological parameters using different reanalysis models and observational datasets have demonstrated that the domination of the anticyclonic pattern over the study area associated with a omega-blocking high. The dominant subtropical Botswana subtropical high along with the low-level omega blocking high pressure over South Africa is one of the main factors for the abnormally hot weather event. The upper-level anomaly wind analysis illustrates the weakening of the zonal wind accompanied by the Rossby waves meridionally stretching. Also, this is correlated to abnormal both tropical easterly and southern westerly jets meandering around an omega-blocking pattern weather system over South Africa which causes warm air mass trapping over the study region. The outcome model results prove the anomalies of the surface higher temperature happened close to the center of the blocking high, where an intensified southward shift of the easterly tropical jet along with the northward shift (jet entrance) of an intensified westerly jet formed two strong cores creating confluent. This research also shows that the January heat wave is demonstrated by an anomalous upper tropospheric anticyclonic inflow (southern hemisphere) causing the strong subsidence, resulting in the surface temperature increase. In comparison with the heat wave event in January 2016, the current study displays the high impact of the internal and local dynamical processes. Also, the current case study addressed in drier condition with less health risk than the previous case study noticed in 2016.

Methane emission from a cool brown dwarf

Beyond our Solar System, aurorae have been inferred from radio observations of isolated brown dwarfs1,2. Within our Solar System, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for corresponding infrared features, but only null detections have been reported3. CWISEP J193518.59-154620.3. (W1935 for short) is an isolated brown dwarf with a temperature of approximately 482 K. Here we report James Webb Space Telescope observations of strong methane emission from W1935 at 3.326 μm. Atmospheric modelling leads us to conclude that a temperature inversion of approximately 300 K centred at 1–10 mbar replicates the feature. This represents an atmospheric temperature inversion for a Jupiter-like atmosphere without irradiation from a host star. A plausible explanation for the strong inversion is heating by auroral processes, although other internal and external dynamical processes cannot be ruled out. The best-fitting model rules out the contribution of H3+ emission, which is prominent in Solar System gas giants. However, this is consistent with rapid destruction of H3+ at the higher pressure where the W1935 emission originates4.

Developmental mechanism of the SWCV nonlinear inertial waves

Based on the Boussinosq Approximation formulas in the symmetric, cylindric coordinates, the nonlinear effects of the internal inertial gravity waves on the meso-micro scale convective activities of Southwest China Vortex system are analyzed by the multi-scale and perturbation approximation methods. The results obtain two main conclusions: (1) When the atmospheric stratification is stable, the inertial gravity waves for Southwest China Vortex may also develop into finite-amplitude wave packet with a solitonic characteristics of large amplitude and short duration, forming a long-narrow wave band which activates and organizes severe convective activities like high wind and thunderstorm of Southwest China Vortex. When the atmospheric stratification is unstable, the inertial gravity waves exhibits attenuating oscillation characteristics and develops into finite-amplitude wave packet with large amplitude and fast speed, forming queue-type wave band that activates and organizes extreme weather like persistent heavy rainfall of Southwest China Vortex. (2) Under different atmospheric stratifications, the effects of thermal forcing on the inertial gravity waves for Southwest China Vortex are different. In the stable atmospheric stratification, the thermal forcing mainly intensifies the inertial gravity waves and has no significant effect on its duration. And in the unstable atmospheric stratification, the thermal forcing not only strengthens its growth but also obviously extends its duration. The research has revealed the some nonlinear characteristics of the internal inertial gravity waves for Southwest China Vortex, and improved the theoretical understanding about the critical role of the internal inertial gravity waves dynamic processes and its influence mechanism on the meso-micro scale severe convection weather for Southwest China Vortex.

Atlantic blocking events in a simplified nonlinear baroclinic model for local finite-amplitude wave activity

To better understand the mechanisms underlying the formation of blocking highs over the North Atlantic as a type of large-amplitude disturbance, this paper reports results from numerical experiments within the framework of local finite-amplitude wave activity (LWA). The numerical model employed in this study explicitly depicts two important atmospheric internal dynamic processes—nonlinear zonal eddy flux and Rossby wave packet propagation—which have been individually emphasized by different previous studies. The simulation results reveal that these two dynamic processes are the dominant contributors to the formation of Atlantic blocking cases. However, they exert different influences over different regions. The southern and northern parts of the primary LWA associated with the blocking cases are mainly induced by the nonlinear zonal eddy flux and Rossby wave packet propagation, respectively. Thus, this study reconciles and integrates insights from previous studies on Atlantic blocking events, providing a cohesive understanding of their formation.摘要为研究北大西洋阻高的形成机制, 本文在局部有限振幅波活动 (LWA) 框架下进行了一系列数值实验. 采用的数值模型能显式地描绘出两种重要的大气内部动力过程, 即非线性纬向位涡通量和Rossby波包传播. 模拟结果显示, 这两种动力学过程均是形成大西洋阻高的重要机理. 具体地, 非线性纬向位涡通量和Rossby波包传播, 分别是大西洋阻高南部和北部LWA形成的主导因子. 因此, 本研究综合了前人关于大西洋阻高的研究成果, 为其形成机理提供了新的认识.

DYNAMIC PROCESSES OF A HAND-HELD MOTORIZED MOWER DURING THE START OF THE MOWING PROCESS

From the point of view of revitalization of agrarian processes in our country, the perspective of its development showed us that animal husbandry remains one of the priority sectors, which is due to the production of animal husbandry products. Based on this, the problem of producing rough feed for mining conditions remains a problematic issue in small farms and peasant farms, where it is impossible to use large-capacity machines and food production is still done manually. The purpose of the research is the methodology of calculating the internal dynamic processes of a small power hand motorized rotary mower during the start of the mowing work process. The scientific paper presents the dynamic load of a small power hand motorized mower at the moment of starting mowing, which is highly dependent on the work of the working body, so as to perform the mowing process with quality and less losses.

Early evolution and three-dimensional structure of embedded star clusters

ABSTRACT We perform simulations of star cluster formation to investigate the morphological evolution of embedded star clusters in the earliest stages of their evolution. We conduct our simulations with Torch, which uses the Amuse framework to couple state-of-the-art stellar dynamics to star formation, radiation, stellar winds, and hydrodynamics in Flash. We simulate a suite of 104 M⊙ clouds at 0.0683 pc resolution for ∼2 Myr after the onset of star formation, with virial parameters α = 0.8, 2.0, 4.0 and different random samplings of the stellar initial mass function and prescriptions for primordial binaries. Our simulations result in a population of embedded clusters with realistic morphologies (sizes, densities, and ellipticities) that reproduce the known trend of clouds with higher initial α having lower star formation efficiencies. Our key results are as follows: (1) Cluster mass growth is not monotonic, and clusters can lose up to half of their mass while they are embedded. (2) Cluster morphology is not correlated with cluster mass and changes over ∼0.01 Myr time-scales. (3) The morphology of an embedded cluster is not indicative of its long-term evolution but only of its recent history: radius and ellipticity increase sharply when a cluster accretes stars. (4) The dynamical evolution of very young embedded clusters with masses ≲1000 M⊙ is dominated by the overall gravitational potential of the star-forming region rather than by internal dynamical processes such as two- or few-body relaxation.

Great balls of FIRE II: The evolution and destruction of star clusters across cosmic time in a Milky Way-mass galaxy

ABSTRACT The current generation of galaxy simulations can resolve individual giant molecular clouds, the progenitors of dense star clusters. But the evolutionary fate of these young massive clusters, and whether they can become the old globular clusters (GCs) observed in many galaxies, is determined by a complex interplay of internal dynamical processes and external galactic effects. We present the first star-by-star N-body models of massive (N ∼ 105–107) star clusters formed in a FIRE-2 MHD simulation of a Milky Way-mass galaxy, with the relevant initial conditions and tidal forces extracted from the cosmological simulation. We select 895 (∼30 per cent) of the YMCs with >6 × 104 M⊙ from Grudić et al. 2022 and integrate them to z = 0 using the cluster Monte Carlo code, CMC. This procedure predicts a MW-like system with 148 GCs, predominantly formed during the early, bursty mode of star formation. Our GCs are younger, less massive, and more core-collapsed than clusters in the Milky Way or M31. This results from the assembly history and age-metallicity relationship of the host galaxy: Younger clusters are preferentially born in stronger tidal fields and initially retain fewer stellar-mass black holes, causing them to lose mass faster and reach core collapse sooner than older GCs. Our results suggest that the masses and core/half-light radii of GCs are shaped not only by internal dynamical processes, but also by the specific evolutionary history of their host galaxies. These results emphasize that N-body studies with realistic stellar physics are crucial to understanding the evolution and present-day properties of GC systems.

Review on the Influence of Complex Stratum on the Drilling Trajectory of the Drilling Robot

A complex stratum formed due to the influence of internal and external dynamic geological processes will lead to extremely complex mining conditions in deep exploration and development of oil, gas, coal and other resources, processes mainly threatened by disasters such as coal and gas conflict, mine water inrush, and rock burst. Combined with formation identification and measurement while drilling technology, the drilling level of underground drilling robot in coal mines is constantly developing. In order to prevent coal mine accidents and achieve safe and efficient mining, efficient and accurate drilling is the key, and should be based on research on the influence of complex stratum on the drilling trajectory. In order to comprehensively and systematically summarize the research on the influence of a complex stratum on drilling tool mechanics, this paper describes the history and current situation of complex stratum exploration, measurement while drilling technology, borehole bending conditions, stress analysis of complex coal seams on drilling tools, formation force theory and method, and geosteering drilling technology. In addition, the research and application of directional drilling technology in gas control, water hazard prevention and geological anomaly detection are also discussed.

Multiple fabrics in the Tavares pluton (NE Brazil): Insights on the interplay between emplacement mechanism, internal magmatic processes, and tectonic deformation

Internal dynamic processes and contemporaneous deformation may produce multiple magmatic fabrics and structures during the crystallization of granitic plutons. Here we report the case of the Tavares pluton (Borborema Province, northeastern Brazil), a ∼160 km2 NE-SW elongate pluton bounded in the north and southeast by dextral and sinistral shear zones, respectively. A remarkable feature of this pluton is the occurrence of numerous elliptical flow-related structures delineated by mafic schlieren resulting from the interaction of dioritic and granitic melts. We analyzed airborne geophysical data, conducted a field and anisotropy of magnetic susceptibility (AMS) study at the pluton scale, and detailed the magnetic fabric of two elliptical structures. The pluton has a well-developed magmatic foliation defined by the shape preferred orientation of K-feldspar megacrysts and planar concentrations of mafic minerals. The foliation trajectories are concentric and inwardly dipping, indicating a lopolith shape for the pluton. NE-trending magmatic shear zones and faults attest to sinistral shearing before complete crystallization. The dominant AMS fabric at pluton scale, represented by NE-to NNE-trending magnetic foliations with steep dips associated with lineations of moderate to shallow plunges, is consistent with the sinistral strain regime. In contrast, the magnetic foliation and lineation in the two elliptical structures dip moderately to the east, with the magnetic foliation commonly transecting the orientation of the mafic schlieren. We relate this latter fabric to regional contraction, characterized by top-to-the-west tectonic transport in the country rocks, during pluton construction. We propose that (i) tectonic overpressure due to regional compression assisted progressive pluton inflation by floor subsidence, generating the concentric magmatic fabric, and (ii) a small component of noncoaxial shear during bulk contraction led to sinistral shearing in the late stages of crystallization. We found no evidence for shear zone-controlled pluton emplacement. Instead, (i) the SE-bounding sinistral shear zone is restricted to the pluton vicinity, suggesting nucleation due to thermal softening of country rocks by the pluton, and (ii) magmatic foliations and lineations that could be related to the N-bounding dextral shear zone are absent. Also, the available geochronological data suggest that emplacement of the Tavares pluton predated by several tens of millions of years the intrusion of well-documented syn-transcurrence plutons in the Borborema Province. Therefore, the spatial association of the Tavares pluton with strike-slip shear zones is not strong enough evidence to assume a shear zone control on pluton emplacement.

Spatial distribution analysis and application of engineering disturbance disasters in the Himalayan alpine valley

The Himalayan alpine canyon area is characterized by complex engineering geological conditions and abnormal internal and external dynamic geological processes. Severe slope disturbance disasters can be caused by engineering disturbances. In this study, field investigations and theoretical analyses were performed to determine the formation mechanism, spatial distribution law, and controlling factors of engineering disturbance disasters in the Himalayan alpine and canyon areas. A total of 396 engineering disturbance disasters were identified within the scope of the 2,800-km survey line. A geographic information system and mathematical statistical analysis were used to analyze the correlation between engineering disturbance disasters and factors such as the slope, slope aspect, elevation, peak ground acceleration, distance from fault, distance from river, rainfall, lithological changes, and historical earthquake effects. The statistical analysis indicates a good power-law and exponential distribution between the engineering disturbance disaster concentration and the slope and distance from the river, respectively. The slope and distance from the river are the two most important factors in determining the spatial distribution of engineering disturbance disasters; the other factors also influence the distribution to some extent. These factors affect the quality of the slope rock and soil mass, affecting slope stability. The main form of engineering disturbance in the study area is slope cutting. The direct result (increase in slope) and secondary result (decrease in rock mass quality caused by unloading rebound) of slope cutting are the most important factors inducing engineering disturbance disasters. Based on previous research results, factors in engineering disturbance disasters in alpine and canyon areas were evaluated, and the distribution of disturbance disasters along the China–Nepal Railway was predicted. The study area was divided into extremely high-(13.6%), high-(30.4%), medium-(34.1%), and low-susceptibility (22.0%) areas. The research results can provide a theoretical basis for prevention and treatment of engineering disturbance disasters in Himalayan alpine valley areas.

A novel approach of multi-hazard integrated zonation on the ancient Silk Road

Hazard identification is crucial for disaster risk reduction in areas featuring multiple co-occurring hazards and active internal and external dynamic geographical processes. Coupling the elements of external hazard-forming environments and the internal mechanisms inducing hazards, a novel multi-hazard integration zonation (MIZ) method has been developed in which a segmented multi-hazard identification function was constructed to identify the dominant hazard types and their boundaries in a region. Taking the ancient Silk Road as a case study, the major types and spatial zonation of multiple hazards have been identified, which are in accordance with the actual disaster situation. These sympatric multiple hazards present a widely spatial scattered distribution of individual hazards and a more concentrated distribution of multiple hazards in the ancient Silk Road area. These results, combined with the geomorphological features and the climatic zones of the analyzed area, reveal the spatial boundaries among these major hazards at the macro- and microscales. These findings suggest that the proposed MIZ methodology can provide scientific support for rational engineering layouts and regional planning and may serve as pertinent guidance for multi-hazard identification in ancient Silk Road area and beyond.

Why was South China extremely wet during January–February 2022 despite La Niña?

The boreal winter climate of 2022 was characterized by the occurrence of La Niña, which is one of the most predictable drivers of South China precipitation (SCP) deficit. However, surprisingly, South China (SC) received abnormal high precipitation in January–February (JF) 2022. Possible causes of the deviation of JF 2022 SCP from its historical response to La Niña are explored with observational and reanalysis data. Results suggest that the La Niña event in winter 2022 features an eastern Pacific (EP) type, which corresponds to a weaker zonal sea surface temperature (SST) gradient between the equatorial central and western Pacific than those of the historical La Niña events, leading to a weaker western North Pacific (WNP) cyclone (WNPC) anomaly. Meanwhile, the SST warming over the tropical Indian Ocean (TIO) would also weaken the La Niña-associated WNP circulation anomaly. Therefore, the flavor of La Niña and the TIO warming act in concert to dampen the La Niña-associated WNPC anomaly and the SCP deficit. But these tropical SST anomalies are still insufficient to explain the extremely high SCP. Furthermore, the investigation identifies two extra-tropical circulation patterns over Eurasia that dominate the SCP anomalies in JF 2022. One is the wave train propagating along the South Asian jet that intensifies the India–Burma trough. It enhances the SCP through exciting anomalous strong moisture transport from the Bay of Bengal and ascending motion. The other is the positive geopotential height anomaly over eastern Siberia that prompts southward cold air intrusion and convergence over the SC region. These two dynamical drivers can account for approximately 75% of the observed SCP anomaly in JF 2022. However, they may be largely attributed to the atmospheric internal dynamical processes, which implies limited seasonal predictability of this extreme wet event.

Dynamic Investigation of Battery Materials via Advanced Visualization: From Particle, Electrode to Cell Level.

Li-ion batteries, the most-popular secondary battery, are typically electrochemical systems controlled by ion-insertion dynamics. The battery dynamics involve mass transport, charge transfer, ion-electron coupled reactions, electrolyte penetration, ion solvation, and interfacial evolution. However, it is difficult for the traditional electrochemical methods to capture the accurate and individual details of the dynamic processes in "black box" batteries; instead, only the net result of multi-factors on the whole scale. Recently, different advanced visualization techniques have been developed, which provide powerful tools to track and monitor the internal real-time dynamic processes, giving intuitive details and fine information at various scales from crystal lattice, single particle, electrode to cell level. Here, the recent progress on the investigation of electrochemical dynamics in battery materials are reviewed, via developed techniques across wide timescales and space-scales, including the dynamic process inside the active particle, kinetics issues at the electrode/electrolyte interface, dynamic inhomogeneity in the electrode, and dynamic transportation at the cell level. Finally, the fundamental principles to improve the battery dynamics are summarized and new technologies for future more stringent conditions are highlighted. In prospect, this review opens sight on the battery interior for a clearer, deeper, and more thorough understanding of the dynamics.

Seismic Contributions to Secular Changes in Global Geodynamic Parameters

AbstractSecular changes in global geodynamic parameters (polar motion excitation, length of day, and J2, etc.) are significant to understand internal mass transport in the solid Earth system and surface geophysical fluids related to global climate. However, the glacial isostatic adjustment (GIA) and climate‐driven surface mass redistribution are insufficient to explain the origin. We are motivated to report the significance of seismic effect in the pursuit of understanding the budget of secular changes in geodynamic parameters. The seismic effect is comparable to the GIA effect and amounts to 20% or larger (up to 30%) of the observed secular changes in global geodynamic parameters. Therefore, the seismic effect must be treated as one key mechanism of driving secular changes in geodynamic parameters, which is critical to invert rheological structure, clarify internal dynamic processes, and reveal the physical evolution of the Earth.

Thermodynamic Characteristics of a Single Stage Pneumatically Driven Gifford–McMahon Refrigerator

Abstract At present, the demand for high cooling capacity Gifford–McMahon (GM) refrigerators is increasing to cool the high-temperature superconducting magnets in cryogenic temperature range. Therefore, it is necessary to enhance the cooling capacity of existing refrigerators, which needs a thorough understanding of related thermodynamic phenomena. In this paper, thermodynamic processes of a GM refrigerator are analyzed and its performance is compared with Carnot cycle, and Brayton cycle with and without work recovery. Subsequently, a mathematical model has been formulated for a pneumatically driven GM refrigerator by applying the fundamental principles of thermodynamics and mechanics. The model computes the influence of geometrical and operating parameters upon its refrigeration performance. Subsequently, the impact of valve opening intervals upon internal thermodynamic and dynamic processes is evaluated. The dynamic characteristics of the displacer motion, transient variation of mass flow, and pressure distribution are studied by the model for different values of idling angles. It is found that an increase in the idling angle of the rotary valve of GM refrigerator reduces its cooling capacity and enhances its specific cooling capacity. An experimental study has also been undertaken to corroborate the mathematical results.

DNA Memristors and Their Application to Reservoir Computing.

This paper introduces memristors realized by molecular and DNA reactions. Molecular memristors process one input molecule, generate two output molecules, and are realized using two molecular reactions with two different rate constants. The DNA memristors are realized using five DNA strand displacement (DSD) reactions with two effective rate constants. The hysteresis behavior is preserved in the proposed memristors, and this behavior can be altered by changing the ratios of the rate constants. The state of the memristor can be computed from the concentrations of the two output molecules using bipolar fractional coding. We describe how the proposed memristors can be used to learn the spatial and temporal properties of data via the reservoir computing (RC) model. An RC system can be divided into two parts: reservoir and readout layer. The first part transfers the information from the input space to a high-dimensional spatiotemporal feature space represented by the state of reservoirs. The connectivity structure of the reservoir will remain fixed through the dynamical evaluations. The readout layer effectively maps the projected features to the target output. A dynamical memristor array is used to implement an RC system that exploits the internal dynamical processes of the memristors. The readout layer implements a matrix-vector multiplication using molecular reactions, also based on bipolar fractional coding. All molecular reactions are mapped to DSD reactions. The RC system based on the DNA reservoir and the DNA readout layer is used to solve a handwritten digit recognition task and a second-order time series prediction task. The performance of the DNA RC system is comparable to that of an electronic memristor RC system for both tasks.

Study of the effect of geological and geomorphological parameters on soil erosion and sediment yield of Gabrik River basin, S.E Iran

The Gabrik River basin is located in the Makran zone in southeast of Iran. This basin is characterized by specific geomorphological features related to its geological characteristics and geographical location. The present study investigates the attempts to minimize the negative effects of sediment accumulation behind the Gabrik dam in this region. Therefore, the main objectives of this research are to study the geomorphological status of the basin and analyze the sensitivity of geological units to erosion. Investigation of geomorphological forms of the Gabrik basin indicates that the internal (tectonic) and external (erosion and sedimentary processes) dynamic processes have a significant role in the basin evolution. The results could be used to identify the potential areas for erosion and sediment production. To estimate the sediment erosion and yield, the Gabrik basin was divided into two hydrological units (i.e., HU1 and HU2). Then, the required information to determine nine factors of the MPSIAC model and five factors of the FSM model were provided and determined for each unit. Afterward, the soil erosion maps were extracted in ArcGIS software. As a result, the rate of sediment yield from MPSIAC and FSM models was determined 4 and 6.23 tons per hectares, respectively. The findings of this research indicate the importance of tectonics, lithological units, and climate on erosion rate, sediment production, and geomorphology of the Gabrik basin. Also, according to the results from erosion maps, it was revealed that the soil erodibility in the Gabrik area is low to medium. So, in these areas, the implementation of soil and water conservation programs is essential.

Improved gray wolf particle filtering and high‐fidelity second‐order autoregressive equivalent modeling for intelligent state of charge prediction of lithium‐ion batteries

The rapid development of new energy vehicles puts forward higher requirements for the lithium-ion batteries model construction, high-efficiency condition monitoring and collaborative estimation. An improved high-fidelity second-order autoregressive model is proposed and constructed, and the autoregressive model is integrated with the second-order equivalent circuit model, which can achieve an accurate and reliable description of the batteries internal dynamic change process. To achieve the accurate expression of the battery's external characteristics and internal state, the forgetting factor is combined with the recursive least square algorithm to improve the parameter identification accuracy and optimality while reducing the space complexity of the algorithm. A novel gray wolf particle filtering algorithm is proposed, which eliminates the particles severe degradation in traditional algorithms and enhances the ability of particles to resist degradation. The algorithm superiority and generalization are verified under complex working conditions. The experimental results show that the accuracy of the high-fidelity second-order autoregressive model can reach 99%, which can well simulate the complex chemical reaction process inside the lithium-ion battery. Experimental simulation is performed under constant current conditions. Compared with the extended Kalman filter, unscented Kalman filter, and particle filter algorithms, the gray wolf particle filter algorithm has reduced the root mean square error by 3.39%, 0.90%, and 2.84%, and the mean absolute error has reduced by 1.95%, 0.51%, and 2.22%. Under dynamic stress test conditions, the root mean square error is reduced by 1.54%, 0.33%, and 0.78%, and the average absolute error is reduced by 1.4%, 0.22%, and 0.76%. In addition, when tested under different environmental conditions, although the improved algorithm has a relatively long running time, the estimation accuracy of the algorithm is greatly improved and the execution efficiency is high. The improved algorithm provides a theoretical basis for the reliability and stability of the onboard operation of lithium-ion batteries. Highlights A novel lithium-ion battery high-fidelity second-order autoregressive equivalent model is proposed. The gray wolf particle filter is employed to improve the observation accuracy. A recursive calculation method is derived by the time-based parameters.