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The Tibetan Plateau (TP), a crucial area influencing global climatic patterns and water resources, is experiencing a unique climatic paradox, particularly evident in the Three Rivers Source Region (TRSR). A striking summer asymmetry in the increases of near-surface temperature and precipitation is observed from 1989 to 2018: the rate of daily minimum temperature (0.64°C decade−1) surpasses the daily maximum temperature (0.52°C decade−1), while the daytime precipitation intensity (0.40 mm day−1 decade−1) increases at a faster rate compared to nighttime (0.30 mm day−1 decade−1). Despite these trends, the summer mean nighttime precipitation intensity consistently remains higher than the daytime average. Notably, this pattern is accompanied by an increasing trend of moisture transport during both daytime and nighttime in TRSR. This paper deciphers the thermodynamic and dynamic processes behind this trend. The daytime warmth not only alters the stability of atmosphere but also modulates convective inhibition (CIN), thereby reshaping precipitation mechanics and potentially dampening or delaying daytime convection. Thermodynamically, a shift from unstable to stable anomalies in the summer troposphere suppresses precipitation development. The combination of increased CIN during those period leads to fewer but more intense rainy days. Dynamically, the shift from a consistent downward motion anomaly throughout troposphere to an upward motion anomaly becomes dominant during nighttime, exhibiting a similar transition but only below 500 hPa during daytime. These findings reveal the complex interplay between thermodynamics, dynamics, and precipitation, highlighting the need for refined climatic models that can accurately simulate these summer diurnal processes. [ABSTRACT FROM AUTHOR]

Climate warming has caused widespread glacier retreat across the Tibetan Plateau (TP), with notable impacts observed in both the western Himalayas and southeastern TP. Remarkably, over the past two decades, the rate of glacier mass loss has remained stable or even declined in the western Himalayas, whereas a contrasting trend of acceleration has been evident in the southeastern TP. Among various factors considered, the contrasting winter precipitation pattern across the Himalayas–southeastern TP stands out as an important contributor to the observed differences in glacier mass balances. However, the underlying mechanisms behind this phenomenon remain unclear. Here, we provide evidence of a noticeable shift in the climate regime due to anthropogenic warming, altering atmospheric circulation patterns. This, in turn, has led to a significant change in the dominant winter precipitation pattern, favoring the observed contrasting glacier mass balances trend in winter. Additionally, the Barents–Kara Sea ice has emerged as a plausible driver of the interannual variability of the contrasting precipitation pattern, acting by exerting force on the atmosphere and stimulating the Rossby wave propagation. Consequently, it led to the opposite vertical motion and alterations in the moisture budget between the western Himalayas and southeastern TP. Thus, it is crucial to consider the unprecedented anthropogenic warming and Arctic Sea ice variations as potential drivers shaping both past and future glacier behaviors within this domain. [ABSTRACT FROM AUTHOR]

We compared elevation trajectories from 14 rod surface elevation table (RSET) stations and 60 real-time kinematic (RTK) global positioning system (GPS) transects within the Blackwater National Wildlife Refuge (BNWR) from 2010–2013. The results were similar, 7.3 ± 0.9 (mean ± standard error; RSET) versus 6.2 ± 0.6 mm year−1 (RTK) (P = 0.216), and were greater than relative sea level rise (RSLR) computed at the nearest long-term tide station (3.9 ± 0.29 mm year−1). Despite having shown elevation gain, these wetlands continue to drown and convert to open water. Episodic, multi-day GPS measurements on geodetic control marks at BNWR between 2005 and 2023 revealed a substantial vertical land motion (VLM) signal. From 2005 to 2015, three reference marks used to control the 2010–2013 RTK study lost on average 6.0 ± 0.7 mm year−1, corresponding to 80% and 94% of the elevation gain measured by the RSET and RTK techniques, respectively. The longer 18-year subsidence trend measured on one of these marks was lower, 3.9 ± 0.7 mm year−1, highlighting important interannual variability. Wetland elevation change measurements need to account for VLM occurring below the reference marks used to measure elevation change. Estimates from the nearest long-term tide station may not be applicable to the wetland if the tide station is in a different geological setting. At BNWR, VLM was higher than the VLM at the Cambridge tide station, which helps explain why wetlands at BNWR are not keeping pace with RSLR despite the measured high rates of elevation gain. [ABSTRACT FROM AUTHOR]

The thematic issue entitled, "Current Advances in Coastal Wetland Elevation Dynamics," draws on topics from two special sessions at the CERF 2021 conference plus additional recent research describing scientific insights gained from the Surface Elevation Table–Marker Horizon (SET–MT) method and its application across the globe to quantify and understand subsurface process influences on wetland elevation change and wetland responses to sea-level rise. The findings group articles within each of five thematic topics. (1) A 30-year retrospective on the scientific insights gained on surface and shallow subsurface process dynamics. (2) Investigations of the subsurface soil process influences on wetland elevation. (3) How the scientific community applies the SET–MH method to quantify and understand wetland responses to RSLR and other environmental drivers such as altered hydrology and sediment supply. (4) How SET–MH data are used in long-term monitoring networks at different geographic scales. (5) Pairing the SET-MH method with (a) survey techniques to increase lateral coverage of wetland elevation trends and (b) geodetic measurements to increase vertical coverage of vertical land motion. [ABSTRACT FROM AUTHOR]

This study investigates the vulnerability of long-span suspension bridges to spatially variable vertical ground motions (SV-VGMs). While of recognized importance, a comprehensive understanding of this topic has been traditionally limited by the unavailability of an adequate number of arrays of motions. In this work, 10 simulations of a large-magnitude Hayward Fault earthquake are utilized to perform site-specific structural response assessments of a suspension bridge under different load scenarios. A detailed nonlinear model representative of the West San Francisco-Oakland Bay Bridge is employed as the case study structure. Four sets of nonlinear time-history analyses are performed with and without VGMs and with and without the incorporation of spatial variability to offer the basis for a complete comparison of the demand distributions across different load cases. Results indicate that VGMs largely influence the response of the bridge decks in the vertical direction, with an increase in drifts up to 2× for the case of synchronous input and up to 2.5× for the case of asynchronous inputs. The analysis of the bridge response in the time and frequency domain across all load cases reveals a high sensitivity of the decks' response to minor time lags in input motions of comparable amplitude, which are seen to activate the contribution of higher modes to the structural response. Evidence from this study points to the potential of severely underestimating structural demands if the (even limited) spatial variability of the input motions is not incorporated correctly. For the case study structure, the probability of exceeding the onset of nonlinearity in the short decks at the design earthquake level is seen to increase by a factor of about two when considering SV-VGMs as opposed to synchronous horizontal motions only. [ABSTRACT FROM AUTHOR]

When daytime tropical convection develops away from mesoscale disturbances, it typically transitions gradually from dry to shallow to deep convection on hourly timescales. The transition is commonly associated with the formation of larger horizontal boundary‐layer structures and an increasing level of cloud organization aloft. This study demonstrates that a spectral analysis of the resolved high‐resolution sub‐cloud flow features allows for a robust identification of dominant length scales and the quantification of their growth rates during the transition. Furthermore, it is shown that temperature, moisture, and horizontal winds develop multiple length scales with the largest ones growing up to several kilometers in magnitude. However, the vertical velocity behaves in a distinct manner developing significantly smaller values, comparable over land and ocean. This indicates stronger inherent limits of vertical velocity to self‐organize by size. Plain Language Summary: When tropical storms form away from big weather systems, they usually go through several stages, starting with shallow clouds and then gradually intensifying until deep clouds with anvils develop. As the transition progresses, larger flow patterns form in the air close to the ground, and the clouds above become more organized. This study found that by looking at high‐resolution modeling data in terms of energy distribution per structure size, we can see how these patterns change and grow over time. It also found that the sizes of temperature, moisture, and horizontal wind patterns are similar to each other and can be several kilometers wide. But the patterns of vertical motion behave differently, staying smaller and not growing as much, whether over land or ocean. This indicates natural limits to how big the structures of vertical air movement can get during the formation of local storms. Key Points: Simulated transition to deep convection over both land and ocean is analyzed using a novel method based on spectral analysisDominant sub‐cloud length scales for temperature, moisture, and wind grow linearly until the onset of deep convectionNotably, vertical velocity length scale remains at much lower values, indicating a weaker tendency to self‐organize by size [ABSTRACT FROM AUTHOR]

It is well known that the flutter performance of a section is sensitive to the changing wind angles of attack. Exploring the thin plate's flutter mechanism under different angles of attack is excellent, which helps understand inner flutter characteristics and ensures structural safety. This study investigated flutter derivatives of a thin plate with an aspect ratio of 40 under different wind angles of attack via the forced vibration technique. The otherness of aerodynamic damping and phase lag under different wind angles, which helps in understanding the flutter mechanism, are analyzed using the bimodal-coupled flutter method. It is shown that coupled vertical–torsional flutter dominated the flutter modality under 0° and 3° wind angles of attack. The critical flutter velocity dramatically decreased with increasing wind angles of attack which is attributed to the increasing negative aerodynamic damping induced by coupled self-excited forces and the decreasing positive aerodynamic damping induced by uncoupled self-excited forces. Moreover, the vertical motion lags behind the torsional motion under the 7° angle of attack, which was totally contrary to other angles of attack. Major works in this study reveal the aerodynamic mechanism of the weakened flutter performance of thin plates under large wind angles of attack and provide a reference for the flutter analysis of thin plates. [ABSTRACT FROM AUTHOR]

A new dedicated coastal sea level dataset called the International Altimetry Service 2024 (IAS2024, https://doi.org/10.5281/zenodo.13208305 , Peng et al., 2024c) has been presented to monitor sea level changes along the world's coastlines. One of the reasons for generating this dataset is the quality of coastal altimeter data has been greatly improved with advanced coastal reprocessing strategies. In this study, the Seamless Combination of Multiple Retrackers (SCMR) strategy is adopted to obtain the reprocessed Jason data for January 2002 and April 2022. The evaluation results show that the data availability of the IAS2024 dataset over global coastal oceans is much higher than that of the European Space Agency Climate Change Initiative version 2.3 (ESA CCI v2.3) dataset. The closure of trend differences (0.16 ± 3.98 mm yr−1) between IAS2024 and Permanent Service for Mean Sea Level (PSMSL) tide gauge data is observed at the global scale, which further demonstrates the good performance of the IAS2024 dataset in monitoring the coastal sea level changes. The altimeter-based virtual stations have been built with the IAS2024 dataset over 0−10 km, 5−15 km and 10−20 km coastal strips, which will contribute to the analysis of coastal sea levels for the ocean community and the risk management for the policy makers. Our study also points out that no obvious variations exist in linear sea level trends from offshore to the coast in most coastal zones. In addition, the vertical land motion (VLM) estimates from the combination of coastal altimeter data with tide gauge records agree well with the University of La Rochelle 7a (ULR7a) Global Navigation Satellite System (GNSS) solution (0.09 ± 2.22 mm yr−1), suggesting that altimeter-derived VLM estimates can be an independent data source to validate the GNSS solutions. [ABSTRACT FROM AUTHOR]

Compound events have become more frequent and diverse under global warming. This study specifically focuses on a type of compound events termed spatially compounding flood-nocturnal heat events over adjacent regions. Five flood hotspots are identified to compound with adjacent nocturnal heat. The flood and nocturnal heat are linked via a water vapor transport belt, with flood over the region of prominent water vapor convergence and ascending anomalies and nocturnal heat over the extension region with moderately increased humidity and weak vertical motion anomaly. The compound events for all the hotspots occur more frequently recently, with commonly positive contribution from the increasing trends of nocturnal temperature (TN) but various contribution from the trends of precipitation (Pr) and Pr-TN correlation. The positive contribution of enhanced Pr-TN correlation results from the enhanced variability of the circulation accompanied with water vapor transport. This study highlights the influence of atmospheric circulation variability on compound events. [ABSTRACT FROM AUTHOR]

Due to relatively high terrain and negligible active tectonics, the southern Africa region boasts over 30 independent estimates of dynamic topography. These published estimates display a wide variance due to both the variety of methods used in computation and a lack of constraints on the regional mantle structure. Here we show that a focus on regional mantle structure is important to generate models of lithospheric and mantle dynamics. Global average mantle properties are not representative of a particular region, and it is necessary to generate viscosity profiles specific to a region of interest. We develop a Bayesian inversion using dynamic geoid kernels, existing seismic tomography models, and Slepian functions to invert for a localized radial viscosity profile that best explains the geoid in southern Africa. With an understanding of viscosity uncertainty, we constrain dynamic topography in southern Africa to lie between 1,000 and 2,000 m. Additionally, we model vertical displacements from 112 Global Navigation Satellite System stations across our region to examine the long‐term, long wavelength pattern of present‐day vertical motion, suggesting that a mean of 1.5 mm/yr (1σ $\sigma $: 0.8–2.0 mm/yr) of vertical motion may be related to ongoing dynamic topography. Our study demonstrates the utility of dynamic geoid kernels in local nonlinear inversions of non‐unique geophysical data. Furthermore, we present evidence that the mantle beneath southern Africa is generating significant dynamic support for and vertical displacement of the lithosphere in this region. Plain Language Summary: The high topography of southern African is a result of the interaction between the lithosphere and the mantle beneath the region, a process referred to as dynamic topography. The viscosity of Earth's mantle is a primary driver of the buoyancy forces that generate this dynamic topography. There is significant disagreement regarding the amplitude and pattern of dynamic topography in this region, partially owing to the lack of constraints on inputs to geodynamic models, especially viscosity. We use the geoid to constrain mantle viscosity within our study region by combining existing statistical techniques in a novel manner. We generate models of mantle viscosity, dynamic topography, and present‐day vertical displacement for our study region. Our preferred model results in 1,000–2,000 m of dynamic topography, suggesting that the whole of southern Africa is dynamically supported. We also find evidence for around 1.5 mm/yr (1σ $\sigma $: 0.8–2.0 mm/yr) of present‐day vertical displacement within the southern part of the region, suggesting that dynamic topography is currently increasing. We argue that the viscosity within any given region of the mantle differs significantly from the whole‐mantle average, and care must be taken to use a viscosity model that corresponds to the region of interest when creating geodynamic models. Key Points: We generate Bayesian estimates of localized radial mantle viscosity and dynamic topography in southern AfricaWe model present‐day vertical displacement of southern African using Global Navigation Satellite System station timeseries and Slepian localization techniquesThere is evidence for significant dynamic support (>1,000 m) and present‐day vertical motion (1s: 0.8–2.0 mm/yr) due to mantle dynamics [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to evaluate three‐dimensional vertical motion of the superior surface of the vocal folds in vivo in (a) typically developing children as a function of vocal frequency variations and (b) a child with vocal nodules. Methods: A custom developed laser endoscope coupled with high‐speed videoendoscopy was used to obtain 3D parameters from 2 healthy children, one child with vocal nodules, and 23 vocally healthy adults (females = 11, males = 12). Parameters of amplitude (mm), maximum opening/closing velocity (mm/s), and mean opening/closing velocity (mm/s) were computed for the lateral and vertical vibratory motion along the anterior, middle, and posterior sections of the vocal folds were computed. Results: We provide for the first time, absolute measurements of vertical amplitude and maximum/ mean velocity during the opening and closing phases, in vivo in children. Overall, the vertical motion was larger in vocally normal children compared with the lateral motion, especially along the visible posterior section of the vocal folds and during low pitch phonation. The opening phase dynamics were consistently large along the posterior section in the child with vocal nodules. Conclusions: The study findings establish the feasibility of capturing 3D motion in a clinical setting and provide proof of concept for the application of the proposed 3D laser in the pediatric population. Future large sample size studies are needed to establish the diagnostic potential of examining the closing phase vertical motion to evaluate vibratory development in children with normal voice and investigating the opening phase vertical motion in children with nodules. Level of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Zircons are the oldest remaining witnesses of Earth's near-surface processes, and conditions in the Hadean and Archaean crust are derived predominantly from their trace element and isotopic compositions. However, quantitative assessment of element and isotope partitioning between zircon and melt remains incomplete. We experimentally determined the effect of phosphorus (P) abundance on zircon-melt partition coefficients of Al (DAl), Li (DLi), and P (DP). Results indicate that P content has opposite effects on DAl and DLi, whereas the partitioning of P itself and other trace elements is independent of P abundance. Parametrization of our results yields new assessments of the aluminum saturation index (ASI) and P and Li contents of Hadean magmas. Magma ASI values are ~0.5 lower than previously thought and consistently remain below 1 during the first ~1 Ga of Earth evolution, suggesting involvement of only igneous protoliths. First peraluminous (ASI > 1) melts do not appear until ca. 3.6 Ga, supporting the hypothesis that a transition from a tectonic style dominated by vertical motion to horizontal tectonics accompanied by partial melting of sediments did not occur before that time. New calculated magma Li concentrations for young zircons are in much better agreement with the continental crust Li abundance. Average calculated Archaean and Hadean magma Li concentrations are unrealistically large (>1000 ppm), suggesting that Li in zircons formed before 2 Ga is not primary. Calculated magma P abundances are uniform (~1900 ± 400 ppm) throughout Earth history, suggesting sufficient crustal P was available throughout the Hadean to support the origin of life. [ABSTRACT FROM AUTHOR]

The gymnasium is mainly composed of truss structure, with a large span, and requires high seismic performance. To ensure greater stability of the truss structure, modal analysis was conducted on the mechanical model, yielding the natural frequencies and modal shapes. In order to improve the seismic performance, BRB rods were added to the support points, and the frame structure was reinforced with diagonal braces. Through modal verification, it can be seen that the stiffness of the truss structure was significantly improved. The internal forces of the truss were simulated under the El Centro and Taft seismic wave conditions. The results show that the optimized structure can significantly reduce the internal forces and improve the overall seismic performance. The fundamental natural period of the reinforced structure is less than that of the unreinforced structure, and the stiffness of the reinforced steel structure increases, making it more sensitive to vertical seismic motion. [ABSTRACT FROM AUTHOR]

The long-line abalone culture system in the bottom waters outside the bay is a new type of aquaculture facility that utilizes the underwater attenuation effect of waves to achieve better wind and wave resistance. Currently, most of the research on long-line aquaculture systems is aimed at the sea surface, and the research on the seabed is still pending. Therefore, to ensure the abalone culture system’ s survival rate and structural safety, it is of great significance to study the dynamic characteristics of the long-line abalone culture system in the bottom waters. Based on the similarity criterion, a model test was carried out in the wave-current flume laboratory; a numerical simulation method of the dynamic response of the long-line abalone culture system in the bottom waters was established based on the centralized mass model, and the accuracy of the numerical simulation method was verified. In view of the actual sea conditions off Luoyuan Bay, Fujian Province, the dynamic characteristics of the long-line abalone culture system in the bottom waters were numerically simulated under the action of different waves and currents to analyze the effects of the wave heights, current velocities and flow directions on the stresses on the abalone culture system and the structural safety of the system. The effects of wave height, current speed, and flow direction on the force and trajectory of the system were analyzed. The results show that the numerical model is consistent with the model test results: the maximum relative error of the maximum cable tension measured against the waves is 8. 33%, the minimum relative error is 4. 84%, and the average relative error of the peak horizontal and vertical motions of the float A is 5. 23% and 8. 92% respectively, which proves that the numerical simulation method used in this paper is accurate and reliable; there is a significant difference in the distribution of the force of the long-line and the anchor rope, and the force curve of the long-line shows an arch of the force. The force distribution of the long-line and the anchor rope has obvious differences; the force curve of the long-line shows an arch shape and a sawtooth shape, and the maximum force section is not on the anchor rope but located in the middle region of the long-line; the wave height has a linear relationship with the maximum force of the system and the motion amplitude of the abalone cage, i. e., the higher the wave height is, the larger the transverse and vertical motion amplitude of the system is, and the larger the maximum tension in the middle part of the long-line, the supporting rope and the anchor rope is, and the peak tension curve of the supporting rope shows a sawtooth shape; the maximum tension of the anchor rope in the headward side appears nonlinearly when the velocity of the current is increasing, the maximum tension of the anchor rope in the headward side appears nonlinearly. When the flow velocity increases, the maximum tension of the anchor rope on the headwater side shows a nonlinear steep increase. The maximum tension of the long-line on the headwater side increases slowly, and the maximum tension of the anchor rope and the long-line on the backwater side decreases significantly. In contrast, the maximum tension of the branch ropes does not increase significantly with the flow velocity, and the maximum tension of each branch rope is the same; when the flow direction increases, the maximum tension of the system’s anterior part of the longline and the anchor rope decreases. The posterior part of the long-line and the anchor rope increases, and the branch ropes’ tensions remain relatively stable. The results of this study can provide a reference for the structural design of similar long-line abalone culture systems in the bottom waters. [ABSTRACT FROM AUTHOR]

The availability of reasonable input ground motions is a prerequisite for investigating the seismic response of near-fault structures. Currently, realistic near-fault pulse-like seismic records are lacking internationally. Moreover, the existing records exhibit distinct regional characteristics, which hardly meet the demand for seismic analysis of various engineering structures. Collecting and analyzing the pulse-like seismic records, a linear attenuation expression is proposed in this study to describe the time-varying frequency amplitude decay over duration. On this basis, a new model compatible with horizontal and vertical components is developed for near-fault ground motions. The model parameters are estimated for 100 near-fault records and regressed against the prediction equations. The variability and correlation of the ground motion in two directions are analyzed through the residual correlation matrix. Finally, taking a subway station as the engineering background, the effects of velocity pulse and vertical seismic motions on the underground structures are addressed through simulated motions and realistic records. Compared with existing approaches, the proposed method not only aligns with the time-frequency distribution characteristics of near-fault ground motions but also considers the correlation between horizontal and vertical components. In addition, consistent with the results from recorded ground motions, the synthetic motions yield enlarged seismic responses of the underground structure, thereby guaranteeing analysis accuracy for the engineered structures subjected to pulse-like ground motions. The inclusion of vertical excitation prominently amplifies the vertical displacement of the slab under pulse-like ground motions. [ABSTRACT FROM AUTHOR]

A human laryngeal model, incorporating all the cartilages and the intrinsic muscles, was reconstructed based on MRI data. The vocal fold was represented as a multilayer structure with detailed inner components. The activation levels of the thyroarytenoid (TA) and cricothyroid (CT) muscles were systematically varied from zero to full activation allowing for the analysis of their interaction and influence on vocal fold dynamics and glottal flow. The finite element method was employed to calculate the vocal fold dynamics, while the one-dimensional Bernoulli equation was utilized to calculate the glottal flow. The analysis was focused on the muscle influence on the fundamental frequency (fo). We found that while CT and TA activation increased the fo in most of the conditions, TA activation resulted in a frequency drop when it was moderately activated. We show that this frequency drop was associated with the sudden increase of the vertical motion when the vibration transited from involving the whole tissue to mainly in the cover layer. The transition of the vibration pattern was caused by the increased body-cover stiffness ratio that resulted from TA activation. [ABSTRACT FROM AUTHOR]

A detailed geomorphological mapping allowed to understand the complex relationships interplayed between local tectonics and sedimentation across the coastal area of the Baixo Alentejo (Portugal) all along the Quaternary. Different outcrops of coastal sediments between Sines and Vilanova de Milfontes permitted to reconstruct a general sequence of up to fifteen stair-cased marine terraces, while wide sequences of alluvial fans develop in the hinterland. The distinct geomorphological disposition of these alluvial fans together with the presence/absence of marine terraces, have allowed to define different phases of paleolandscape evolution based both in sea level changes and differential uplift. A dune system has been attributed to MIS 5e in basis of OSL, and 14C and U-series dating permitted the adscription of a beach unit to MIS 5. These data allowed to stablish the relative chronology of the entire marine terrace sequence and to determine the vertical movement rates along the studied coastal area. The results give values ranging from slight uplift (+0.015mm/a) to subtle subsidence (−0.030 mm/a), coinciding with other author's determinations. [ABSTRACT FROM AUTHOR]

Changes in the activities of the Boreal Summer Intraseasonal Oscillation (BSISO) at the end of 21st century under the SSP5-8.5 scenario are assessed by adopting 17 CMIP6 models and the weak-temperature-gradient assumption. Results show that the intraseasonal variations become more structured. The BSISO-related precipitation anomaly shows a larger zonal scale and propagates further northward. However, there is no broad agreement among models on the changes in the eastward and northward propagation speeds and the frequency of individual phases. In the western North Pacific (WNP), the BSISO precipitation variance is significantly increased, at 4.62% K−1, due to the significantly increased efficiency of vertical moisture transport per unit of BSISO apparent heating. The vertical velocity variance is significantly decreased, at −3.51% K−1, in the middle troposphere, due to the significantly increased mean-state static stability. Changes in the lower-level zonal wind variance are relatively complex, with a significant increase stretching from the northwestern to southeastern WNP, but the opposite in other regions. This is probably due to the combined impacts of the northeastward shift of the BSISO signals and the reduced BSISO vertical velocity variance under global warming. Changes in strong and normal BSISO events in the WNP are also compared. They show same-signed changes in precipitation and large-scale circulation anomalies but opposite changes in the vertical velocity anomalies. This is probably because the precipitation anomaly of strong (normal) events changes at a rate much larger (smaller) than that of the mean-state static stability, causing enhanced (reduced) vertical motion. [ABSTRACT FROM AUTHOR]

• An adaptive backstepping controller based on nonlinear filter Lyapunov function is designed. • Integration of body control objectives and hard constraints into one control variable. • An adaptive backstepping bottom controller based on nonlinear disturbance observer is designed. • Conduct stability analyses of zero-power systems to ensure that safety performance indicators are bounded. • Backstepping dynamic surface control is used to avoid the derivative explosion phenomenon. In order to improve the ride comfort and handling stability of the electro-hydraulic active suspension system, a hierarchical control strategy is proposed. For the active suspension system with body mass uncertainty and safety constraints, an enhanced constraint adaptive backstepping controller is designed to generate the target force of body vertical motion. When dealing with constraints, nonlinear filters are introduced, backstepping technology and quadratic Lyapunov function are used to combine the control target and domain constraints, and the vertical displacement of the body and the suspension deflection control index are synthesized into a single controlled variable, so that the control variable converging to zero meets the suspension dynamic displacement limit. The ride comfort and safety of the active suspension system are improved. Secondly, stability analysis is conducted on the zero dynamic error system to ensure that all safety performance indicators are bounded. The effects of external disturbances, parameter uncertainties and modelling errors on the force tracking accuracy of asymmetric cylinder electrohydraulic systems are addressed. A backstepping dynamic surface control method based on a nonlinear perturbation observer is proposed, which estimates the composite perturbation terms such as modelling error and external perturbation, and uses the estimated value of the nonlinear observer to design a feedforward compensating control term to offset the effect of the composite perturbation on the system performance. In addition, the dynamic surface control method is used to calculate the derivative of the target force input, which avoids the derivative explosion phenomenon and reduces the computational complexity of the system. Simulation test results show that this method reduces the computational complexity of the system and improves the control performance. And under random and bumpy road conditions, the root-mean-square value of sprung mass acceleration performance index is reduced by 48.354 % and 72.677 % compared with passive suspension, which improves the ride comfort of the vehicle. [ABSTRACT FROM AUTHOR]

In the paper the discrete linear quadratic optimization problem, where, over a certain part of the time interval, some coordinates of the control actions are known constants. These equalities in the form of a penalty function with a certain weight are added to the quadratic functional and the corresponding discrete Euler-Lagrange equation is constructed, the solution of which is constructed using a discrete fundamental matrix. Then, an explicit expression of control actions over the entire time interval is given. The results are illustrated using the example of the vertical motion of a flying vehicle. [ABSTRACT FROM AUTHOR]

Sea ice edges play an essential role in the Earth's climate and weather systems through active atmosphere‐ice‐ocean interactions. However, our understanding of the observed positions of sea ice edges remains limited. The present study investigated, on seasonal and longer timescales from 1979 to 2023, the variability in sea ice edge positions in the Barents and Greenland Seas. We objectively derived the positions of sea ice edges based on satellite‐derived sea ice concentration gridded on a 25‐km resolution. In the Barents Sea, warm, narrow currents flow eastward along the northern and southern rims of the Central Bank. Until the mid‐2000s, sea ice edges fluctuated between these currents interannually during December–June, depending on the surface wind direction. However, after the mid‐2000s, the sea ice edges were mostly positioned near the northern current or farther to the north. Furthermore, sea ice edges during October–March were identified frequently near the warm current flowing along the continental slope in the northern Barents Sea after the mid‐2000s. In the Greenland Sea, sea ice edges were typically positioned near the East Greenland Current (EGC) throughout the year until 2006. However, sea ice edges in summer were located far to the west of the EGC after 2006. These observations suggest that the geographical relationship between sea ice edges and ocean currents has changed due to global warming. Plain Language Summary: Sea ice edges in the Arctic play an important role in the Earth's climate system. They can strengthen atmospheric cyclones and vertical motion in the atmosphere and the ocean in the Arctic by inducing intense heat and moisture releases from the ocean to the atmosphere. Furthermore, they could exert distinct impacts on global‐scale atmosphere and ocean circulations. Therefore, a deeper understanding of the geographical positions of sea ice edges is essential for elucidating the climate system. This study investigated the sea ice edge positions in the Barents and Greenland Seas using satellite observations from 1979 to 2023. Sea ice edges rapidly advance southward during winter. Until the mid‐2000s, sea ice edges were frequently identified along warm ocean currents in the Barents and Greenland Seas because warm currents obstruct further sea ice edge advances. However, sea ice edges have shifted far to the north of warm ocean currents after the mid‐2000s in association with the recent shrinking in sea ice extent due to global warming. The change in sea ice edge positions might have affected the atmosphere and ocean circulations globally, which should be addressed in future studies. Key Points: In the central Barents Sea, sea ice edge positions fluctuated in winter until the mid‐2000s but have lately fixed along a warm currentSince the mid‐2000s, sea ice edges have been frequently identified along the continental slope in the northern Barents Sea in winterUntil 2006, sea ice edges in the Greenland Sea were located at the East Greenland Current, but they shifted far west after 2006 in summer [ABSTRACT FROM AUTHOR]

Submarine volcanic eruptions can induce major local and regional tsunami hazards through varied source mechanisms. Large‐scale experiments of tsunamis generated by submarine volcanic eruptions are conducted to study the cylindrical wave generation and propagation in a three‐dimensional wave basin. A unique volcanic tsunami generator (VTG) was deployed at the bottom of the wave basin to generate volcanic tsunamis with repeatable and controlled source parameters. The physical modeling is based on the generalized Froude number defined with the VTG velocity and the near source water depth. The pneumatically driven vertical stroke motion generates leading elevation waves in the wave basin. The tsunami waves generated by the VTG are measured with a wave gauge array. The wave maker performance is characterized by the dimensionless leading wave amplitudes and periods. The experimental data show the variations of the leading wave amplitude, period, and celerity along the radial propagation distance. The generated cylindrical waves belong to the weakly nonlinear wave regime in the near field with decaying wave amplitude along radial propagation. The attenuation rate of the leading wave exceeds the range from the linear wave theory in runs with higher Froude numbers. The dimensionless leading wave period increases with the dimensionless propagation distance due to the dispersion relation. Empirical equations for the characteristic wave parameters such as amplitudes and periods are derived. The experimental results contribute to the understanding of volcanic tsunami generation processes and may serve rapid volcanic tsunami hazard assessments as well as the advancement and validation of numerical models. Plain Language Summary: Tsunami hazards generated by non‐tectonic sources such as submarine volcanic eruptions have received more attention recently to understand their generation mechanisms and advance tsunami warning systems. Underwater eruptions with explosive energy can trigger catastrophic tsunamis such as the 1883 Krakatau and 2022 Tonga events. It's generally dangerous to directly observe an eruption and particularly challenging to collect remote sensing field data for underwater or partially submerged volcanoes. In order to understand the tsunami generation, an individual mechanism is isolated. A submarine volcano is physically modeled in the wave basin with a unique pneumatically driven volcanic tsunami generator. The tsunami waves generated with the experimental setup are measured with cameras and wave gauges. Based on the measured data, predictive equations are compared with existing studies. The experimental results can support the development of rapid tsunami hazard assessments for future events. Key Points: A volcanic tsunami generator with pneumatically controllable vertical motion is deployed for physical modeling of point source tsunamisExperiments encompassing submerged, daylighting, and surface piercing scenarios are conducted to measure the cylindrical wave parametersEmpirical equations are proposed to evaluate the wave characteristics of the cylindrical leading elevation waves [ABSTRACT FROM AUTHOR]

This study uses a unique combination of geostationary and low‐Earth orbiting satellite‐based lightning and precipitation observations, respectively, to examine the evolution of deep convection during the tropical cyclone (TC) lifecycle. The study spans the 2018–2021 Atlantic Basin hurricane seasons and is unique as it provides the first known analysis of total lightning (intra‐cloud and cloud‐to‐ground) observed in TCs through their extratropical transition and post‐tropical cyclone (PTC) phases. We consider the TC lifecycle stage, geographic location (e.g., land, coast, and ocean), shear strength, and quadrant relative to the storm motion and environmental shear vectors. Total lightning maxima are found in the forward right quadrant relative to storm motion and downshear of the TC center, consistent with previous studies using mainly cloud‐to‐ground lightning. Increasing environmental shear focuses the lightning maxima to the downshear right quadrant with respect to the shear vector in tropical storm phases. Vertical profiles of radar reflectivity from the Global Precipitation Measurement mission show that super‐electrically active convective precipitation features (>75 flashes) within the PTC phase of TCs have deeper mixed phase depths and higher reflectivity at −10°C than other phases, indicating the presence of more intense convection. Differences in the net convective behavior observed throughout TC evolution manifest in both the TC‐scale frequency of lightning‐producing cells and the intensity variations amongst individual convective cells. The combination of continuous lightning observations and precipitation snapshots improves our understanding of convective‐scale processes in TCs, especially in PTC phases, as they traverse the tropics and mid‐latitudes. Plain Language Summary: Tropical cyclones (TCs) are a global weather phenomenon that can cause significant damage, especially to densely populated coastal regions. TCs are characterized by convective elements that produce intense precipitation and sometimes grow strong enough to produce lightning. However, little is known about convective attributes of TCs as they traverse the mid‐latitudes and undergo extratropical transition. This study uses new satellite observations of the mid‐latitudes to examine how the nature of convection changes throughout the TC lifestyle. Satellite‐observed total lightning (cloud‐to‐ground + intra‐cloud) maxima in tropical storms primarily occur on their right side of the storm motion vector and downshear of their center. Differences in environmental shear shift the observed lightning maxima during the tropical storm phase and play a larger role in precipitation distribution than motion. Satellite‐based radar observations indicate that electrically active convective precipitation features are deeper, have stronger vertical motions, and more intense rainfall than their non‐electrically active counterparts. The results of this study reveal new insights about the distribution and intensity of convective elements within TCs, which could be incorporated into TC assessments and help improve forecasts. Key Points: This study provides the first characterization of lightning in tropical cyclones (TCs) that have undergone extratropical transitionLightning activity within TCs exhibits a unimodal radial distribution as well as for tropical storm and extratropical phasesTC phase convective differences are driven by both the frequency of lightning producing cells and intensity differences among them [ABSTRACT FROM AUTHOR]

Earth's climate sensitivity depends on how shallow clouds in the trades respond to changes in the large‐scale tropical circulation with warming. In canonical theory for this cloud‐circulation coupling, it is assumed that the clouds are controlled by the field of vertical motion on horizontal scales larger than the convection's depth (∼ ${\sim} $ 1 km). This assumption has been challenged both by recent in situ observations, and idealized large‐eddy simulations (LESs). Here, we therefore bring together the recent observations, new analysis from satellite data, and a 40‐day, large‐domain (1600×900 $1600\times 900$ km2) LES of the North Atlantic from the 2020 EUREC4A field campaign, to study the interaction between shallow convection and vertical motions on scales between 10 and 1,000 km (mesoscales), in settings that are as realistic as possible. Across all data sets, the shallow mesoscale vertical motions are consistently represented, ubiquitous, frequently organized into circulations, and formed without imprinting themselves on the mesoscale buoyancy field. Therefore, we use the weak‐temperature gradient approximation to show that between at least 12.5–400 km scales, the vertical motion balances heating fluctuations in groups of precipitating shallow cumuli. That is, across the mesoscales, shallow convection controls the vertical motion in the trades, and does not simply adjust to it. In turn, the mesoscale convective heating patterns appear to consistently grow through moisture‐convection feedback. Therefore, to represent and understand the cloud‐circulation coupling of trade cumuli, the full range of scales between the synoptics and the hectometer must be included in our conceptual and numerical models. Plain Language Summary: The tropical oceans are covered by shallow cumulus clouds, partially controlled by a gentle downward vertical motion associated with large (larger than 1,000 km) tropical circulations. Changes in these circulations, for example due to warming climate, can therefore change the shallow cloudiness, and their climatological cooling. Hence, understanding this cloud‐circulation coupling is an important challenge. Here, we study the cloud‐circulation coupling over areas of tens to hundreds of kilometres ("mesoscales") in simulations, field observations and satellite data of unprecedented detail. We find that in mesocale domains, circulations do not just control shallow clouds, as historically thought. Instead, the heating in clusters of rainy cumuli drives the circulations, as suggested by recent idealized simulations. The question is then: what controls these mesoscale cloud patterns? In the detailed simulations, they develop in unusually moist layers, which are further moistened by the circulations. Since moister layers support more clouds, the clouds and circulations grow together. Hence, our results show that on top of the classical sketch of clouds responding to large circulations, lies a dynamic mesoscale picture of two‐way interactions between the two, which we must understand if we wish to predict the distribution of clouds over the tropical oceans in our transient climate. Key Points: A realistic large‐eddy simulation adequately represents vertical motion in shallow mesoscale circulations recently observed in the tradesAt mesoscales, shallow convective heating causes the vertical motion, inverting the classical view that circulations control shallow cloudsWater vapor convergence with the circulations is likely key to develop the mesoscale shallow convection patterns [ABSTRACT FROM AUTHOR]

The visual naturalness of a rendered character's motion is an important factor in computer graphics work, and the rendering of jumping motions is no exception to this. However, the computational mechanism that underlies the observer's judgement of the naturalness of a jumping motion has not yet been fully elucidated. We hypothesized that observers would perceive a jumping motion as more natural when the jump trajectory was consistent with the trajectory of a vertical projectile motion based on Earth's gravity. We asked human participants to evaluate the naturalness of point-light jumping motions whose height and duration were modulated. The results showed that the observers' naturalness rating varied with the modulation ratios of the jump height and duration. Interestingly, the ratings were high even when the height and duration differed from the actual jump. To explain this tendency, we constructed computational models that predicted the theoretical trajectory of a jump based on the projectile motion formula and calculated the errors between the theoretical and observed trajectories. The pattern of the errors correlated closely with the participants' ratings. Our results suggest that observers judge the naturalness of observed jumping motion based on the error between observed and predicted jump trajectories. [ABSTRACT FROM AUTHOR]

The role of mixing between layers of different densities is key to how the ocean works and interacts with other components of the Earth's system. Correctly accounting for its effect in numerical simulations is therefore of utmost importance. However, numerical models are still plagued with spurious sources of mixing, originating mostly from the vertical advection schemes in the case of fixed-coordinate models. As the number of phenomena explicitly resolved by models increases, so does the amplitude of resolved vertical motions and the amount of spurious numerical mixing, and regional models are no exception to this. This paper provides a clear illustration of this phenomenon in the context of simulating the south-east Asian (SEA) seas along with a simple way to reduce its impact. This region is known for its particularly strong internal tides and the fundamental role they play in the dynamic of the region. Using the Symphonie ocean model, simulations including and excluding tides and using a pseudo-third-order upwind advection scheme on the vertical are compared to several reference datasets, and the impact on water masses is assessed. The high diffusivity of this advection scheme is demonstrated along with the importance of accounting for tidal mixing for a correct representation of water masses. Simultaneously, we present an improvement in this advection scheme to make it more suitable for use in the vertical. Simulations with the new formulation are added for comparison. We conclude that the use of a higher-order numerical diffusion operator greatly improves the overall performance of the model. [ABSTRACT FROM AUTHOR]

Large‐scale extreme precipitation (LSExP) events, characterized by widespread extent, persistence, and high intensity, can pose devastating threats to millions of people, infrastructure, and ecology in highly urbanized southeastern China. Here we explore the three‐dimensional (spatial and temporal) characteristics and movements of LSExPs and their direct drivers (vertical velocity, water vapor and moisture advection) under six synoptic‐scale circulation patterns in southeastern China. LSExPs are classified as low‐pressure or non‐low types based on circulation anomaly patterns. The low‐pressure LSExPs are associated with anomalous cyclonic low‐pressure systems in the mid‐ and lower‐troposphere, occurring with main coastal precipitation, while the non‐low LSExPs mainly result from cold‐warm air convergence and primarily affect inland areas. Low‐pressure LSExPs exhibit relatively high intensity compared to non‐low types, particularly on days featuring a south‐low and north‐high dipole pattern, which tend to produce more localized and intense precipitation events. Non‐low LSExPs show larger precipitation areas, longer durations, and greater movement distances, and thus impact wider regions, compared to low‐pressure LSExPs. Single high‐pressure or low‐pressure systems are less likely to result in LSExPs, and LSExPs are less severe if occur, compared to other types. All LSExP types move in a direction similar to that of moisture transport, strongly influenced by extreme upward motion of moisture. Low‐pressure LSExPs are more related to the upward motion of the atmosphere at 850 hPa, and they also involve extreme water vapor and moisture transport. Plain Language Summary: Large‐scale extreme precipitation events can be destructive due to their widespread coverage, persistence, and intensity. In southeastern China, the connection between spatiotemporal three‐dimensional large‐scale extreme precipitation (LSExP) events and weather‐scale circulation patterns has not been established. This study assesses the occurrences, spatiotemporal characteristics, and three‐dimensional behaviors of LSExP events under six identified circulation anomalies over southeastern China. Large‐scale extreme precipitation events can be categorized into the low‐pressure types and the non‐low types based on circulation background characteristics. Low‐pressure extreme precipitation events mainly occur along the southeastern coastal areas and show precipitation of high‐intensity, small‐scale precipitation. Non‐low extreme precipitation events are usually triggered by cold‐warm air convergence and typically cover larger areas, last longer, and travel farther, affecting broader regions. All LSExP events move in a direction similar to that of water vapor transport and are associated with extreme upward motions. Low‐pressure LSExP events are additionally associated with higher precipitable water and moisture transport. This three‐dimensional structural perspective enhances insight into the mechanisms and triggers of catastrophic extreme precipitation events, and could potentially improve precipitation forecasting and adaptation. Key Points: Identified the spatiotemporal evolution features of high‐impact, large‐scale extreme precipitation (LSExP) events over southeastern ChinaLinked synoptic circulation patterns with LSExPs, and explored the occurrence, spatiotemporal features and movements of LSExPs under each patternMost LSExP days are accompanied by extreme vertical motion, and low‐pressure LSExP types are also linked to high precipitable water [ABSTRACT FROM AUTHOR]

• Vertical vergence was triggered by optic flow and visual rotations in all planes. • The degree of vergence was correlated with increased instability and stress. • Visually induced vertical vergence likely reflects subcortical vestibular activity. The present study explored visually induced vertical vergence (VIVV) as non-specific motion processing response. Healthy participants (7 male, mean age 28.57 ± 2.30; 9 female, mean age 27.67 ± 3.65) were exposed to optokinetic stimuli in an HTC VIVE virtual reality headset while VIVV, pupil-size, and postural sway was recorded. The methodology was shown to produce VIVV in the roll plane at 30 deg/s. Subsequent trials consisted of 40 s optokinetic motion in yaw, pitch, and roll directions at 60 deg/s, and radial optic flow; optokinetic directions were inverted after 20 s of motion. Median VIVV amplitude changes were normalized to the clockwise roll rotation, analysed, and correlated with changes in pupil-size and body sway. VIVV, pupil-size, and body sway were all affected by changes in optokinetic direction. Post-hoc analyses showed significant VIVV responses during optokinetic yaw and pitch rotations, as well as during radial optic flow stimulations. VIVV magnitudes were universally correlated with pupil-size and body sway. In conclusion, VIVV was expressed in all tested dimensions and may consequently serve as a visual motion processing biomarker. Failing to support binocularity while responding to optokinetic directionality, VIVV may reflect an eye-movement response associated with increased postural instability and stress, similar to a dorsal light reflex. [ABSTRACT FROM AUTHOR]

This study investigates the mass and heat transfer properties of Ag-H2O nanofluid MHD Forchheimer flows and Ag-MoS2/H2O hybrid nanofluid over two-dimensional linear stretching surfaces in aligned magnetic fields with absorption of radiation. The fluid experiences rotational motion around the vertical axis at a consistent angular speed. The system of nonlinear ODEs is derived from the set of nonlinear PDEs by use of similarity transformations. The BVP-5C shooting approach in MATLAB is then employed to solve the associated system of ODEs. As the Forchheimer number, porosity parameter, rotation parameter and aligned magnetic field exhibit an ascent, the velocity profile along the x-axis and y-axis experiences a decrement. Simultaneously, an augmentation in the magnetic parameter, thermal radiation and rotation parameter induces a heightened temperature profile. Additionally, greater values of the Forchheimer number, rotation parameter and magnetic parameters correspond to an increase in concentration profile. Furthermore, the results indicated an increased temperature profile in the Ag-MoS2/H2O hybrid nanofluid compared to that in the Ag-H2O nanofluid for magnetic, rotation and radiation parameters. Also, the concentration profile of magnetic and rotation parameters along with the Forchheimer number were noted to be higher in the Ag-MoS2/H2O hybrid nanofluid compared to that in the Ag-H2O nanofluid. [ABSTRACT FROM AUTHOR]

Lake outburst events have been mainly focused on small glacial lakes in the Himalaya, while the historical events from inland large lakes are few and have received less attention. Inland large lakes on the Tibetan Plateau are expanding rapidly, with recent signs of increasing outburst risk, highlighting the need to elucidate the processes, causes and mechanisms to mitigate future impacts. Here, a long-term satellite lake mapping shows that the number and surface area of lakes on the Tibetan Plateau over the past 50 years peaked in 2023, accompanied by two notable outburst events: Zonag Lake (~150 km2 in 2023) on 15 September 2011 and Selin Co (~2,465 km2 in 2023, the largest lake in Tibet) on 23 September 2023. The cascading outburst of Zonag Lake caused its area to shrink by ~124 km2 (-45 %), while the downstream Yanhu Lake expanded by ~163 km2 (+347 %). The Selin Co outburst resulted in a water volume loss of ~0.3 Gt, the downstream Bange Co experienced a water level rise of ~2.3 m and an area expansion of ~18 %. Despite its large water storage capacity, Selin Co experienced less water loss due to the flat terrain at the breach and the slow flow (~1 m/s at the damaged road), with an average discharge of ~170 m3/s. Even with the low discharge, the Selin Co flood breached the lowland road within ~12 hours. In contrast, the large breach and steep terrain at Zonag Lake facilitated a rapid discharge of a sustained volume of water, with an average discharge of ~2,191 m3/s. Selin Co resulted in only a short period of drainage reorganization, in contrast to the permanent reorganization caused by Zonag Lake. The underlying mechanisms of the increased precipitation as the main trigger for the two outburst events prior to the occurrence are different. For Zonag Lake, thermodynamic effects, i.e. changes in the atmospheric moisture, are the most important, while for Selin Co, dynamical effects, i.e. the vertical motion induced by the changes in atmospheric circulation, dominate the precipitation patterns. Large lake outbursts in the Inner Tibetan Plateau are expected to increase in the near future due to the warmer and wetter climate, and urgent policy planning is needed to mitigate the potential future lake-induced flood damage. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of different ventilation systems in two aging cells. One cell featured transverse airflow starting from the top, while the other had a dual-flow system with vertical air motion from top to bottom and vice versa. In addition to monitoring weight loss during aging, chemical and physical analyses were conducted on various salamis to assess the influence of ventilation both between the two aging cells and among different positions of the salamis within the same cell. It was found that the dual-evaporator (DEV) cell behaved better than transverse flow (TFL) cell. [ABSTRACT FROM AUTHOR]

Wind gustiness is an effective approach for addressing mesoscale enhancement in estimating air-sea interface fluxes. In this study, an improved convective gustiness parameterization scheme based on convective available potential energy (CAPE) is formulated utilizing reanalysis data and wind observations from moored buoys. This new parameterization was examined by implementing it in the air-sea flux transfer scheme within the National Center for Atmospheric Research Community Earth System Model (NCAR CESM) version 2.1.3 and contrasting it with a previously proposed scheme based on convective precipitation rate. The results indicate a significant reduction in negative biases of surface winds and latent heat fluxes over the tropical Indian Ocean and western Pacific during summer with the implementation of either gustiness scheme, resulting in an average increase in latent heat flux of approximately 9 W·m− 2. Specifically, the CAPE-based scheme shows a more favorable impact in the Indo-Pacific Warm Pool region, whereas the precipitation-based scheme exhibits inferior performance in the western Pacific Intertropical Convergence Zone. Further analysis reveals that the inclusion of the gustiness scheme distinctly alters surface evaporation and latent heat flux, influencing vertical motion in the area with active convective activity and effectively improving precipitation simulations by up to 18%. Moreover, the CAPE-based scheme reduces the bias in summer precipitation simulations by approximately 5% more than the precipitation-based scheme. [ABSTRACT FROM AUTHOR]

In this study, we analyse the large-scale biases in tropical precipitation climatology of two different types of coupled ocean–atmosphere general circulation models (GCMs): the coupled model intercomparison project (CMIP) models and ICON-Sapphire, a global storm-resolving model. We employ the simple globally resolved energy balance (GREB) diagnostic precipitation model to evaluate four drivers of the precipitation biases in the simulations: surface specific humidity, surface relative humidity, tropospheric mean and variability in the vertical motion. The tropical precipitation biases in the CMIP and ICON-Sapphire simulations are surprisingly similar in their patterns and also in the elements forcing them. The results of our analysis using the GREB model show that the precipitation biases result from both biases in the sensitivity to the four forcing fields and biases in the simulated forcing fields themselves. The most significant bias for both, the CMIP and ICON-Sapphire simulations, is a too high sensitivity to the mean vertical circulation ( ω mean ) and bias in the ω mean climatology itself. This also holds for specific long-standing biases, such as the double intertropical convergence zone problem. Meanwhile, biases in the climatology of specific and relative humidity play only a minor role but contribute to an overall small increase in precipitation in CMIP models that may be related to the "drizzling" bias. These results can give insights to the modelling community regarding model development, and illustrate that the GREB diagnostic precipitation model applied is a good tool for evaluating the drivers of large-scale tropical precipitation. [ABSTRACT FROM AUTHOR]

In this study, we apply the moist static energy for first baroclinic mode (MSEB) model to examine the drivers of the mean tropical atmospheric circulation biases over oceanic regions. The model diagnoses the vertical motion in an air column of the tropical regions based on net energy heat flux and advection of moisture or heat into the air column in relation to the stability of the air column due to the gradients in moist static energy. Analysis of Coupled Model Intercomparison Project (CMIP) and Atmospheric Model Intercomparison Project (AMIP) simulations helped to identified errors intrinsic to the atmospheric models or errors due to atmosphere–ocean coupling process. Despite some limitations of the MSEB model, our multi-model mean analysis over the entire tropical ocean reveals that the primary drivers of the tropical circulation biases mostly result from intrinsic atmospheric model errors in top of the atmosphere longwave radiation and surface latent heats fluxes, suggesting a link to biases in the hydrological cycle. Oceanic coupling significantly enhanced some of the biases. Biases in the advection of moist static energy also play an important role, while biases in the gross moist stability profiles play only a minor role. Further, we examine the inter-model variations in four main regional large-scale biases (double-ITCZ, Pacific cold tongue, southward shift of ITCZ over the Atlantic, and dipole bias over the Indian Ocean). The analysis suggests that regional bias patterns across general circulation models are primarily driven by coupling errors, except for the bias in the Indian Ocean, which is intrinsic to the atmospheric model but amplified by coupling. Notably, longwave radiation biases at the top of the atmosphere are prevalent among the four bias patterns, as well as biases in moisture advection over the Atlantic. Our results underscore the significant role of net longwave radiation at the top of the atmosphere, an aspect not sufficiently emphasized in previous studies. [ABSTRACT FROM AUTHOR]

Significant increase in precipitation around the middle and lower reaches of the Yangtze River valley (MLYRV) has been observed in the four months of June/July2020 and May/August 2021. The remarkable thing is, among these four months that belong to different stages of the East Asian summer monsoon (EASM) marching, it is the narrow and elongated westward extension of the Western Pacific subtropical high (WPSH) to the South China Sea (SCS) providing the direct conditions for the sustained rainy belt near MLYRV. The source of the anomalous subsidence core in the SCS which reinforces the westward trend of the WPSH is traced by using the three-pattern decomposition of the global atmospheric circulation (3P-DGAC) method. Quantitative vertical motion decomposition results show that the meridional circulation provides all the positive contributions to the subsidence. Further analysis found that the subsidence core in SCS is part of a particular tripolar meridional circulation anomaly structure which hold one subsiding branch around SCS and two ascending branches nearby the Maritime Continent (MC) and MLYRV. Such Maritime Continent-East Asia tripolar meridional circulation (MCEA-TMC) is confirmed as a typical dominant mode of meridional circulation exist in each month from May to August in the EOF results. Diagnostic study reveals the MCEA-TMC is a specific manifestation of joint effect of the multiple atmospheric factor in different latitudes. The enhanced meridional circulation from the MC to SCS is conducive to westward expansion of the WPSH and abundant water vapor to eastern China. The southward invasion of cold air in the middle-high latitudes meets the warm moist flow and forms convective convergence, limiting the northward expansion of the WPSH and stabilizing the MLYRV rain belt. This study extracted the MCEA-TMC as the stable indicator in reflecting the large scale conditions for the zonal rainy belt in the MLYRV from May to August. [ABSTRACT FROM AUTHOR]

Wave-induced mixing can enhance vertical mixing in the upper ocean, facilitating the exchange of heat and momentum between the surface and deeper layers, thereby influencing ocean circulation and climate patterns. Building on previous research, this study proposes a wave-induced mixing parameterization scheme (referred to as EXP3) specifically designed for typhoon periods. This scheme was integrated into the fully coupled ocean–wave–atmosphere model COAWST and applied to analyze Typhoon In-Fa (2021) as a case study. The simulation results were validated against publicly available data, demonstrating a good overall match with observed phenomena. Subsequently, a comparative analysis was conducted between the EXP3 scheme, the previous scheme (EXP2) and the original model scheme (EXP1). Validation against Argo and Drifter buoy data revealed that both EXP2 and EXP3, which include wave-induced mixing effects, resulted in a decrease in the simulated mixed layer depth (MLD) and mixed layer temperature (MLT), with EXP3 showing closer alignment with the observed data. Compared to the other two experiments, EXP3 enhanced vertical motion in the ocean due to intensified wave-induced mixing, leading to increased upper-layer water divergence and upwelling, a decrease in sea surface temperature and accelerated rightward deflection of surface currents. This phenomenon not only altered the temperature structure of the ocean surface layer but also significantly impacted the regional ocean dynamics. [ABSTRACT FROM AUTHOR]

With the enrichment of GNSS data and the improvement in data processing accuracy, GNSS technology has been widely applied in fields such as crustal deformation. The Crustal Movement Observation Network of China (CMONOC) has provided decades of Global Navigation Satellite System (GNSS) data and related data products for crustal deformation research on the Chinese mainland. The coordinate time series of continuously observed reference stations contain abundant information on crustal movements. In contrast, the coordinate time series of periodically observed campaign stations have limited data, making it difficult to separate or remove instantaneous non-tectonic movements from the time series, as performed with reference stations, to obtain a stable and reliable crustal movement velocity field. To address this issue, this paper proposes a method to improve the estimation of crustal movement velocity at campaign stations using the information of neighboring reference stations. This method constructs a Delaunay triangulation of reference stations and fits the periodic movement of each campaign station using an inverse distance weighted interpolation algorithm based on the reference station information. The crustal movement velocity of the campaign stations is then estimated after removing the periodic movement. This method was verified by its application to the estimation of the vertical motion rate at some reference and campaign stations in Yunnan Province. The results show that the accuracy of vertical motion rate estimation for virtual and real campaign stations improved by an average of 24.4% and 9.6%, respectively, demonstrating the effectiveness of the improved method, which can be applied to estimate crustal movement velocity at campaign stations in other areas. [ABSTRACT FROM AUTHOR]

In order to design a controller to control the pitch and depth of the submarine, this paper designs a submarine bow and stern rudder controller based on Closed-loop Gain Shaping Algorithm (CGSA) and nonlinear feedback and modification. The controller design considers the decoupling of the strong coupling of the submarine vertical surface motion model, the effect of wave disturbance and the optimization of the controller output. To verify the effectiveness and superiority of the proposed method, this research compares it with the Independent channel analysis and design (ICAD) method and introduces an evaluation index system to quantify the improvement effect. From the controller design process, the parameters of the CGSA are simple to solve and the engineering meaning is clear. From the simulation results, this controller can reach the setting depth quickly during the depth-changing maneuver. In the depth-keeping navigation stage, the control effect of depth and pitch angle is improved under wave disturbance, and the control energy evaluation index of the bow and stern rudder are reduced by 94.00% and 77.16% respectively, which proves that the controller has robust performance and energy saving effect. A new and efficient control algorithm is proposed for submarine motion control, which reduces the control energy while ensuring the control effect. [ABSTRACT FROM AUTHOR]

We present a unique triangulation measurement of Strong Thermal Emission Velocity Enhancement (STEVE) observed on Sept 3rd, 2022, at Athabasca, Canada. Using two Digital single‐lens reflex (DSLR) color cameras with all‐sky fish‐eye lenses, we show the profile of STEVE altitude variation over time in 1 min resolution for the first time. We estimate the altitude variation of its visible purplish arc and green picket fence structures. We also compare the DLSR camera images with narrowband all‐sky images of an Optical Mesosphere Thermosphere Imager (OMTI) to see the correspondence of color camera images with 630 nm and OH‐band auroral/airglow emission images. The height of the purplish STEVE arc was stable at 150–170 km while present (∼0,546–0,633 UT), except for a short excursion to ∼200 km at 0,600 UT. The green picket fence structures appeared at 0,549 UT when the intensity of the STEVE arc started to intensify. They presented only for ∼7 min, and their altitude was steady at ∼110 km. The vertical movement of the STEVE arc to ∼200 km was found to be accompanied by the motion across the local magnetic field lines, suggesting a southward E × B drift underlying the westward ion drift. From the comparison with the OMTI images, we find that the purplish STEVE arc moved closer to the 630 nm arc in the all‐sky image when it rose to a higher altitude, indicating the occurrence of electron heating at a same or slightly higher altitude than the STEVE. Plain Language Summary: The Strong Thermal Emission Velocity Enhancement (STEVE) is a longitudinally extended purplish/mauve arc observed at subauroral latitudes, a region slightly equatorward of the typical aurora region. The morphological (shape and motion) characteristics of STEVE indicate that STEVE originates differently from typical aurora. Although it has been suggested that some chemical progresses are possibly triggering a STEVE, significant differences between observation and model still remain. The understanding of STEVE morphological characteristics, especially temporal features of STEVE development, will be helpful to improve our understanding about the STEVE generation. This paper presents a case study regarding the time variation of STEVE altitudes. The altitudes of STEVE are determined by triangulation using two color all‐sky cameras. We found that though the height of STEVE arc was stable for most of the time, it also rose and then descended for a short period. We also compared the images with camera detecting several wavelengths, and found that the STEVE moved closer to the red (wavelength: 630 nm, originating from oxygen) auroral arc in the all‐sky image when the STEVE elevated. This paper presents the first estimation of the temporal variation of STEVE altitudes. Key Points: First estimation of temporal variation of the altitudes of a Strong Thermal Emission Velocity Enhancement (STEVE)The estimated height of the STEVE arc was stable at ∼150–170 km for most of the time, except for a short elevation to ∼200 kmThe vertical motion of the STEVE arc entailed crossing of local magnetic field lines, and it moved closer to the 630 nm emission [ABSTRACT FROM AUTHOR]

Oceanic mesoscale eddies (with scale 101–102 km) and their submesoscale fine structures (with scale 100–101 km) can effectively induce vertical motions and bring nutrients into the oceanic euphotic layer, which leaves abundant footprints on the ocean surface chlorophyll distributions and have the potential to promote primary productivity of oceanic ecosystem. In return, these surface chlorophyll footprints observed by ocean color satellites can serve as a useful tool to reveal the spatial structures of mesoscale eddies and their submesoscale fine structures. By combining artificial intelligence (AI) algorithms to develop a series of identification strategies for typical surface chlorophyll patterns around mesoscale eddies, we find that over 20% of mesoscale eddy observations exhibit identifiable typical chlorophyll patterns, which tends to regulate an increase of the surface chlorophyll concentration within the corresponding eddies, especially enhancing by about 30% in nutrient‐restricted subtropical regions compared with the background values. Based on their geometric features, typical chlorophyll patterns are primarily classified as Core, Spiral, Tail, Ring, Loop, and Eye respectively by clustering algorithm. Further spatial‐spectral analysis found that the typical patterns on eddies exhibit a much steeper wave‐number spectral slope about −3, compared to the non‐typical distributions on eddies and the non‐eddy background distribution (about −2.7–−2.2). This implies that the occurrence of different typical chlorophyll patterns may correspond to specific mesoscale and submesoscale dynamic processes. Plain Language Summary: Mesoscale eddies and their submesoscale fine structures collectively play non‐negligible roles in sustaining nutrient supply and promoting productivity in the oceanic euphotic layer. Although submesoscale processes are believed to result in ageostrophic motions and allow forward oceanic energy cascade, the resolutions of traditional in‐situ ocean measurements and satellite altimetry observations are typically too coarse to resolve them. In this paper, we elaborate on artificial intelligence (AI) techniques to develop a series of typical surface chlorophyll pattern identification strategies. The AI framework automatically identified six types of typical chlorophyll patterns of mesoscale eddy, in the context of the generally comparable geometric characteristics that are potentially reflected from their underlined oceanic dynamics. Over 20% mesoscale eddy observations tend to exhibit identifiable typical chlorophyll patterns, which leads to a remarkable increase of surface chlorophyll concentration. The wave‐number spectrum of eddy‐induced typical patterns exhibit a significantly steeper slope, in comparison of the non‐typical distributions on eddies and the non‐eddy background distribution. Our results may help to establish parameterizations for the submesoscale processes of mesoscale eddies, or provide an observational baseline to verify high‐resolution physical‐biogeochemical coupled oceanic numerical models, or even improve the model simulations of oceanic primary productivity and carbon fixation capacity. Key Points: Six types of typical chlorophyll patterns on mesoscale eddies and their submesoscale fine‐structures are identified globally by artificial intelligence (AI) methodThe typical patterns tend to substantially enhance chlorophyll concentration of the corresponding eddiesThe wave‐number spectral slope of the typical chlorophyll pattern is significantly different from the background value [ABSTRACT FROM AUTHOR]

Two types of weather patterns with distinct locations of low-level cyclonic vorticity anomaly, referred to as Type 1 and Type 2, associated with local heavy summer rainfall over North China have been identified (Li et al., J Clim 37:2655–2672, 2024). However, their evolutions and underlying mechanisms were not investigated. In this study, we find that the large positive value of vorticity anomalies (LPV) for both types exhibit eastward intensification from their early to developing stages. Nonetheless, they follow distinct trajectories. For Type 1, the LPV takes a northern path, which is primarily attributed to the northward shift of the Western North Pacific subtropical high (WNPSH). The eastward development of LPV for Type 1 is significantly linked to vertical motion stretching. Quantitative examinations reveal that the dynamic forcing dominated by temperature advection mainly contributes to vertical motion at the early stage for Type 1, contributing 66.4%. The underlying mechanism involves significant southerly wind anomalies transporting warm flows northwards, promoting strong warm advection and enhancing upward motion and LPV development. In contrast, Type 2 follows a southern trajectory, which is affected by both the southward shift of WNPSH and baroclinic trough. For the eastward propagation of LPV for Type 2, it is also closely related to vertical motion stretching. Diagnosis reveals the diabatic forcing plays a more significant role on vertical motion at the early stage for Type 2, accounting for 59.7%. The nature is abundant moisture near the LPV facilitates strong diabatic forcing-induced upward motion. By the developing stage, the diabatic forcing becomes the main driver of vertical motion for both types. [ABSTRACT FROM AUTHOR]

The 400-degree-of-freedom deformed in-plane rigid-elastic-coupled tire model was enhanced by incorporating the vertical movement of the wheel as a rigid body. This refined model was then utilised to build the tire modal model. The tire modal model was developed to derive the transfer function (TF) covering a range of 0–300 Hz, which connects road irregularities as input to the contact patch and the wheel's vertical motion as output. The TF was operated under a quasi-static condition to obtain the tire's enveloping characteristics rolling over short wavelength obstacles as a direct function of vertical wheel displacement under varying contact patch length constraints. The tire modal model was combined with the quarter car model to analyse the vehicle's response when passing through short wavelength obstacles and random road profiles. This analysis was performed under varying load conditions represented by the contact patch length. The model and methodology demonstrated their effectiveness in handling rolling tires over short-wavelength obstacles and random road profiles. [ABSTRACT FROM AUTHOR]

Spring Central Asian precipitation (SCAP) holds significant implications for local agriculture and ecosystems, with its variability mainly modulated by El Niño–Southern Oscillation (ENSO). The ENSO–SCAP relationship has experienced pronounced interdecadal shifts, though mechanisms remain elusive. Based on observations and climate model simulations, these shifts may result from transitions in ENSO-induced meridional circulation and Rossby wave trains triggered by North Atlantic (NA) sea surface temperature (SST) anomalies. During high (low) correlation periods, ENSO induces strong (weak) vertical motion anomalies over Central Asia, while NA SST anomalies exert a weak (strong) counteracting effect, modulated by the Pacific decadal oscillation (PDO). In the positive (negative) phase of PDO, a slow (fast) decaying ENSO triggers a strong (weak) NA horseshoe-like SST anomaly in the post-ENSO spring, affecting the ENSO–SCAP relationship. Our study identifies a strengthening trend in the ENSO–SCAP relationship since the 2000s, indicating improved predictability for SCAP in recent decades. [ABSTRACT FROM AUTHOR]

The Southern Alps experiences rapid bedrock uplift and intense surface processes like erosion and deglaciation. We quantify how the erosion and deglaciation contribute to the ongoing vertical motions using geophysical models. The erosional unloading uplift is found to be 0.5–1.5 mm/yr throughout the central Southern Alps, whereas the recent deglaciation may locally produce uplift up to 1–3 mm/yr. The estimated unloading uplift accounts for 10%–40% of the GNSS‐observed uplift. After correcting the unloading uplift, the GNSS‐observed uplift can be explained by about 4–6 mm/yr dip‐slip motion on the Alpine fault, which is 10%–50% below previous geodetic estimates. Hence, unloading uplift must be evaluated when interpreting geodetic observations in tectonically active mountain ranges subjected to intense surface processes. Plain Language Summary: As surface processes such as erosion and deglaciation abrade mountain ranges, the removal of mass relieves the mass loading on the Earth's surface, turning on the solid Earth rebound where the focused mass removal has/had been operating. This rebound, known as unloading uplift, may reach up to 3–5 mm/yr in the Southern Alps in New Zealand where surface processes such as erosion and deglaciation are rapid and intense. This unloading uplift can account for about 10%–40% of the geodetically observed ongoing uplift. Hence, we must correct the unloading uplift to get reliable tectonic interpretations of the geodetically observed uplift. Key Points: Unloading uplift caused by erosion is currently about 0.5–1.5 mm/yr throughout the central Southern AlpsAdditional uplift caused by deglaciation since the end of the Little Ice Age is about 1–3 mm/yr around the Aoraki/Mount Cook, the highest peak of the Southern AlpsCorrecting the unloading uplift caused by surface processes lowers estimates of dip‐slip motion for the Alpine fault by 1–3 mm/yr [ABSTRACT FROM AUTHOR]

Gaseous, disc–halo interfaces are shaped by processes that are critical to galaxy evolution, including gas accretion and outflows. Extraplanar diffuse ionized gas (eDIG) layers are characterized by scale heights that largely exceed those predicted by their temperature, suggesting the presence of turbulent energy injection from star-formation feedback. However, the origin of this large-scale height remains uncertain. To explore the connection between eDIG and star-forming discs, we present a spatially resolved case study of a nearby pair of sub- |$L_*$|⁠ , intermediately inclined disc galaxies NGC 3511/3513. We decompose optical nebular lines observed using long-slit spectroscopy into narrow and broad velocity components. In NGC 3511, the broad component has three distinctive characteristics in comparison to the narrow component: (1) significantly higher velocity dispersions (a median |$\langle \sigma \rangle _{\text{Broad}} = 24$|  km s |$^{-1}$| compared to |$\langle \sigma \rangle _{\text{Narrow}} = 13$|  km s |$^{-1}$|⁠), (2) elevated [N  ii ] |$\lambda$| 6583/H |$\alpha$| and [S  ii ] |$\lambda$| 6716/H |$\alpha$| line ratios, and (3) a rotational velocity lag. These characteristics support the origin of the broad component in an extraplanar, gaseous disc. In NGC 3513, the broad component reveals disc–halo circulation via localized outflows at radius |$\lesssim 1$|  kpc. For NGC 3511, we test a vertical hydrostatic equilibrium model with pressure support supplied by thermal and turbulent motions. Under this assumption, the eDIG velocity dispersion corresponds to a scale height |$h_{z} \gtrsim 0.2 - 0.4$|  kpc at |$R = 3 - 5$|  kpc, a factor of a few above the thermal scale height (⁠|$h_{z} \lesssim 0.1$|  kpc). This highlights the importance of turbulent motions to the vertical structure of the gaseous, disc–halo interface. [ABSTRACT FROM AUTHOR]

Summer drought over northern Asia (NA) seriously threatens the local fragile ecological environment and social economy development. In this study, using the standardized precipitation evapotranspiration index (SPEI), we first identify the dominant modes of interannual variability in summer drought condition over NA and then explore the atmospheric patterns responsible for the formation of the modes. The results show that the first empirical orthogonal function (EOF1) mode of summer SPEI over NA exhibits a meridional dipole pattern, which is influenced primarily by the polar–Eurasian teleconnection (POL) and circumglobal teleconnection (CGT) patterns. Under the influence of negative POL and positive CGT patterns, there is an anomalous anticyclone (cyclone) over northwestern Siberia (Lake Baikal to Northeast China). Such atmospheric circulations lead to meridional dipole patterns in air temperature, moisture condition, vertical motion, and cloud cover over NA, favoring decreased (increased) precipitation and increased (decreased) potential evapotranspiration over northern (southern) NA, finally contributing to the formation of EOF1. The second EOF (EOF2) shows an approximate zonal dipole pattern, which is influenced by the British–Baikal Corridor (BBC) and Scandinavia (SCA) teleconnection patterns. The positive BBC and SCA patterns can lead to an anomalous anticyclone over the Ural Mountains and a cyclone over Lake Baikal. Such atmospheric circulations result in a zonal dipole pattern in precipitation and potential evapotranspiration over NA through changing the local moisture condition, air temperature, and radiation, consequently favoring the formation of EOF2. Fitting analysis indicates that the aforementioned atmospheric factors can explain 76% (55%) of the interannual variability of EOF1 (EOF2). [ABSTRACT FROM AUTHOR]

A novel wave energy harvester (WEH) that can recover energy in the direction of heave, sway, and surge is designed under the background of low recovery efficiency and complex installation of the existing wave energy harvester. The harvester consisted of four main components: energy input module, energy transfer module, energy conversion module, and energy store module. In the paper, to convert more wave energy into electrical energy and improve the energy conversion efficiency of WEH, the motion transfer module is divided into vertical and horizontal motion transfer modules, which are used to harvest vertical and horizontal wave energy, respectively. The vertical motion transfer module combined with the ball screw structure, planetary gear structure, and one-way gear units ensure the generator has high speed. The horizontal motion transfer module is mainly composed of three uniformly distributed one-way gear units, ensuring collect the wave energy in all horizontal directions. The dynamic model of the harvester is established, and the simulation experiment is carried out under wave conditions with periods of 2 s, 2.5 s, and 3 s, respectively. The simulation results show that when the wave period is 2 s, 2.5 s, and 3 s, the corresponding energy conversion efficiency of the WEH is 66.7%, 60.9%, and 57.1%, respectively. The proposed study provides a theoretical reference for modeling similar WEHs and can effectively balance energy supply and demand and further support the global agenda of UN-2030 for sustainable development, especially SDG-7. [ABSTRACT FROM AUTHOR]

Coastal areas are currently exposed to numerous hazards exacerbated by climate change, including erosion, flooding, storm surges, and other sea level rise phenomena. Mediterranean countries, in particular, are facing a constant shrinking of coastal areas. This region also hosts significant cultural heritage assets, including several UNESCO World Heritage Sites. The present research demonstrates a methodological approach to assess the current and future exposure of Mediterranean coastal areas and heritage assets to Sea Level Rise using open access data regarding elevation, vertical ground motion, and Sea Level Change factors (e.g., ice sheets, glaciers, etc.). The future projections regard 2050 and 2100 and are based on RCP scenarios 2.6, 4.5 and 8.5. The datasets used include Copernicus GLO-30 DSM, the European Ground Motion Service's dataset on Vertical Ground Motion, the Sea Level Change Projections' Regional Dataset by NASA, and a hybrid coastline dataset created for the present research purposes to assist in delineating the study area. The research results demonstrate that Greece, Italy, and France's mainland and cultural heritage assets already face SLR-related hazards but are expected to be further exposed in the future, always taking into consideration the high level of uncertainty regarding SLR projections and RCP scenarios' hypotheses. [ABSTRACT FROM AUTHOR]

This study verifies the capability of evolutionary circulation to characterize the movement of rain belt based on Self-Organizing Map (SOM) and further explores the interdecadal variation of rain belt's northward advancement during flood season in eastern China. The results show that the evolving path of circulation patterns can effectively describe the trajectory of rain belt's movement with a significant correlation coefficient of 0.91. By employing the time required for circulation evolution to represent the velocity of rain belt's movement, the northward velocity of rain belt emerges interdecadal shifts around the mid-late1970s and the late 1990s, which is affected by the sea surface temperature anomaly of Pacific Decadal Oscillation (PDO) pattern. During negative PDO phases, the warming of western North Pacific and the cooling in equatorial middle-east Pacific trigger the northward westerly jet and Western Pacific Subtropical High, leading to the northward vertical upward motion. This configuration encourages the circulation pattern corresponding to Yangtze-Huaihe River basin rain belt to transfer to that representing more precipitation in North and Northeast China, resulting in the accelerated northward advance of rain belt. Conversely, during positive PDO phases, the moisture brought by westward subtropical high and upward motion driven by the southward upper jet stream increase the likelihood of persistent precipitation in Yangtze-Huaihe River Basin, slowing the advancement of rain belt. During the phase transition of PDO, the northward leap of circulation systems in July has been proved to play a pivotal role in the interdecadal variation of rain belt's overall advancing velocity. [ABSTRACT FROM AUTHOR]