Dynamics of Atmospheres and Oceans最新文献_第5页

Interannual rainfall variability in Northeast Brazil influenced by Pacific and Atlantic climate modes 太平洋和大西洋气候模式对巴西东北部年际降水变异的影响

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-12-01 Epub Date: 2025-09-06 DOI: 10.1016/j.dynatmoce.2025.101596

Evelin Landin Vitorio , Thiago Silva , Isabelle Vilela , Edvânia Santos , Doris Veleda

Northeast Brazil (NEB) is a climatically diverse region that includes semi-arid zones highly vulnerable to droughts and coastal areas frequently affected by extreme rainfall and flooding. These extremes pose significant challenges to water security, agriculture, and infrastructure. Effective climate forecasting in NEB requires a comprehensive understanding of multi-basin interactions, as they play a pivotal role in shaping regional precipitation patterns. Monitoring the simultaneous influences of both the Pacific and Atlantic climate indices is crucial for improving prediction accuracy, given the complex and interconnected nature of ocean-atmosphere dynamics that affect the region. This study investigates 75 years (1948–2022) of Pacific and Atlantic climate modes and their impact on NEB precipitation. Composite analyses were conducted using the 25th and 75th percentiles of sea surface temperature (SST) anomalies to define the warm and cold phases of each climate index. The results show distinct rainfall patterns across the NEB, with delayed responses to different oceanic indices. In Northern NEB (NNEB), the positive phases of Atlantic Meridional Mode (AMM) and El Niño-Southern Oscillation (ENSO) reduce rainfall, while the South Atlantic Ocean Dipole (SAOD) and Tropical South Atlantic (TSA) increase it. In Northern Eastern NEB (ENEBn), the positive phases of the AMM and Niño 1 + 2 decrease rainfall, while the South Atlantic Warm Pool (SAWP) enhances it. Simultaneous influences of the Pacific and Atlantic indices are associated with intense precipitation or drought events.

巴西东北部（NEB）是一个气候多样化的地区，包括极易受到干旱影响的半干旱地区和经常受到极端降雨和洪水影响的沿海地区。这些极端天气对水安全、农业和基础设施构成了重大挑战。在东北地区进行有效的气候预报需要对多流域相互作用有全面的了解，因为它们在形成区域降水模式方面起着关键作用。考虑到影响该区域的海洋-大气动力学的复杂性和相互关联性，监测太平洋和大西洋气候指数的同时影响对提高预测精度至关重要。本文研究了太平洋和大西洋的75年（1948-2022）气候模式及其对东北地区降水的影响。利用海表温度（SST）异常的第25和75百分位进行复合分析，确定了各气候指数的暖相和冷相。结果表明，整个东北地区的降雨模式不同，对不同的海洋指数有延迟响应。在北东太平洋（NNEB），大西洋经向模态（AMM）和厄尔尼诺Niño-Southern涛动（ENSO）的正相位减少了降水，而南大西洋偶极子（SAOD）和热带南大西洋（TSA）增加了降水。东北东北地区（ENEBn） AMM和Niño 1 + 2正相减少降水，而南大西洋暖池（SAWP）增强降水。太平洋和大西洋指数的同时影响与强降水或干旱事件有关。

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引用次数: 0

Assessment of precipitation reanalysis product ERA5 on summer extreme precipitation in the Yellow River Basin 降水再分析产品ERA5对黄河流域夏季极端降水的评价

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-12-01 Epub Date: 2025-10-15 DOI: 10.1016/j.dynatmoce.2025.101603

Guangyu Lan, Yun Liang, Yucheng Ma

Based on the rain gauge-based gridded precipitation data from the CN05.1 dataset, the applicability of ERA5 in representing summer extreme precipitation in the Yellow River Basin (YRB) was evaluated from three aspects: climatology, deterministic and probabilistic assessment, and the spatiotemporal characteristics of the leading modes. The results showed that the ERA5 reanalysis demonstrates capability in capturing climatological characteristics of precipitation and extreme precipitation over the YRB, albeit with intensified climatological means and standard deviations, coupled with opposing linear trends. In terms of interannual variability, its precipitation estimates demonstrate notably higher accuracy in the recent decade compared to earlier periods. Deterministic evaluation reveals superior representation of general precipitation compared to intense precipitation. Probabilistic assessments indicate that uncertainties predominantly originate from the upper and northern middle reaches of the YRB, accompanied by systematic biases in probabilistic estimations of increased extreme precipitation amounts and decreased extreme precipitation days. While ERA5 successfully reproduces spatial patterns of the first two dominant modes of precipitation and extreme precipitation across the YRB, it amplifies anomalous signals. ERA5 accurately simulates interannual cycles associated with the first mode, but introduces spurious decadal signals in the second mode's temporal evolution.

基于CN05.1雨量计格点降水资料，从气候学、确定性和概率评估以及主要模态的时空特征三个方面，对ERA5表征黄河流域夏季极端降水的适用性进行了评价。结果表明，ERA5再分析具有较强的气候平均值和标准差，并伴有相反的线性趋势，但能较好地捕捉到青藏高原降水和极端降水的气候特征。就年际变率而言，其降水估计在最近十年中显示出与早期相比显著更高的准确性。确定性评价表明一般降水比强降水具有更好的代表性。概率评估表明，不确定性主要来自长江三角洲中上游和中北部，在极端降水量增加和极端降水日数减少的概率估计中存在系统偏差。虽然ERA5成功地再现了YRB前两种主要降水模态和极端降水模态的空间格局，但它放大了异常信号。ERA5准确地模拟了与第一模态相关的年际周期，但在第二模态的时间演变中引入了伪年代际信号。

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引用次数: 0

Non-Darcy and Joule heating in MHD convective micropolar heat transfer flow over a stretchy cooling sheet with variable heat gain 可变热增益的弹性冷却片上MHD对流微极换热流动的非达西和焦耳加热

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-12-01 Epub Date: 2025-11-14 DOI: 10.1016/j.dynatmoce.2025.101615

T. Venu , MD. Shamshuddin , S.O. Salawu , Subhajit Panda

The research intends to characterize the thermal performance in micropolar fluid flows on a vertically elongated porous sheet with buoyancy-induced forces. The model incorporates the distribution of a non-uniform heat source/sink, Darcy dissipation, and the fluid flows across a porous substrate. The mathematical problem is non-dimensionalized under the similarity transformation approach as a coupled set of ordinary differential equations from the principal partial differential equations. A similarity transformation is done on the model to reduce it to ordinary differential equations are subsequently solved by the Runge-Kutta 4th order method utilizing the shooting scheme to evaluate numerical findings of dependent quantities of physical importance through MATLAB. The impact of varied parameters on the fluid momentum, angular momentum, and energy was analyzed and shown graphically. The key results revealed that the Darcy porosity meaningfully affects the momentum and thermal boundary layer. This brings about a higher wall shear stress. Micropolar fluid term contributes significantly to the microrotation and shear stress distributions development. Boundary convective conditions spur a nonlinear thermal distribution response that is sensitive to the Biot number variation for an effective boundary thermal exchange.

本研究旨在利用浮力表征微极流体在垂直细长多孔板上的热性能。该模型结合了非均匀热源/热源的分布、达西耗散和流体流过多孔基板的情况。在相似变换方法下，将数学问题无量纲化，转化为由主偏微分方程组成的常微分方程的耦合集。对模型进行相似变换，将其简化为常微分方程，然后利用四阶龙格-库塔法求解，利用射击格式通过MATLAB对物理重要性相关量的数值结果进行评价。分析了不同参数对流体动量、角动量和能量的影响，并用图形表示。关键结果表明，达西孔隙度对动量和热边界层有重要影响。这导致了较高的壁剪应力。微极流体项对微旋转和剪应力分布的发展有重要影响。为了实现有效的边界热交换，边界对流条件激发了对Biot数变化敏感的非线性热分布响应。

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引用次数: 0

Influence of Cattaneo-Christov radiative heat flux in magnetized flow performance of three different materials with variable constraints 变约束条件下三种不同材料磁化流性能的影响

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-12-01 Epub Date: 2025-10-21 DOI: 10.1016/j.dynatmoce.2025.101608

Muhammad Yasir , Karim Choubani , Muhammad Naveed Khan , Mohammed A. Almeshaal , Mohamed Hussien

The phase change transition aspects in various non-Newtonian fluid flow analyses have been examined, motivated by the progressive relaxation properties of flow and its applied benefits in the rheological characterization of various dynamic fluids. A thermal radiation-based mechanism with mass diffusion process and magnetized flow properties of three significant models of micropolar fluid, Casson fluid, and Maxwell fluid are briefly analyzed in this study. The melting heat transport phenomenon of all fluids is briefly explained with variables physical characteristics based on exponential function. By taking the medium of a stretched sheet, the radiative flow problem is scrutinized under the theory of boundary layer. Moreover, significant theory of Cattaneo Christov is imposed through modified Fourier and Ficks laws to discuss the thermal process and mass diffusion phenomenon. The physical factor of viscous dissipation along with thermal radiation is also incorporated. The velocity slip constraint is taken on the boundary surface. By taking both weak and strong concentrations of microparticles, the physical characteristics of micropolar fluid along with other Maxwell fluid and Casson fluid are graphically exhibited through bvp4c technique in MATLAB package. This comparative study yields the fact that radiation parameter significantly upsurges the temperature field of Casson fluid as compared to other fluids.

由于流动的渐进弛豫特性及其在各种动态流体流变学表征中的应用优势，研究了各种非牛顿流体流动分析中的相变方面。本文简要分析了三种重要的微极流体、Casson流体和Maxwell流体模型的热辐射质量扩散机理和磁化流动特性。以指数函数为基础，用变量物理特性对所有流体的熔融传热现象作了简要解释。以被拉伸薄片为介质，在边界层理论下研究了辐射流动问题。此外，通过修正傅里叶定律和菲克斯定律，引入了Cattaneo Christov的重要理论来讨论热过程和质量扩散现象。此外，还考虑了伴随热辐射的粘性耗散的物理因素。在边界面上取速度滑移约束。通过MATLAB软件包中的bvp4c技术，以微极流体以及其他麦克斯韦流体和卡森流体的弱、强浓度为条件，图形化地展示了微极流体的物理特性。对比研究发现，与其他流体相比，卡森流体的辐射参数使其温度场显著升高。

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引用次数: 0

Energy transport in ternary hybrid nanofluid with variable thermal conductivity under the combined effects of electroviscous, electric potential, and heat generation 电粘性、电势和产热共同作用下变导热三元杂化纳米流体中的能量输运

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-12-01 Epub Date: 2025-11-26 DOI: 10.1016/j.dynatmoce.2025.101619

Shafiq Ahmad , Aamir Abbas Khan , Muhammad Naveed Khan , Salah Knani , N. Ameer Ahammad , Ibrahim E. Elseesy

This article uses squeezing plates containing ternary hybrid nanofluid to scrutinize the behavior of transient electroviscous fluid flow with an induced magnetic field. By dissolving the constituents, such as silicon carbide, aluminum oxide, and multiwall carbon nanotubes, in a base fluid of water, a ternary hybrid nanofluid

M W C N T + A l_{2} O_{3} + S i C / H_{2} O

was created. The current work aims to increase the energy transfer rate for technical and industrial applications. In the presence of heat generation, thermal radiation, and varying thermal conductivity, fluid flow exhibits its thermal behavior. Through the use of similarity substitution, an ordinary differential equation (ODE) set is obtained from a system of partial differential equations (PDEs) representing the ternary hybrid nanofluid flow. After that, using the bvp4c approach, the dimensionless ordinary differential equations in the nonlinear set are solved. On ternary hybrid nanofluid (

M W C N T + A l_{2} O_{3} + S i C / H_{2} O

) and unary nanofluid (

A l_{2} O_{3} / H_{2} O

), the graphical and numerical results are found against the many parameters. The findings show that, in comparing to unary nanofluids, ternary hybrid nanofluids have a greater impact on heat transfer rate owing to the fact that the inclusion of nanofluids to the base fluid intensifies heat transport rate.

本文利用含三元杂化纳米流体的挤压板研究了瞬态电粘性流体在感应磁场作用下的流动行为。通过将碳化硅、氧化铝和多壁碳纳米管等成分溶解在水的基液中，形成了MWCNT+Al2O3+SiC/H2O三元混合纳米流体。目前的工作旨在提高技术和工业应用的能量转移速度。在热产生、热辐射和热导率变化的情况下，流体流动表现出其热行为。利用相似代入的方法，从三元混合纳米流体流动的偏微分方程组中得到一个常微分方程集。在此基础上，利用bvp4c方法对非线性集合中的无量纲常微分方程进行求解。对三元杂化纳米流体（MWCNT+Al2O3+SiC/H2O）和一元纳米流体（Al2O3/H2O），在多种参数下得到了图形和数值结果。研究结果表明，与一元纳米流体相比，三元混合纳米流体对传热速率的影响更大，这是由于纳米流体与基流体的包裹体增强了传热速率。

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引用次数: 0

High-resolution simulations of tropical cyclone rapid intensity variability: The sensitivity to microphysics and planetary boundary layer scheme combinations 热带气旋快速强度变化的高分辨率模拟：对微物理和行星边界层方案组合的敏感性

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-09-01 Epub Date: 2025-07-25 DOI: 10.1016/j.dynatmoce.2025.101583

Chen Chen , Jiangnan Li

The rapid intensification (RI) or rapid weakening (RW) of tropical cyclones (TC) is a challenging problem for forecasters. In numerical models, the selection of parameterization schemes, such as microphysics (MP) schemes and planetary boundary layer (PBL) schemes, introduces significant uncertainties in predicting TC intensity. The mechanisms behind the combining effects of different parameterization schemes on TC rapid intensity changes remain unclear. This study uses the Weather Research and Forecasting (WRF) model with various combinations of the WSM6, WSM7, Goddard MP schemes, and the YSU, QNSE and BouLac PBL schemes to conduct multiple high resolution simulation experiments on the TC Mujigae (2015), which experienced both RI and RW processes. The results show that the amount and radial distribution of latent heat release from the early stage of the simulation have close ties with the structure and intensity of the TC, while the surface enthalpy flux plays a relatively secondary role in TC intensity changes. When substantial latent heat release occurs closer to the TC center at the pre-RI period, the eyewall convection intensifies, leading to a higher convective burst (CB) index, faster formation of a compact structure, greater tangential kinetic energy, and RI. An ample surface enthalpy flux is not the key factor triggering the RI process in the experiments. It does not enable the failed group to simulate RI, but it can enhance the intensity in the successful group. The TCs that simulate RI show significantly reduced latent heat and energy supply from the boundary layer after landfall, leading to the RW process. Compared with the actual TC track, intensity, precipitation, brightness temperature, and reflectivity, the Goddard_YSU combination is the best among our experiments, accurately simulating RI and replicating RW. Latent heat from microphysics and the CB index correlate more strongly with TC intensity variations than surface enthalpy flux.

热带气旋的快速增强（RI）或快速减弱（RW）是一个具有挑战性的问题。在数值模式中，参数化方案的选择，如微物理（MP）方案和行星边界层（PBL）方案，在预测TC强度时引入了很大的不确定性。不同参数化方案联合作用对TC快速强度变化的机制尚不清楚。本文利用WSM6、WSM7、Goddard MP方案和YSU、QNSE和BouLac PBL方案组合的WRF模式，对同时经历了RI和RW过程的TC Mujigae（2015）进行了多次高分辨率模拟试验。结果表明：模拟初期的潜热释放量和径向分布与TC的结构和强度密切相关，而表面焓通量对TC强度变化的影响相对次要。当大量潜热释放发生在离TC中心较近的位置时，眼壁对流增强，导致对流爆发（CB）指数更高，致密结构形成更快，切向动能更大，RI更高。在实验中，充足的表面焓通量并不是触发RI过程的关键因素。它不能使失败组模拟RI，但可以增强成功组的强度。模拟RI的TCs显示，登陆后边界层的潜热和能量供应显著减少，导致RW过程。与实际的TC轨迹、强度、降水、亮度温度和反射率相比，godddard_ysu组合是我们实验中最好的，可以准确地模拟RI和复制RW。与表面焓通量相比，微物理潜热和CB指数与TC强度变化的相关性更强。

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引用次数: 0

Enhancing groundwater quality index prediction in data-scarce regions: Application of advanced artificial intelligence models in Nagaland, India 加强数据稀缺地区地下水质量指数预测：先进人工智能模型在印度那加兰邦的应用

IF 1.9 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-09-01 Epub Date: 2025-07-11 DOI: 10.1016/j.dynatmoce.2025.101579

Subhrajyoti Deb

The Groundwater Quality Index (GQI) serves as a critical benchmark for assessing the long-term impacts of anthropogenic activities and natural processes on groundwater quality. However, calculating GQI from irregular datasets containing multiple parameters is often prone to errors. Despite growing interest in machine learning for water quality assessment, very few studies have explored groundwater quality prediction in data-scarce topographically complex regions. Moreover, limited efforts have been made to compare a wide range of Artificial Intelligence (AI) models under variable input scenarios using actual field data. To address this research gap, this study employs eight advanced AI models—Artificial Neural Network (ANN), Autoregressive Model (AR), Locally-weighted Linear Regression (LLR), M5P tree, Multiple Linear Regression (MLR), Random Forest (RF), Random Subspace (RS), and Support Vector Machine (SVM)—to predict GQI in Nagaland, a data-scarce hilly region in northeastern India. The research focuses on identifying an optimal subset regression for two scenarios: one optimizing GQI computation time by incorporating all water quality parameters, and the other exploring variations using the most sensitive parameters. Key findings reveal strong linear relationships between hydro-chemical parameters and GQI, with significant correlations such as Na⁺ with TDS (0.936) and Mg²⁺ with GQI (0.922). Sensitivity analysis identifies TDS and TH as primary determinants of GQI. Among the models, MLR achieves higher accuracy in the first scenario, with performance metrics of R (correlation coefficient) = 0.9999, MAE (Mean Absolute Error) = 0.0001, and RMSE (Root Mean Square Error) = 0.0002 %. In contrast, ANN performs better in the second scenario, with MAE = 2.4718, R = 0.9977, and RAE = 3.5463 %. These results highlight the efficacy of advanced AI models in enhancing GQI prediction accuracy, particularly in data-scarce regions like Nagaland.

地下水质量指数（GQI）是评价人类活动和自然过程对地下水质量长期影响的重要基准。然而，从包含多个参数的不规则数据集计算GQI往往容易出错。尽管人们对水质评估的机器学习越来越感兴趣，但很少有研究在数据稀缺的地形复杂地区探索地下水质量预测。此外，在使用实际现场数据的可变输入场景下，对各种人工智能（AI）模型进行比较的努力有限。为了弥补这一研究空白，本研究采用了八种先进的人工智能模型——人工神经网络（ANN）、自回归模型（AR）、局部加权线性回归（LLR）、M5P树、多元线性回归（MLR）、随机森林（RF）、随机子空间（RS）和支持向量机（SVM）——来预测印度东北部数据稀缺的山区那加兰邦的GQI。研究的重点是确定两种情况下的最优子集回归：一种是通过合并所有水质参数来优化GQI计算时间，另一种是使用最敏感的参数来探索变化。关键发现表明，水化学参数与GQI之间存在较强的线性关系，其中Na+与TDS（0.936）、Mg2+与GQI（0.922）的相关性显著。敏感性分析表明TDS和TH是GQI的主要决定因素。其中，MLR模型在第一种场景下的准确率较高，其性能指标R（相关系数）= 0.9999，MAE（平均绝对误差）= 0.0001，RMSE（均方根误差）= 0.0002 %。相比之下，ANN在第二种场景下表现更好，MAE = 2.4718,R = 0.9977,RAE = 3.5463 %。这些结果突出了先进的人工智能模型在提高GQI预测准确性方面的功效，特别是在那加兰邦等数据稀缺地区。

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引用次数: 0

Long waves propagating at the interface between an inviscid subsonic gas and an Oldroyd-B liquid flowing down an oblique substrate 在无粘性亚音速气体和沿斜基底向下流动的Oldroyd-B液体之间的界面上传播的长波

IF 2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-09-01 Epub Date: 2025-08-14 DOI: 10.1016/j.dynatmoce.2025.101587

Ahmed Assaf , Sameh A. Alkharashi

The present problem investigated the dynamics of a fine layer for Oldroyd-B liquid moving down an inclined plate subject to a subsonic gas. Solitons propagating at such an interface were investigated to enhance the work novelty. The technique of thin film was employed to get an evolution relation that prescribes such an interface shape along time increase. The treatment based on linear theory was employed. The stability might be enhanced by means of increasing gas thickness and surface tension or decreasing the perturbation coefficient of gas. The viscosity ratio, Reynolds number, and relaxation time had a dual impact. The presence of moving solitons was illustrated under certain conditions for such a film. The nonlinear expectations could be more precision to prescribe the instability compared to the linear one. The present results did give an acceptable practical implementation of potential applications besides facilitating the way to precise numerical simulation.

本问题研究了在亚音速气体作用下，Oldroyd-B液体沿倾斜板向下运动的细层动力学。为了提高工作的新颖性，研究了在这种界面上传播的孤子。利用薄膜技术得到了这种界面形状随时间增加的演化关系。采用基于线性理论的处理方法。通过增加气体的厚度和表面张力或减小气体的微扰系数可以提高其稳定性。黏度比、雷诺数和弛豫时间具有双重影响。运动孤子的存在是在这种电影的特定条件下说明的。与线性期望相比，非线性期望能更精确地描述不稳定性。本文的结果除了为精确的数值模拟提供了途径外，还为潜在的应用提供了可接受的实际实现。

引用次数: 0

How does HAIKUI remnant produce heavy precipitation in 2023 2023年海葵残区如何产生强降水

IF 1.9 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-09-01 Epub Date: 2025-05-24 DOI: 10.1016/j.dynatmoce.2025.101563

Ping Ye , Yuan Zhu , Haoya Liu

In 2023, HAIKUI's prolonged remnant caused exceptional destruction, exposing critical gaps in understanding tropical cyclone (TC) remnant dynamics. While existing studies have documented decay processes of TC remnant, systematic analyses of stage-dependent moisture transport remain lacking. This study combines multi-source data to reveal HAIKUI remnant's structural evolution, moisture trajectories, and precipitation drivers. During the persistence of the HAIKUI remnant, the mountain ranges together with environmental airflow played a pivotal role in isolating the low-pressure system, maintaining its coverage largely unchanged. Based on temporal variations, the lifecycle of HAIKUI remnant can be segmented into three distinct stages: the moving stage, the charging stage, and the separating stage. In the moving stage, the center of HAIKUI remnant and the corresponding rain band gradually shifted westward, exhibiting both barotropic and baroclinic characteristics. The charging stage marked a period where HAIKUI remnant's center hovered over Guangxi Province. The dominance of barotropic structure enhanced moisture convergence, generating an arc-shaped heavy rainfall belt. In the separating stage, the mid- and low-level centers of HAIKUI remnant moved toward opposing directions, resulting in a primarily baroclinic circulation structure. The convergence of cold and warm air led to precipitation in the Pearl River Delta region. The findings highlighted the impact of topography and moisture transport on the evolution and precipitation of TC remnant, offering valuable insights for future predictions of precipitation- and flood-related disasters caused by such remnants.

2023年，海葵的长时间残余造成了异常的破坏，暴露了对热带气旋（TC）残余动力学的理解的关键空白。虽然现有的研究已经记录了TC残余物的衰变过程，但仍然缺乏对阶段相关水分输送的系统分析。本研究结合多源资料揭示了海葵残片的结构演化、水汽运动轨迹和降水驱动因素。在海葵残余物持续期间，山脉和环境气流对低压系统起到了隔离作用，使其覆盖范围基本保持不变。根据时间变化特征，将海葵残体的生命周期划分为三个阶段：移动阶段、充装阶段和分离阶段。在移动阶段，海葵残余物中心和相应的雨带逐渐向西移动，呈现正斜压特征。冲锋阶段标志着海葵残余中心在广西上空盘旋的时期。正压结构的优势增强了水汽辐合，形成弧形强雨带。分离阶段，海葵残余物中低层中心向相反方向移动，形成以斜压为主的环流结构。冷暖空气辐合导致珠江三角洲地区出现降水。这些发现突出了地形和水分输送对TC残余物演化和降水的影响，为未来预测由这些残余物引起的降水和洪水相关灾害提供了有价值的见解。

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引用次数: 0

Dynamic and thermodynamic characteristics of the Bay of Bengal cyclones during 2001–20 and impact of scatterometer winds through composite analysis 2001 - 1990年孟加拉湾气旋的动力热力特征及散射计风的影响

IF 1.9 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Dynamics of Atmospheres and Oceans

Pub Date : 2025-09-01 Epub Date: 2025-06-03 DOI: 10.1016/j.dynatmoce.2025.101564

Ipshita Bhasi , Jagabandhu Panda , Subodh Kumar , Debashis Paul , Ashish Routray

This study comprehensively investigates the dynamic, and thermodynamic characteristics associated with pre-monsoon and post-monsoon tropical cyclones (TCs) over the Bay of Bengal during 2001–20. For this purpose, numerical simulations using Weather Research and Forecasting model (called CTRL) and the outputs with assimilation through three-dimensional variational data assimilation techniques (called DA) are used. The DA experiments considered modified initial conditions that are generated by employing assimilated scatterometer winds. Accordingly, a total of 74 model simulations are carried out for 37 TCs categorized as Cyclonic Storm (CS), Severe Cyclonic Storm (SCS), and Highly Intensified Cyclonic Storm (HICS), for preparing the composites. Composite analysis involving different category TCs is performed, where the simulated results are compared against India Meteorological Department observations and the Indian Monsoon Data Assimilation and Analysis (IMDAA). The comparison provides an insight regarding the model performance, where DA demonstrates improved estimation of maximum sustained wind, minimum sea level pressure and cyclone track. The seasonal variations of the dynamic characteristics consisting of vertical wind shear, vorticity, and tangential and radial winds are found to strengthen along with TC intensity. Also, an increase in the rate of convergence supported by well-defined wind fields is realized at the TC center. In most instances, both experiments demonstrate similar trends, but DA exhibits improvement in the estimations, specifically for SCS and HICS categories. However, a limited impact of scatterometer wind data assimilation is realized on the dynamic behavior of CS category TCs. The impact is also found to be limited on the thermodynamic properties of all three categories, although the seasonal variation reveals a consistent increasing trend of temperature anomalies with TC intensity, indicating an association with the intensification process.

本文研究了2001 - 2010年孟加拉湾季风前和季风后热带气旋（TCs）的动力学和热力学特征。为此，使用天气研究与预报模式（CTRL）的数值模拟和通过三维变分数据同化技术（DA）同化的输出。数据同化试验考虑了利用同化散射计风产生的修正初始条件。因此，为了制备复合材料，共对37种不同类型的气旋风暴（CS）、强气旋风暴（SCS）和高度强化气旋风暴（HICS）进行了74次模式模拟。将模拟结果与印度气象部门的观测和印度季风资料同化与分析（IMDAA）进行了比较，并对不同类型的TCs进行了综合分析。比较提供了关于模式性能的见解，其中DA显示了对最大持续风，最小海平面压力和气旋路径的改进估计。垂直风切变、涡度、切向风和径向风的动力特征随TC强度的增加而增强。此外，在明确的风场支持下，辐合速度也有所提高。在大多数情况下，两个实验都显示出类似的趋势，但数据分析在估计方面表现出改进，特别是对SCS和HICS类别。然而，散射计风资料同化对CS类TCs的动力特性影响有限。尽管季节变化显示温度异常随TC强度的增加呈一致的增加趋势，表明温度异常与TC强度的增强过程有关，但对所有三类的热力学性质的影响也有限。

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引用次数: 0