Pub Date : 2025-12-16DOI: 10.1016/j.dynatmoce.2025.101633
Maham Mujahid , Mounirah Areshi , Zaheer Abbas , Muhammad Yousuf Rafiq , Ibrahim E. Elseesy
This study conducts an analytical examination of thermo-magneto-hydrodynamic slip flow of a Jeffery fluid through a porous wavy curved channel. The energy equation incorporates the effects of thermal radiation along with heat generation and absorption mechanisms. By formulating the governing equations in curvilinear coordinates and applying a regular perturbation method, closed-form expressions for the velocity, temperature, skin-friction coefficient, and Nusselt number are obtained. The parametric investigation indicates that both channel curvature and porous permeability enhance fluid transport, while the applied magnetic field suppresses motion. Thermal radiation notably intensifies heat transfer and facilitates bolus formation by decreasing the effective viscosity and augmenting buoyancy effects. Overall, the findings provide a useful theoretical basis for the design and optimization of advanced thermal management systems, polymer processing technologies, and MHD-based biomedical devices where non-Newtonian and radiative influences are significant.
{"title":"Nonlinear analysis of thermo-magneto slip flow of Jeffery fluid in a wavy curved channel","authors":"Maham Mujahid , Mounirah Areshi , Zaheer Abbas , Muhammad Yousuf Rafiq , Ibrahim E. Elseesy","doi":"10.1016/j.dynatmoce.2025.101633","DOIUrl":"10.1016/j.dynatmoce.2025.101633","url":null,"abstract":"<div><div>This study conducts an analytical examination of thermo-magneto-hydrodynamic slip flow of a Jeffery fluid through a porous wavy curved channel. The energy equation incorporates the effects of thermal radiation along with heat generation and absorption mechanisms. By formulating the governing equations in curvilinear coordinates and applying a regular perturbation method, closed-form expressions for the velocity, temperature, skin-friction coefficient, and Nusselt number are obtained. The parametric investigation indicates that both channel curvature and porous permeability enhance fluid transport, while the applied magnetic field suppresses motion. Thermal radiation notably intensifies heat transfer and facilitates bolus formation by decreasing the effective viscosity and augmenting buoyancy effects. Overall, the findings provide a useful theoretical basis for the design and optimization of advanced thermal management systems, polymer processing technologies, and MHD-based biomedical devices where non-Newtonian and radiative influences are significant.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101633"},"PeriodicalIF":2.0,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.dynatmoce.2025.101632
B. Sheela Rani , D. Sathya Narayanan , M.B. Salma Jasmine , N.R. Krishnamoorthy , M. Roja Raman , Aneesh A. Lotliker , Abhisek Chatterjee
Anthropogenic activities had led to major climate changes, causing the oceans to warm rapidly. Subsequently, there is a need for accurate prediction of sea surface temperature (SST). The dynamic Indian Ocean climate, weather and marine ecology is significantly affected by SST changes. In this study, hourly and daily SST data, specifically from 15 and 7 RAMA stations (1 m deep) respectively, at different parts of Indian Ocean is utilized to forecast SST using four deep learning techniques; 1D Convolutional Neural Network (1D-CNN), Long Short-Term Memory (LSTM) network, 1DCNN-LSTM network and attention based 1DCNN-LSTM Architecture. The SST data obtained from RAMA buoy is trained using a sliding window method and model performance is evaluated based on evaluation matrices like Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and Mean Absolute error (MAE). The results indicated that 1DCNN-LSTM outperforms 1D-CNN and LSTM at most sites, consistently achieving lower MSE, RMSE and MAE. The findings also revealed that in places where SST shifts significantly, the new attention based 1DCNN-LSTM model often competes with or does better than all the other models in MAE. Distinctive physical phenomena like equatorial jets, thermohaline stratification, monsoon, Indian Ocean Bipolar (IOD) and El Niño-Southern Oscillation (ENSO) bring about geographical difference in performance. Hence, the study illustrates how deep learning frameworks make better SST predictions in complex ocean basins and thereby aids in anticipating climate change.
{"title":"Deep learning for sea surface temperature prediction in the Indian Ocean: A comparative study using 1D-CNN, LSTM, 1DCNN-LSTM and attention based 1DCNN-LSTM architectures","authors":"B. Sheela Rani , D. Sathya Narayanan , M.B. Salma Jasmine , N.R. Krishnamoorthy , M. Roja Raman , Aneesh A. Lotliker , Abhisek Chatterjee","doi":"10.1016/j.dynatmoce.2025.101632","DOIUrl":"10.1016/j.dynatmoce.2025.101632","url":null,"abstract":"<div><div>Anthropogenic activities had led to major climate changes, causing the oceans to warm rapidly. Subsequently, there is a need for accurate prediction of sea surface temperature (SST). The dynamic Indian Ocean climate, weather and marine ecology is significantly affected by SST changes. In this study, hourly and daily SST data, specifically from 15 and 7 RAMA stations (1 m deep) respectively, at different parts of Indian Ocean is utilized to forecast SST using four deep learning techniques; 1D Convolutional Neural Network (1D-CNN), Long Short-Term Memory (LSTM) network, 1DCNN-LSTM network and attention based 1DCNN-LSTM Architecture. The SST data obtained from RAMA buoy is trained using a sliding window method and model performance is evaluated based on evaluation matrices like Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and Mean Absolute error (MAE). The results indicated that 1DCNN-LSTM outperforms 1D-CNN and LSTM at most sites, consistently achieving lower MSE, RMSE and MAE. The findings also revealed that in places where SST shifts significantly, the new attention based 1DCNN-LSTM model often competes with or does better than all the other models in MAE. Distinctive physical phenomena like equatorial jets, thermohaline stratification, monsoon, Indian Ocean Bipolar (IOD) and El Niño-Southern Oscillation (ENSO) bring about geographical difference in performance. Hence, the study illustrates how deep learning frameworks make better SST predictions in complex ocean basins and thereby aids in anticipating climate change.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101632"},"PeriodicalIF":2.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.dynatmoce.2025.101629
Z. Abbas, S. Goher, M.Y. Rafiq
This study presents a comprehensive numerical investigation of two-phase boundary layer shear flows involving immiscible non-Newtonian Carreau and Tangent hyperbolic nanofluids incorporating motile microorganisms. The analysis explores the coupled effects of thermophoresis, Brownian motion, and thermal radiation on velocity, temperature, concentration, and microorganism density profiles across distinct shear regions. Incorporating microorganisms within nanofluids enhances thermal conductivity and stabilizes the flow structure, contributing to improved transport phenomena relevant to biomedical, energy, and environmental systems. The governing nonlinear differential equations are transformed into dimensionless form using similarity transformations and solved via the MATLAB bvp4c collocation method to ensure high numerical accuracy. A grid independence test confirms the convergence and stability of the scheme for all parametric variations. The results demonstrate that the Carreau fluid parameter promotes fluid velocity, while an increase in the viscosity ratio and shear strength ratio reduces it. Brownian motion and thermophoresis parameters suppress temperature near the interface, whereas thermal radiation enhances it. The density of motile microorganisms rises with higher bioconvection and Péclet numbers but decreases with increasing microorganism Schmidt number. Quantitative results for skin friction, Nusselt number, Sherwood number, and microorganism density validate the influence of these parameters in both regions. The findings provide valuable insights for optimizing microfluidic transport, bioconvective systems, and nanofluid-based heat exchangers where multi-phase shear interactions and microorganism activity are significant.
{"title":"Boundary layer interaction of immiscible non-Newtonian nanofluids in distinct shear flows with motile microorganisms","authors":"Z. Abbas, S. Goher, M.Y. Rafiq","doi":"10.1016/j.dynatmoce.2025.101629","DOIUrl":"10.1016/j.dynatmoce.2025.101629","url":null,"abstract":"<div><div>This study presents a comprehensive numerical investigation of two-phase boundary layer shear flows involving immiscible non-Newtonian Carreau and Tangent hyperbolic nanofluids incorporating motile microorganisms. The analysis explores the coupled effects of thermophoresis, Brownian motion, and thermal radiation on velocity, temperature, concentration, and microorganism density profiles across distinct shear regions. Incorporating microorganisms within nanofluids enhances thermal conductivity and stabilizes the flow structure, contributing to improved transport phenomena relevant to biomedical, energy, and environmental systems. The governing nonlinear differential equations are transformed into dimensionless form using similarity transformations and solved via the MATLAB bvp4c collocation method to ensure high numerical accuracy. A grid independence test confirms the convergence and stability of the scheme for all parametric variations. The results demonstrate that the Carreau fluid parameter promotes fluid velocity, while an increase in the viscosity ratio and shear strength ratio reduces it. Brownian motion and thermophoresis parameters suppress temperature near the interface, whereas thermal radiation enhances it. The density of motile microorganisms rises with higher bioconvection and Péclet numbers but decreases with increasing microorganism Schmidt number. Quantitative results for skin friction, Nusselt number, Sherwood number, and microorganism density validate the influence of these parameters in both regions. The findings provide valuable insights for optimizing microfluidic transport, bioconvective systems, and nanofluid-based heat exchangers where multi-phase shear interactions and microorganism activity are significant.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101629"},"PeriodicalIF":2.0,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.dynatmoce.2025.101616
S.M. Sachhin , M.S. Bharath , G.M. Sachin , U.S. Mahabaleshwar , D. Laroze , H.F. Oztop
The current research aims to examine the Joule heating and magnetic field influence on micropolar fluid flow across expanding surface, which is is significant in enhancing the efficiency in biomedical and engineering fields, In this analysis, examined the influence of entropy generation, magnetic field, porous medium, and prescribed boundary restrictions. To the best of authors knowledge, no prior research has studied all these effects simultaneously, which emphasizes the originality of the current analysis. The considered governing partial differential equations are transformed to ordinary differential equations by using similarity expressions and then formulated analytically using hypergeometric series solutions. The dual solutions have been extracted from the current analysis which offers deeper insights into the micropolar fluid behaviour under considered physical effects. The outcomes of the present analysis reveal that enhancing the porous media and magnetic field reduces the momentum by 15 %. With enhancing the internal heat source enhances the temperature by 20 %, and thermal radiation enhances temperature by 29 %, enhancing the viscosity ration reduces the velocity by 23 %. These results help in analysing the blood movement modelling, advanced medical therapies, and magnetic drug delivery among others.
{"title":"Multiple analytic solutions for irreversible mechanism and Joule heating impact on dissipative micropolar fluid flow driven by stretching/shrinking surface with PST and PHF boundary conditions","authors":"S.M. Sachhin , M.S. Bharath , G.M. Sachin , U.S. Mahabaleshwar , D. Laroze , H.F. Oztop","doi":"10.1016/j.dynatmoce.2025.101616","DOIUrl":"10.1016/j.dynatmoce.2025.101616","url":null,"abstract":"<div><div>The current research aims to examine the Joule heating and magnetic field influence on micropolar fluid flow across expanding surface, which is is significant in enhancing the efficiency in biomedical and engineering fields, In this analysis, examined the influence of entropy generation, magnetic field, porous medium, and prescribed boundary restrictions. To the best of authors knowledge, no prior research has studied all these effects simultaneously, which emphasizes the originality of the current analysis. The considered governing partial differential equations are transformed to ordinary differential equations by using similarity expressions and then formulated analytically using hypergeometric series solutions. The dual solutions have been extracted from the current analysis which offers deeper insights into the micropolar fluid behaviour under considered physical effects. The outcomes of the present analysis reveal that enhancing the porous media and magnetic field reduces the momentum by 15 %. With enhancing the internal heat source enhances the temperature by 20 %, and thermal radiation enhances temperature by 29 %, enhancing the viscosity ration reduces the velocity by 23 %. These results help in analysing the blood movement modelling, advanced medical therapies, and magnetic drug delivery among others.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"112 ","pages":"Article 101616"},"PeriodicalIF":2.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 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 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 () and unary nanofluid (), 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.
{"title":"Energy transport in ternary hybrid nanofluid with variable thermal conductivity under the combined effects of electroviscous, electric potential, and heat generation","authors":"Shafiq Ahmad , Aamir Abbas Khan , Muhammad Naveed Khan , Salah Knani , N. Ameer Ahammad , Ibrahim E. Elseesy","doi":"10.1016/j.dynatmoce.2025.101619","DOIUrl":"10.1016/j.dynatmoce.2025.101619","url":null,"abstract":"<div><div>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 <span><math><mrow><mi>M</mi><mi>W</mi><mi>C</mi><mi>N</mi><mi>T</mi><mo>+</mo><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>+</mo><mi>S</mi><mi>i</mi><mi>C</mi><mo>/</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>O</mi></mrow></math></span> 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 (<span><math><mrow><mi>M</mi><mi>W</mi><mi>C</mi><mi>N</mi><mi>T</mi><mo>+</mo><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>+</mo><mi>S</mi><mi>i</mi><mi>C</mi><mo>/</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>O</mi></mrow></math></span>) and unary nanofluid (<span><math><mrow><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>/</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>O</mi></mrow></math></span>), 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.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"112 ","pages":"Article 101619"},"PeriodicalIF":2.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.dynatmoce.2025.101621
Yazeed Alsubhi , Bassam M. Aljahdali , Ayman F. Alghanmi , Hussain T. Sulaimani , Ahmad E. Samman
Dust storms represent a significant hazard to maritime navigation, particularly in regions such as Saudi Arabia, where frequent dust events, driven by vast desert landscapes and oceanic wind patterns, reduce visibility and disrupt maritime operations. This paper proposes a comprehensive framework for evaluating visibility risks posed by dust storms in Saudi Arabian maritime zones, specifically focusing on the Red Sea. The methodology considers MODIS AOD (Aerosol Optical Depth) data, wind speed, and cloud cover to develop a dynamic risk assessment model using random forest (RF) for dust storm detection and visibility risk prediction. The model integrates spatial data layers for environmental factors (wind, waves, and depth), creating seasonal risk maps that dynamically adjust based on changing environmental conditions. GIS technology was used to visualize risk zones, and the RF model provided data-driven weighting of risk factors. The model’s performance was validated using metrics such as probability of detection (POD) (0.92), probability of false detection (PFD) (0.05), and equitable threat score (ETS) (0.85), demonstrating superior accuracy over traditional methods like analytic hierarchy process (AHP) and CRiteria importance through intercriteria correlation (CRITIC). The findings indicate that Autumn represents the most hazardous season for maritime navigation due to frequent dust storms, with the central Red Sea being the most impacted area. The results demonstrate the potential of this approach for improving navigation safety and early warning tools in the Red Sea and similar arid coastal regions.
{"title":"Risk mapping of dynamic dust storms and multi-hazard maritime navigation in the red sea using machine learning and MODIS Data","authors":"Yazeed Alsubhi , Bassam M. Aljahdali , Ayman F. Alghanmi , Hussain T. Sulaimani , Ahmad E. Samman","doi":"10.1016/j.dynatmoce.2025.101621","DOIUrl":"10.1016/j.dynatmoce.2025.101621","url":null,"abstract":"<div><div>Dust storms represent a significant hazard to maritime navigation, particularly in regions such as Saudi Arabia, where frequent dust events, driven by vast desert landscapes and oceanic wind patterns, reduce visibility and disrupt maritime operations. This paper proposes a comprehensive framework for evaluating visibility risks posed by dust storms in Saudi Arabian maritime zones, specifically focusing on the Red Sea. The methodology considers MODIS AOD (Aerosol Optical Depth) data, wind speed, and cloud cover to develop a dynamic risk assessment model using random forest (RF) for dust storm detection and visibility risk prediction. The model integrates spatial data layers for environmental factors (wind, waves, and depth), creating seasonal risk maps that dynamically adjust based on changing environmental conditions. GIS technology was used to visualize risk zones, and the RF model provided data-driven weighting of risk factors. The model’s performance was validated using metrics such as probability of detection (POD) (0.92), probability of false detection (PFD) (0.05), and equitable threat score (ETS) (0.85), demonstrating superior accuracy over traditional methods like analytic hierarchy process (AHP) and CRiteria importance through intercriteria correlation (CRITIC). The findings indicate that Autumn represents the most hazardous season for maritime navigation due to frequent dust storms, with the central Red Sea being the most impacted area. The results demonstrate the potential of this approach for improving navigation safety and early warning tools in the Red Sea and similar arid coastal regions.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101621"},"PeriodicalIF":2.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1016/j.dynatmoce.2025.101620
P.P. Nayak , S.R. Mishra , Subhajit Panda
Viscoelastic fluids change their rheological properties in response to an applied electric or magnetic field. In particular, applications in vehicle damping systems, vibration control devices, shock absorbers, and smart materials for structural engineering the role of viscoelastic fluid is vital. Therefore, the proposed study investigates the influence of magnetized viscoelastic fluid through a permeable medium due to the interaction of a heat source/sink. The free convection with radiative heat transfer characterizes the transport properties significantly. The relevant similarity rules are adopted for the transmutation of the governing phenomena into ordinary as well as dimensionless. Further, the complexity of the flow phenomena impulses to the implementation of perturbation technique to reduce the order of the problem, and then a numerical method such as shooting combined with Runge-Kutta fourth-order contributes to solving the system. Graphs are used to illustrate the characteristics of physical parameters that contribute to the flow phenomena. However, the analysis ended with important flow behaviour described briefly in the conclusion. The study reveals that the heat transfer shows dual behavior with magnetic and radiation effects, being stronger in permeable media. Magnetization reduces shear and mass transfer, while buoyancy boosts velocity. Radiation and chemical reactions influence temperature rise and concentration drop, respectively.
{"title":"Behavior of magneto-viscoelastic fluid flow through a permeable medium with heat source/sink using hybrid methodology","authors":"P.P. Nayak , S.R. Mishra , Subhajit Panda","doi":"10.1016/j.dynatmoce.2025.101620","DOIUrl":"10.1016/j.dynatmoce.2025.101620","url":null,"abstract":"<div><div>Viscoelastic fluids change their rheological properties in response to an applied electric or magnetic field. In particular, applications in vehicle damping systems, vibration control devices, shock absorbers, and smart materials for structural engineering the role of viscoelastic fluid is vital. Therefore, the proposed study investigates the influence of magnetized viscoelastic fluid through a permeable medium due to the interaction of a heat source/sink. The free convection with radiative heat transfer characterizes the transport properties significantly. The relevant similarity rules are adopted for the transmutation of the governing phenomena into ordinary as well as dimensionless. Further, the complexity of the flow phenomena impulses to the implementation of perturbation technique to reduce the order of the problem, and then a numerical method such as shooting combined with Runge-Kutta fourth-order contributes to solving the system. Graphs are used to illustrate the characteristics of physical parameters that contribute to the flow phenomena. However, the analysis ended with important flow behaviour described briefly in the conclusion. The study reveals that the heat transfer shows dual behavior with magnetic and radiation effects, being stronger in permeable media. Magnetization reduces shear and mass transfer, while buoyancy boosts velocity. Radiation and chemical reactions influence temperature rise and concentration drop, respectively.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101620"},"PeriodicalIF":2.0,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145625414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.dynatmoce.2025.101618
Xiaoxuan Su , Yihe Fang , Ling Zhu , Chenghan Liu , Zhenghua Tan
Based on daily precipitation data from 87 national rain gauge stations in Northeast China from 1981 to 2023 and the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data, This study reveals the characteristics of low-frequency activities of Northeast China cold vortex (NCCV) during the warm season and their impact on precipitation in Northeast China. The results show that the low-frequency activities of NCCV are closely related to the intraseasonal oscillation of middle-high latitudes. When the low-frequency NCCV activities reach the strongest, the geopotential height field over Northeast China exhibits negative anomalies, and the high-latitudes of the Eurasian continent show an anomaly pattern of “− + −”. When the NCCV key area is controlled by high-pressure anomalies, the middle-high latitudes are dominated by the East Asian-Pacific pattern from May to June. From July to September, the East Asian-Pacific pattern is weak and the Eurasian pattern is dominant. During the active phase of NCCV, Northeast China is under the control of a strong westerly jet, which is conducive to upper-level divergence. This further promotes the maintenance and development of cold vortices. At this time, the NCCV is located between two jets, which benefits energy accumulation and moisture transport. Moreover, there is obvious ascending motion over Northeast China, providing favorable dynamic conditions for notable low-frequency precipitation. The upper level low-frequency vorticity can also reflect the propagation of low frequency oscillations in the NCCV key area, as well as its upstream and downstream regions. When the NCCV is the strongest, the rear of the key area is controlled by positive vorticity anomalies, while the front is controlled by negative vorticity anomalies. The phases of NCCV low-frequency activities have good indications for cold vortex precipitation in early summer and midsummer in Northeast China. From phases 1–4, the low-frequency precipitation in Northeast China is less. As the low-frequency NCCV forms, develops and moves eastward (phases 5–8), the low-frequency rain band generates in the Liaoning Province and gradually moves northeastward, affecting Jilin and Heilongjiang provinces. As the low-frequency NCCV weakens and moves out, the precipitation in Northeast China gradually decreases from southwest to northeast.
{"title":"Characteristics of low-frequency activities of Northeast China cold vortices and their impacts on the precipitation in Northeast China","authors":"Xiaoxuan Su , Yihe Fang , Ling Zhu , Chenghan Liu , Zhenghua Tan","doi":"10.1016/j.dynatmoce.2025.101618","DOIUrl":"10.1016/j.dynatmoce.2025.101618","url":null,"abstract":"<div><div>Based on daily precipitation data from 87 national rain gauge stations in Northeast China from 1981 to 2023 and the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data, This study reveals the characteristics of low-frequency activities of Northeast China cold vortex (NCCV) during the warm season and their impact on precipitation in Northeast China. The results show that the low-frequency activities of NCCV are closely related to the intraseasonal oscillation of middle-high latitudes. When the low-frequency NCCV activities reach the strongest, the geopotential height field over Northeast China exhibits negative anomalies, and the high-latitudes of the Eurasian continent show an anomaly pattern of “− + −”. When the NCCV key area is controlled by high-pressure anomalies, the middle-high latitudes are dominated by the East Asian-Pacific pattern from May to June. From July to September, the East Asian-Pacific pattern is weak and the Eurasian pattern is dominant. During the active phase of NCCV, Northeast China is under the control of a strong westerly jet, which is conducive to upper-level divergence. This further promotes the maintenance and development of cold vortices. At this time, the NCCV is located between two jets, which benefits energy accumulation and moisture transport. Moreover, there is obvious ascending motion over Northeast China, providing favorable dynamic conditions for notable low-frequency precipitation. The upper level low-frequency vorticity can also reflect the propagation of low frequency oscillations in the NCCV key area, as well as its upstream and downstream regions. When the NCCV is the strongest, the rear of the key area is controlled by positive vorticity anomalies, while the front is controlled by negative vorticity anomalies. The phases of NCCV low-frequency activities have good indications for cold vortex precipitation in early summer and midsummer in Northeast China. From phases 1–4, the low-frequency precipitation in Northeast China is less. As the low-frequency NCCV forms, develops and moves eastward (phases 5–8), the low-frequency rain band generates in the Liaoning Province and gradually moves northeastward, affecting Jilin and Heilongjiang provinces. As the low-frequency NCCV weakens and moves out, the precipitation in Northeast China gradually decreases from southwest to northeast.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101618"},"PeriodicalIF":2.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work concisely investigates unsteady magnetohydrodynamic (MHD) convection of nanofluids within a confined enclosure subjected to an inclined magnetic field and internal heat generation or absorption. Utilizing the Buongiorno model, which incorporates thermophoresis and Brownian motion, the coupled mass, momentum, energy, and nanoparticle concentration equations are solved using the finite element method (FEM), which is an efficient procedure for solving two-dimensional thermal problems. Parametric analysis is carried out over Reynolds, Hartmann, and Schmidt numbers, magnetic field inclination angle, and heat source/sink strength. Results indicate that higher Reynolds numbers significantly enhance fluid flow and the mean Nusselt number. Increasing Hartmann numbers suppresses convection but yields modest improvements in heat transfer. A magnetic inclination of 30° maximizes heat transfer efficiency. Elevated Schmidt numbers enhance momentum transport but decrease thermal efficiency due to reduced mass diffusivity. Internal heat generation significantly enhances heat transfer performance, resulting in nearly a 300 % increase in Nusselt numbers at the base wall under conditions of heat generation. These findings offer valuable insights into the dynamic coupling of nanoparticle transport, magnetic control, and thermal regulation in unsteady MHD systems.
{"title":"Thermomagnetic unsteady convection of nanofluid flow in an inclined-field cavity","authors":"Majdeddin Emad , Payam Jalili , Bahram Jalili , Davood Domiri Ganji","doi":"10.1016/j.dynatmoce.2025.101617","DOIUrl":"10.1016/j.dynatmoce.2025.101617","url":null,"abstract":"<div><div>This work concisely investigates unsteady magnetohydrodynamic (MHD) convection of nanofluids within a confined enclosure subjected to an inclined magnetic field and internal heat generation or absorption. Utilizing the Buongiorno model, which incorporates thermophoresis and Brownian motion, the coupled mass, momentum, energy, and nanoparticle concentration equations are solved using the finite element method (FEM), which is an efficient procedure for solving two-dimensional thermal problems. Parametric analysis is carried out over Reynolds, Hartmann, and Schmidt numbers, magnetic field inclination angle, and heat source/sink strength. Results indicate that higher Reynolds numbers significantly enhance fluid flow and the mean Nusselt number. Increasing Hartmann numbers suppresses convection but yields modest improvements in heat transfer. A magnetic inclination of 30° maximizes heat transfer efficiency. Elevated Schmidt numbers enhance momentum transport but decrease thermal efficiency due to reduced mass diffusivity. Internal heat generation significantly enhances heat transfer performance, resulting in nearly a 300 % increase in Nusselt numbers at the base wall under conditions of heat generation. These findings offer valuable insights into the dynamic coupling of nanoparticle transport, magnetic control, and thermal regulation in unsteady MHD systems.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101617"},"PeriodicalIF":2.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 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.
{"title":"Non-Darcy and Joule heating in MHD convective micropolar heat transfer flow over a stretchy cooling sheet with variable heat gain","authors":"T. Venu , MD. Shamshuddin , S.O. Salawu , Subhajit Panda","doi":"10.1016/j.dynatmoce.2025.101615","DOIUrl":"10.1016/j.dynatmoce.2025.101615","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"112 ","pages":"Article 101615"},"PeriodicalIF":2.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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