Dynamics of Atmospheres and Oceans最新文献

{"title":"Dynamic and thermodynamic characteristics of the Bay of Bengal cyclones during 2001–20 and impact of scatterometer winds through composite analysis","authors":"Ipshita Bhasi ,&nbsp;Jagabandhu Panda ,&nbsp;Subodh Kumar ,&nbsp;Debashis Paul ,&nbsp;Ashish Routray","doi":"10.1016/j.dynatmoce.2025.101564","DOIUrl":"10.1016/j.dynatmoce.2025.101564","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"111 ","pages":"Article 101564"},"PeriodicalIF":1.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241083","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}

{"title":"Evaluating weather trends and forecasting with machine learning: Insights from maximum temperature, minimum temperature, and rainfall data in India","authors":"Guhan V ,&nbsp;A. Dharma Raju ,&nbsp;Rama Krishna ,&nbsp;K. Nagaratna","doi":"10.1016/j.dynatmoce.2025.101562","DOIUrl":"10.1016/j.dynatmoce.2025.101562","url":null,"abstract":"<div><div>This research presents a comprehensive evaluation of meteorological trends using a combination of statistical and machine learning approaches, focusing on rainfall, minimum temperature (MinT), and maximum temperature (MaxT). The Mann-Kendall trend test and Sen’s slope estimator identified statistically significant upward trends in both MaxT (slope = 0.0154, p = 9.42E-06) and MinT (slope = 0.0190, p = 4.73E-07), indicating a consistent warming climate. Rainfall displayed a positive trend but was not statistically significant (p = 0.9516, slope = 4.07E-05), suggesting random variability rather than a sustained increase.Machine learning models were leveraged to enhance forecasting accuracy for these meteorological parameters. ARIMA exhibited the highest precision for MaxT and Rainfall (MAE = 3.0080, 0.1728; RMSE = 3.4967, 0.2916), while XGBoost demonstrated superior performance for MinT (MAE = 2.7726, RMSE = 3.8555). These findings highlight the critical need for climate adaptation measures, as rising temperatures could intensify heatwaves, escalate energy demands, and affect agricultural productivity.The study underscores the importance of integrating advanced forecasting techniques to support proactive climate resilience planning. By incorporating machine learning models with traditional statistical analyses, this research provides valuable insights into climate trends, aiding policymakers and researchers in formulating effective climate adaptation strategies.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101562"},"PeriodicalIF":1.9,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144146714","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}

{"title":"How does HAIKUI remnant produce heavy precipitation in 2023","authors":"Ping Ye ,&nbsp;Yuan Zhu ,&nbsp;Haoya Liu","doi":"10.1016/j.dynatmoce.2025.101563","DOIUrl":"10.1016/j.dynatmoce.2025.101563","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"111 ","pages":"Article 101563"},"PeriodicalIF":1.9,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314167","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}

{"title":"New formulas for estimating initial dilution of buoyancy-dominated jets in a current","authors":"Galip Seckin ,&nbsp;Cagatayhan Bekir Ersu ,&nbsp;Irfan Macit","doi":"10.1016/j.dynatmoce.2025.101561","DOIUrl":"10.1016/j.dynatmoce.2025.101561","url":null,"abstract":"<div><div>For buoyancy-dominated effluents discharged into moving water, three distinct regions are recognized: the buoyancy-dominated near field (BDNF), the buoyancy-dominated far field (BDFF), and an intermediate transition region. Most existing initial dilution formulas—derived from empirical and field studies—focus on the BDNF and BDFF regions while neglecting the transition zone. In this study, two new semi-empirical equations were developed using field and experimental data: one for submerged discharges and another for minimum surface dilution. These equations were calibrated via nonlinear regression, offering a unified approach to effectively calculating initial dilution across both the BDNF and BDFF regions while also addressing the transition region’s dilution in a single step. The proposed formulas were further validated through comparison with an earlier semi-empirical model using the same dataset.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101561"},"PeriodicalIF":1.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144146715","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}

{"title":"The effects of climate change on the thermal stratification of the Gulf of Oman","authors":"Shirin Farkhani,&nbsp;Nasser Hadjizadeh Zaker","doi":"10.1016/j.dynatmoce.2025.101560","DOIUrl":"10.1016/j.dynatmoce.2025.101560","url":null,"abstract":"<div><div>Water temperature and thermal stratification have fundamental effects on marine environments, ecosystems, and water circulation patterns. Marine ecosystems are generally highly sensitive to thermal changes. Global warming can fundamentally alter oceanic temperature fields and thermal stratification(Cheng, 2019)(Cheng, 2019). Therefore, studying the effects of climate change on the thermal characteristics of the oceans and seas is vital. Using numerical modeling, and three Representative Concentration Pathway (RCP) scenarios, we studied the effects of global warming on the sea surface temperature and vertical thermal structure of the Gulf of Oman. Atmospheric data from the ERA5 and CORDEX models were used for recent past (1980–2000) and future (2080–2100) modeling, respectively. Results indicated that, in the future climate, the temperature across the upper 1000 m of the Gulf of Oman will increase. In summer, temperature increments in the surface mixed layer were estimated at + 1.9, + 2.5, and + 3.4°C for RCP 2.6, 4.5, and 8.5, respectively. Below the thermocline, the temperature increments were less than the ones in the surface mixed layer. In winter, future temperature increments in the surface mixed layer were + 1.2, + 1.6, and + 2°C for RCP 2.6, 4.5, and 8.5, respectively. The results indicated a stronger summer thermocline in the future with temperature gradients of 0.055, 0.057, and 0.06 °C/m in the RCP 2.6, 4.5, and 8.5, respectively, which could significantly reduce dissolved oxygen concentration in the lower layers. This study provides insights that can help develop adaptable strategies to manage and mitigate the harmful impacts of global warming on the Gulf of Oman.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101560"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948917","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}

{"title":"Improving significant wave height prediction via temporal data imputation","authors":"Jia Si ,&nbsp;Jie Wang ,&nbsp;Yingjun Deng","doi":"10.1016/j.dynatmoce.2025.101549","DOIUrl":"10.1016/j.dynatmoce.2025.101549","url":null,"abstract":"<div><div>Accurate prediction of significant wave height (SWH) is crucial for a wide range of marine and coastal applications. However, achieving an accurate data-driven prediction of SWH requires effective multivariate time series modeling. Furthermore, missing values appear frequently in the raw data and influence the accuracy of the prediction. In this study, we propose a novel diffusion-based approach for continuous-time modeling and temporal imputation of multivariate time series. By learning the temporal correlations and interdependencies among variables in the buoy’s data, the imputation of missing data is conducted to enhance the SWH prediction. Experiments are performed using buoy data from the National Data Buoy Center of USA to validate the effectiveness of temporal imputation and the use of multivariate data. The experimental results, compared with baseline methods and univariate predictions, highlight the advantage of Conditional Score-Based Diffusion Models (CSDI) in capturing temporal correlations and its effectiveness in improving short-term predictions of SWH. CSDI improves imputation by 7%–30% over existing imputation methods on popular performance metrics. Compared to univariate data, the better SWH prediction results on multivariate data confirm that temporal data imputation is beneficial for prediction.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101549"},"PeriodicalIF":1.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089266","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}

{"title":"Formation mechanism of overshooting convection in the southwest vortex circulation under the influence of mesoscale gravity wave","authors":"Yizhou Xu ,&nbsp;Guoping Li ,&nbsp;Xiaoyu Zhang ,&nbsp;Yuanchang Dong ,&nbsp;Xin Xie","doi":"10.1016/j.dynatmoce.2025.101559","DOIUrl":"10.1016/j.dynatmoce.2025.101559","url":null,"abstract":"<div><div>Using ERA5 reanalysis data, GPM satellite precipitation products, and radar mosaic combination reflectivity (RMCR) data, the formation mechanism of overshooting convection (OC) in the southwest vortex (SWV) circulation under the influence of mesoscale gravity wave (MGW) on 18 Jul 2022 was analyzed on synoptic dynamics to deepen the understanding of the correlation characteristics between the SWV and the MGW, and then to explore the formation mechanism of OC in the Sichuan Basin (SCB). Results showed that the undulating terrain and stable atmospheric stratification generated the MGW. The adjustment of the SWV circulation caused the strong water vapor flux convergence at 850 hPa in the early stage of OC. The change of divergence field caused by MGW promoted the eastward development of the updraft in the SWV circulation, and the SWV center tilted to the southeast. The ascending center separated by the SWV merged horizontally with the updraft phase of MGW, and the merged ascending airflow connected vertically to the ascending center in the upper troposphere. The water vapor convergence and heating center in the upper troposphere and the horizontal wind momentum transporting upward led to OC. The strengthening of the negative vertical vorticity phase of MGW and the movement of dry cold air mass led to the northwestward propagation of negative vertical vorticity, thus forming the difference in the vertical distribution of vertical vorticity, which was negative in the upper and positive in the lower. The stable updraft phase of the MGW and the dry cold air mass propagation cooled the lower atmosphere and increased the convective available potential energy (CAPE). The adjustment of the internal circulation of the SWV extended the range of convective instability from the ground to 600 hPa, which was also conducive to the formation of OC.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101559"},"PeriodicalIF":1.9,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068184","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}

{"title":"The Caspian Sea as a full-scale experimental facility supported by altimetry measurements of wind-driven waves","authors":"Sergei I. Badulin ,&nbsp;Andrey G. Kostianoy ,&nbsp;Sergey A. Lebedev ,&nbsp;Alexander P. Popov","doi":"10.1016/j.dynatmoce.2025.101554","DOIUrl":"10.1016/j.dynatmoce.2025.101554","url":null,"abstract":"<div><div>The Caspian Sea is the largest inland water body. Strong and stable winds regularly occur along its longest stretch of more than 1000 km from the Volga Lowland in Russia to the Iranian coast. During these events, wind speeds can exceed 20 m/s and significant wave heights 5 m. These wind directions often align with the tracks of satellite altimeters that have been monitoring the sea state since September 1992. This makes the Caspian Sea an ideal location replicating idealized conditions for the growth of wind-driven waves, and supported by a high-precision network of satellite altimeters.</div><div>The shape of the coastline and prevalent wind directions allowed us to view the sea as a full-scale wind-wave research facility. In situ measurements and observations of sea state in this area are scarce and inaccurate while the altimetry tracks provide a ready-to-use high-quality measurement network. We analyze data of satellite missions Jason-3 for years 2016-2022 and CFOSAT (Chinese-French Oceanography SATellite) for 2019-2023 to assess the potential of the full-scale experimental facility. These missions provide valuable data showcasing the Caspian Sea as a realistic model for the World Ocean with minimal contaminating effects of swell, tides and currents. This makes the “clean cases” of the Caspian Sea particularly valuable both as a reference for understanding general wave physics and for regional studies on sea wave dynamics.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101554"},"PeriodicalIF":1.9,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936014","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}

{"title":"Monsoon dynamics and future projections in the Himalaya: Insights into sea surface temperature, sea level pressure relationships, and future flood risks","authors":"Mayank Shekhar ,&nbsp;Pushpendra Pandey ,&nbsp;Shaktiman Singh ,&nbsp;Anupam Sharma","doi":"10.1016/j.dynatmoce.2025.101558","DOIUrl":"10.1016/j.dynatmoce.2025.101558","url":null,"abstract":"<div><div>The Himalaya influences the fundamental features of the Indian Summer Monsoon (ISM) circulation across South Asia. Reliable predictions of ISM dynamics require an improved understanding of the relationship with the El Niño–Southern Oscillation (ENSO)–sea surface temperature (SST) and Sea Level Pressure (SLP) relationships in the Niño region. To address this, we conducted a detailed analysis of teleconnections, correlations, regime shifts, periodicity, and return periods of monsoons over the Karakoram Himalaya (KH), Western Himalaya (WH), Central Himalaya (CH), and Eastern Himalaya (EH) using gridded precipitation, ENSO-SST, and SLP data across the Niño 4, 3.4, and 3 regions. Additionally, we examined Coupled Model Intercomparison Project phase 5 (CMIP5) projections considering evolving relationships. The findings show that the monsoons over the CH, WH, EH, and KH have stronger, moderate, weaker, and weakest spatial correlations, respectively, with the SST of Niño regions. Notably, the SST anomalies for the Niño regions 4 and 3.4 reveal distinct regime shift for the years 1977 C.E. and 1990 C.E., however, Niño regions 3 and 1 + 2, do not exhibit any such shift. The SST anomalies for the Niño 3.4 and Niño 4 from 1977 to 2019 C.E., and 1990–2019 C.E., were 0.087°C and 0.060°C, respectively, indicating systematic warming of the sea surface. This warming trend is further linked to projections from CMIP5 RCP 4.5 and RCP 8.5, which suggest that the EH region may experience significant flooding during the monsoon months by 2100 due to high and extreme precipitation.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101558"},"PeriodicalIF":1.9,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948916","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}

{"title":"Comparative drought analysis in Amasya and Merzifon with ZSI, PNI and NDI under transitional climatic conditions","authors":"Utku Zeybekoglu","doi":"10.1016/j.dynatmoce.2025.101556","DOIUrl":"10.1016/j.dynatmoce.2025.101556","url":null,"abstract":"<div><div>Drought is a recurring global problem characterised by multiple climatological and hydrological parameters, causing significant damage to both the natural environment and life. The onset of a drought is characterised by a meteorological drought, which is defined as a decrease in precipitation. The present study investigates the meteorological drought experienced by Amasya and Merzifon, which are located within the transition zone between the Black Sea and continental climates in Türkiye. The drought analysis utilised the ZSI, the PNI and the NDI which is a metric employed to quantify drought. Furthermore, the temporal trends of precipitation, temperature and drought values were investigated using Mann-Kendall, Spearman's Rho and Innovative Trend Analysis. The Drought Indices (DIs) identified significant dry years in 1964–1966, 1974–1975, 1981–1982, 1984, 1986, 1989–1990, 1994, 1999, 2001–2003, 2006–2007, 2011, 2013–2015, and 2017–2021. The assessment revealed that the ZSI, the PNI and NDI performed similarly in terms of identifying drought. The trend analysis results indicate a rising trend in precipitation and temperatures. While ZSI and PNI show an increasing trend, NDI also tends to decrease due to the effect of temperature. The results of both the drought and trend analyses suggest that temperature plays a more influential role in the regional climate compared to other meteorological parameters.The findings reveal the historical development of droughts in the region and their effects on the region's environment with different drought indices. The findings herein have the potential to provide a scientific foundation for the management of local drought conditions. It is posited that by implementing preventative measures and formulating suitable strategies, the likelihood of significant drought-related problems can be substantially mitigated.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"110 ","pages":"Article 101556"},"PeriodicalIF":1.9,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886841","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}