Dynamics of Atmospheres and Oceans最新文献

筛选
英文 中文
Nonlinear flow of couple stress fluid layer over an inclined plate 倾斜板上耦合应力流体层的非线性流动
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-29 DOI: 10.1016/j.dynatmoce.2023.101428
Magdy A. Sirwah , Ahmed Assaf
{"title":"Nonlinear flow of couple stress fluid layer over an inclined plate","authors":"Magdy A. Sirwah ,&nbsp;Ahmed Assaf","doi":"10.1016/j.dynatmoce.2023.101428","DOIUrl":"10.1016/j.dynatmoce.2023.101428","url":null,"abstract":"<div><p>The issue of stability of a thin couple-stress liquid layer flows on an inclined plane was inspected. The thin-film approximation was employed to obtain a Benney-like differential equation, that described the time record of the interface profile The linear transition state and reduction ratio of maximum classical (Newtonian) growth-rate were discussed. The complete evolution equation was solved numerically using the method of lines in order to support the novelty of the work. The linear stability could be enhanced by increasing the couple-stress coefficient and surface tension as well as reducing the inclination. However, the ordinary viscosity played an irregular role. The linear results predicted conditions (windows) in which the non-Newtonian film was more stable than its Newtonian counterpart. The nonlinear stimulation anticipated the existence of sock waves in certain situations. The appearance of instability through the linear subcritical region as well as irregular influences with respect to surface tension and couple-stress property was revealed. The nonlinear approach was more accurate in describing the stability issue than the linear one. Such results could be employed to attain the optimum statuses with regard to the film stability, and control the shock waves. They would not only enable accurate practical implementation in the design of inertial confinement fusion<span> capsules and supernova explosions and implosions modeling, but also would allow for precise numerical simulation.</span></p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101428"},"PeriodicalIF":1.7,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139070754","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}
引用次数: 0
The strengthened role of new predictors of Indian Ocean Dipole (IOD) during the recent decades of weakened ENSO-IOD relationship 在厄尔尼诺/南方涛动-印度洋偶极子(IOD)关系减弱的最近几十年里,印度洋偶极子(IOD)新预测因子的作用得到加强
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-28 DOI: 10.1016/j.dynatmoce.2023.101432
Prasanth A. Pillai , V.G. Kiran , K.V. Suneeth
{"title":"The strengthened role of new predictors of Indian Ocean Dipole (IOD) during the recent decades of weakened ENSO-IOD relationship","authors":"Prasanth A. Pillai ,&nbsp;V.G. Kiran ,&nbsp;K.V. Suneeth","doi":"10.1016/j.dynatmoce.2023.101432","DOIUrl":"10.1016/j.dynatmoce.2023.101432","url":null,"abstract":"<div><p><span><span>Indian Ocean Dipole (IOD) is the major interannual ocean-atmosphere interaction phenomena in the Indian Ocean (IO) and is influenced by external forcing such as </span>El Nino Southern Oscillation (ENSO). Meanwhile, its co-occurrence and stronger relationship with ENSO have decreased during recent decades. The IOD variability also reduced after 2000, accompanied by a shift of the western pole to central IO extending further southward. The study reports that the boreal fall </span><strong>(</strong>SON, September, October, November<strong>)</strong><span><span> season IOD has an intensified relationship with the previous winter Subtropical Indian Ocean dipole (SIOD) and spring season equatorial north tropical Atlantic (NTA) </span>SST<span> anomalies., while the ENSO relationship is reduced from its pre-2000 value. It is found that the persistent warming (cooling) in the western side of positive (negative) SIOD during the previous winter induces easterly (westerly) wind anomalies in the equatorial IO during the following summer and fall, leading to positive (negative) IOD events. These IOD events have the western pole shifted to south-central IO instead of the canonical northwestern warming. The spring season NTA SST anomalies induce stronger summer season circulation and SST gradient in the equatorial Pacific, like ENSO. During the SON season, this pattern is associated with cooling and easterly wind anomalies in the tropical eastern IO and IOD. These two patterns explain the major mode of IOD variability after 2000. While the IOD associated with NTA have co-occurring ENSO during summer and fall, the SIOD-induced IOD events are independent of ENSO in the Pacific. Thus, these two predictors provide long-lead predictability (2–3 seasons ahead) of IOD for both ENSO co-occurring and non-ENSO IOD events. However, the IOD predictability of seasonal prediction models mainly depends on the ENSO-IOD relationship, resulting in reduced IOD skills for many of them after 2000. The models such as COLA-CCSM4, which has improved skill have stronger than observed ENSO-IOD relationship than the pre-2000 period. A linear regression model including SIOD and NTA SST indices of the previous winter and spring season respectively as predictors simulates IOD with a skill of around 0.65 during the recent period, indicating the necessity of seasonal prediction models to capture the variability in the southern IO and NTA and their teleconnections for better prediction of IOD in the recent period of reduced ENSO skill.</span></span></p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101432"},"PeriodicalIF":1.7,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139070535","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}
引用次数: 0
The extraordinary atmospheric rivers analysis over the Middle East: Large-scale drivers, structure, effective sources, and precipitation characterization 中东地区上空非同寻常的大气河流分析:大尺度驱动因素、结构、有效来源和降水特征描述
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-23 DOI: 10.1016/j.dynatmoce.2023.101430
Neda Esfandiari , Alireza Shakiba
{"title":"The extraordinary atmospheric rivers analysis over the Middle East: Large-scale drivers, structure, effective sources, and precipitation characterization","authors":"Neda Esfandiari ,&nbsp;Alireza Shakiba","doi":"10.1016/j.dynatmoce.2023.101430","DOIUrl":"10.1016/j.dynatmoce.2023.101430","url":null,"abstract":"<div><p><span>The study investigates the characteristics of Extraordinary Atmospheric Rivers (EARs), including large-scale atmospheric patterns, structure, effective sources, and precipitation in the Middle East. For this purpose, ARs with maximum Vertically Integrated Water Vapor Transport (IVT) ≥ 1000 kg m</span><sup>−1</sup> s<sup>−1</sup><span> were extracted from 1981 to 2020. ERA5<span><span> and PERSIANN-CCS-CDR data were used to analyze the characteristics of the EARs. The latter was applied to show the precipitation risk level. Atmospheric patterns indicated the state of the merging cyclones. Sudan's low pressure was the more recurrent system in all the patterns and alternately integrated with one or two cyclonic tongues over the Mediterranean, the Black Sea, the Caspian Sea<span>, and then the polar vortex. </span></span>Atmospheric blocking was present in all events, affecting the lifetime of the EARs and the maximum IVT anomaly, which averaged 4.5 days and 622 kg m</span></span><sup>−1</sup> s<sup>−1</sup>, respectively. The EARs are the result of the simultaneous feeding of several moisture pathways from different sources. Both regional (mainly below 850 hPa) and trans-regional (above 700 hPa, except for the western Mediterranean) water sources played a crucial role in their formation. Dynamically, most events were characterized by merging the subtropical and polar jets, with maximum central speeds between 70 and 85 m s<sup>−1</sup><span>. EARs were also accompanied by strong near surface wind gusts up to 28 m s</span><sup>−1</sup>. In the IVT core wind structure, the low-level jet with a speed of 30 m s<sup>−1</sup> deepened to a maximum of 925 hPa. There were also intense upward velocities between − 3 and − 5 Pa s<sup>−1</sup> near the precipitation maxima areas in the EARs. The spatial character of the precipitation was of a continuous or intermittent nature, and a considerable part of it fell in short periods (up to 286 mm in 3 h). The daily maximum was 390 mm. Accordingly, the importance of using high-resolution data was represented for such events with devastating hydrological effects.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101430"},"PeriodicalIF":1.7,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139028519","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}
引用次数: 0
Assessment of marsh terrace designs for wave attenuation utilizing a wave model 利用波浪模型评估波浪衰减的沼泽梯田设计
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-22 DOI: 10.1016/j.dynatmoce.2023.101429
Raúl J. Osorio , Anna Linhoss , Adam Skarke , Michael G. Brasher , Madelyn McFarland
{"title":"Assessment of marsh terrace designs for wave attenuation utilizing a wave model","authors":"Raúl J. Osorio ,&nbsp;Anna Linhoss ,&nbsp;Adam Skarke ,&nbsp;Michael G. Brasher ,&nbsp;Madelyn McFarland","doi":"10.1016/j.dynatmoce.2023.101429","DOIUrl":"10.1016/j.dynatmoce.2023.101429","url":null,"abstract":"<div><p>The northern Gulf of Mexico is facing high rates of wetland loss due to subsidence and sea level–rise, which has encouraged the application of various wetland restoration techniques. Marsh terracing is a restoration technique that has been implemented since the early 1990 s in Texas and Louisiana, yet few studies have been conducted to evaluate its effectiveness. Marsh terraces are segmented berms of soil built in coastal ponds that were once vegetated marshes. Marsh terracing is hypothesized to dissipate wind waves, encourage marsh expansion, and reduce shoreline erosion. This study (1) assessed the effectiveness of the most common terrace shapes (linear, chevron, and square) and spacing (100, 110, and 120 m) at reducing significant wave height (Hs), (2) assessed the effectiveness of alternative terrace designs for reducing Hs during different wind conditions, and 3) estimated the construction costs of alternative terrace designs. The Simulating WAves Nearshore (SWAN) model was used to simulate wind–driven waves in ponds with real and hypothetical terrace designs. Results revealed that: (1) The chevron shape provided the greatest reduction in Hs during all wind conditions, reducing Hs by up to 54%. (2) Hs reduction was not affected by terrace spacings. (3) Based on wave attenuation, the chevron design with a 120 m terrace spacing provided the optimal outcome with an estimated construction cost/ha of $6332 in a 250,000 m<sup>2</sup> site compared to the terrace shapes and spacings evaluated in this study. This study will help coastal managers design marsh terraces to address wetland erosion in the Gulf of Mexico and other coastal areas facing similar environmental problems.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101429"},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377026523000805/pdfft?md5=744af372cb551053bfe01c68c6842e5d&pid=1-s2.0-S0377026523000805-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139028720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Geometry effects on wind fields and consequent wave generation in the Strait of Hormuz: A case study 霍尔木兹海峡风场及随之产生的波浪的几何效应:案例研究
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-22 DOI: 10.1016/j.dynatmoce.2023.101427
Fatemeh Ameri, S. Abbas Haghshenas, Sarmad Ghader
{"title":"Geometry effects on wind fields and consequent wave generation in the Strait of Hormuz: A case study","authors":"Fatemeh Ameri, S. Abbas Haghshenas, Sarmad Ghader","doi":"10.1016/j.dynatmoce.2023.101427","DOIUrl":"https://doi.org/10.1016/j.dynatmoce.2023.101427","url":null,"abstract":"<p>This study investigates the impact of surface wind forcing on wave conditions in the Strait of Hormuz, a region with complex wave interactions. The WRF model is used to simulate the wind field with higher accuracy, enabling the generation of waves for both normal and storm conditions in 2011. A sensitivity analysis examines the WRF model's simulated wind field with variations in initial and boundary conditions, spatial resolutions, and adopting two static topographic datasets. Comparisons between simulated wave parameters and observed data from ADCPs at two stations flanking the strait reveal the importance of accurate wind forcing for obtaining a realistic estimation of wave conditions. Wave errors are found to be influenced by fetch length, with larger errors observed for shorter fetches (~100<!-- --> <!-- -->km). However, these errors gradually decrease as the distance from the coast increases. The study emphasizes the importance of incorporating accurate wind data and considering fetch characteristics when simulating wave conditions, which can enhance maritime safety, coastal engineering, and offshore operations in the Strait of Hormuz and other similar regions worldwide. In conclusion, small-scale wind and waves features over the Strait of Hormuz can be better captured with a combination of higher-resolution wind modeling and wave simulation grids with higher spatial resolution.</p>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"22 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139028724","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}
引用次数: 0
Geometry effects on wind fields and consequent wave generation in the Strait of Hormuz: A case study 霍尔木兹海峡风场及随之产生的波浪的几何效应:案例研究
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-22 DOI: 10.1016/j.dynatmoce.2023.101427
Fatemeh Ameri, S. Abbas Haghshenas, Sarmad Ghader
{"title":"Geometry effects on wind fields and consequent wave generation in the Strait of Hormuz: A case study","authors":"Fatemeh Ameri,&nbsp;S. Abbas Haghshenas,&nbsp;Sarmad Ghader","doi":"10.1016/j.dynatmoce.2023.101427","DOIUrl":"10.1016/j.dynatmoce.2023.101427","url":null,"abstract":"<div><p>This study investigates the impact of surface wind forcing on wave conditions in the Strait of Hormuz, a region with complex wave interactions. The WRF model is used to simulate the wind field with higher accuracy, enabling the generation of waves for both normal and storm conditions in 2011. A sensitivity analysis examines the WRF model's simulated wind field with variations in initial and boundary conditions, spatial resolutions, and adopting two static topographic datasets. Comparisons between simulated wave parameters and observed data from ADCPs at two stations flanking the strait reveal the importance of accurate wind forcing for obtaining a realistic estimation of wave conditions. Wave errors are found to be influenced by fetch length, with larger errors observed for shorter fetches (∼100 km). However, these errors gradually decrease as the distance from the coast increases. The study emphasizes the importance of incorporating accurate wind data and considering fetch characteristics when simulating wave conditions, which can enhance maritime safety, coastal engineering, and offshore operations in the Strait of Hormuz and other similar regions worldwide. In conclusion, small-scale wind and waves features over the Strait of Hormuz can be better captured with a combination of higher-resolution wind modeling and wave simulation grids with higher spatial resolution.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101427"},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139017783","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}
引用次数: 0
Wind gust forecasting by post-processing the WRF model outputs using ANN 利用人工神经网络对 WRF 模型输出结果进行后处理,预报阵风
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-19 DOI: 10.1016/j.dynatmoce.2023.101425
Mohammad Hesam Mohammadi , Amir Hussain Meshkatee , Sarmad Ghader , Majid Azadi
{"title":"Wind gust forecasting by post-processing the WRF model outputs using ANN","authors":"Mohammad Hesam Mohammadi ,&nbsp;Amir Hussain Meshkatee ,&nbsp;Sarmad Ghader ,&nbsp;Majid Azadi","doi":"10.1016/j.dynatmoce.2023.101425","DOIUrl":"10.1016/j.dynatmoce.2023.101425","url":null,"abstract":"<div><p>Strong and highly variable winds and gusts are major hazards to infrastructure, properties, and life. Consequently, accurate prediction and timely detection of wind gust intensity have always been a focus of interest for earth scientists and weather forecasters.</p><p>In this study, The WRF (Weather Research and Forecasting) post-process diagnostic of wind gusts (WPD method) was utilized to predict non-convective wind gust speeds using the direct outputs of the WRF model. To improve the prediction accuracy of this method, the results were post-processed using an artificial neural network (ANN). Multiple different ANN algorithms were examined to achieve the most accurate predictions possible. The results were evaluated using observational data extracted from 32 synoptic stations across Iran during the time period from 2014 to 2018.</p><p><span>The results indicate that employing a multilayer perceptron<span> ANN with a hybrid structure, consisting of one input layer comprising five parameters (10 m wind speed<span>, sea level pressure, temperature, relative humidity, and predicted wind gust speed obtained from the WPD method), one hidden layer with a sigmoid activation function and 12 neurons, one output layer with a linear activation function and using the BR (Bayesian Regularization) training algorithm, significantly improve the accuracy of the WPD wind gust speed prediction method. The RMSE for wind gust speed prediction has decreased from 3.68 m/s (WPD method) to 1.88 m/s for the validation dataset. Additionally, there were considerable improvements of 50 %, 74 %, and 17 % in the MAE, MSE, and R</span></span></span><sup>2</sup>, respectively.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101425"},"PeriodicalIF":1.7,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138817319","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}
引用次数: 0
The initial errors occurring over Pacific-Atlantic Oceans and exerting large disturbing effect on ENSO predictability 太平洋-大西洋上空出现的初始误差对厄尔尼诺/南方涛动的可预测性产生了巨大的干扰作用
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-15 DOI: 10.1016/j.dynatmoce.2023.101426
Guangshan Hou , Meiyi Hou , Wansuo Duan
{"title":"The initial errors occurring over Pacific-Atlantic Oceans and exerting large disturbing effect on ENSO predictability","authors":"Guangshan Hou ,&nbsp;Meiyi Hou ,&nbsp;Wansuo Duan","doi":"10.1016/j.dynatmoce.2023.101426","DOIUrl":"10.1016/j.dynatmoce.2023.101426","url":null,"abstract":"<div><p>Using a novel data analysis method for predictability dynamics, the impacts of initial sea surface temperature<span><span> (SST) errors over Pacific and Atlantic Oceans on the predictability of eastern and central Pacific El Niño<span> (i.e., EP and CP El Niño) are investigated. The results reveal the initial SST errors that cause large disturbing effects on EP and CP El Niño forecasting, respectively. These initial errors are both exhibiting a positive-negative-positive-negative-positive chain structure along the direction from northwest to southeast over the Pacific for EP and CP El Niño, which resemble a combined mode of North Pacific Victoria Mode (VM), eastern tropical Pacific positive SST pattern (ETPPSP), and South Pacific meridional mode (SPMM); simultaneously, they exhibit a positive-negative meridional dipole pattern over South Atlantic, referred to as South Atlantic subtropical dipole mode (SASD); additionally, there exist initial warm SST anomalies in the equatorial Atlantic for </span></span>EP El Niño and in the north tropical Atlantic for the CP El Niño. The above initial errors lead to the underestimation of both CP and EP El Niño. Further analyses illustrate that the initial warm SST errors in the north tropical Atlantic are positively correlated with the VM-like error pattern, which competed with the effect of the ETPPSP, makes the intensity of CP El Niño underestimated; whereas the SASD-like error pattern is revealed to have a positive relationship with the SPMM-like error mode, which only exists during EP El Niño period and interacts with the ETPPSP for much weak EP El Niño intensity. It is obvious that, for predicting which type of El Niño will occur, attention should also be paid to the initial sea temperature accuracy in the Atlantic Ocean under the interference effect of the Pacific Ocean temperature uncertainties.</span></p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101426"},"PeriodicalIF":1.7,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138682112","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}
引用次数: 0
Three-dimensional characteristics of mesoscale eddies in the western boundary current region of the Bay of Bengal using ROMS-NPZD 利用 ROMS-NPZD 分析孟加拉湾西部边界流区域中尺度涡旋的三维特征
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-14 DOI: 10.1016/j.dynatmoce.2023.101424
Abhijit Shee , Sourav Sil , Rahul Deogharia
{"title":"Three-dimensional characteristics of mesoscale eddies in the western boundary current region of the Bay of Bengal using ROMS-NPZD","authors":"Abhijit Shee ,&nbsp;Sourav Sil ,&nbsp;Rahul Deogharia","doi":"10.1016/j.dynatmoce.2023.101424","DOIUrl":"10.1016/j.dynatmoce.2023.101424","url":null,"abstract":"<div><p><span>Eddies play an important role in transporting and redistributing the heat, salt, and biological parameters in the global ocean. In this study, three-dimensional physio-biochemical characteristics of an anticyclonic (AE) and a cyclonic eddy (CE) associated with the poleward western boundary current (WBC) in the Bay of Bengal (BoB) are analyzed using a coupled bio-physical ocean model (ROMS-NPZD). Due to eddy-induced upwelling (downwelling) associated with the CE (AE), monopole patterns of temperature and salinity<span> anomaly around the eddy center are occurred with extremum values at 100 – 150 m and 50 – 100 m depth, respectively. The upward (downward) curvature with a tip at eddy centers is observed in the isothermal layer depth, 20</span></span><span><math><mi>℃</mi></math></span> isotherm (<span><math><mrow><mi>D</mi><mn>20</mn></mrow></math></span>) nutricline, and oxycline. The depth of <span><math><mrow><mi>D</mi><mn>20</mn></mrow></math></span><span><span> deepens and shallows at the center from the edge by ∼60 m and ∼40 m for AE and CE, respectively. A relatively thick barrier layer around the center of AE is noted as compared to the CE. Within eddy interior, temperature and salinity tendencies of horizontal advection<span> show a strong dipole pattern with extremum at eddy edges. The AE currents show positive tendencies in horizontal advection of temperature (salinity) at its northeastern (southwestern) side, which is totally opposite to that of CE. Intense horizontal advections in the adjacent flanks of eddies to the eastward jet of the WBC are due to their strong interactions. Vertical advection shows a </span></span>quadrupole<span> structure with alternating positive and negative cells within the eddies following the distorted vertical velocity field. Diffusion terms within eddies are quite small compared to the advection. Abundances of chlorophyll-a (∼1.2 mg/m</span></span><sup>3</sup>) at the base of the mixed layer around the CE center are absent for the AE.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101424"},"PeriodicalIF":1.7,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138745807","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}
引用次数: 0
Tendencies of tropical cloud clusters transformation into tropical cyclones 热带云团转变为热带气旋的趋势
IF 1.7 4区 地球科学
Dynamics of Atmospheres and Oceans Pub Date : 2023-12-12 DOI: 10.1016/j.dynatmoce.2023.101423
Kandula V. Subrahmanyam , Karanam Kishore Kumar , D.R. Pattanaik , M.V. Ramana , Prakash Chauhan
{"title":"Tendencies of tropical cloud clusters transformation into tropical cyclones","authors":"Kandula V. Subrahmanyam ,&nbsp;Karanam Kishore Kumar ,&nbsp;D.R. Pattanaik ,&nbsp;M.V. Ramana ,&nbsp;Prakash Chauhan","doi":"10.1016/j.dynatmoce.2023.101423","DOIUrl":"10.1016/j.dynatmoce.2023.101423","url":null,"abstract":"<div><p><span>Tropical cloud clusters (TCC) play a vital role in Earth's climate by not only releasing a large amount of latent heat into the atmosphere but also by forming the basis for the development of tropical cyclones (TC). However, not all TCCs can develop into cyclones; only a few develop into TC selectively. There are large uncertainties in the current understanding of why only certain TCCs develop into TC while others don't. The present study employs global TCC observations generated by GridSat and IBTrACS datasets from 1980 to 2009 to investigate the TCC distributions over various Oceanic basins such as the North Atlantic (NA), South Atlantic (SA), East-West and South Pacific (EP, WP and SP), as well as the North Indian (NI) and South Indian (SI) basins. The central objective of the present study is to characterize the size spectrum of TCCs and investigate their potential transformation into TCs. The TCCs are identified based on different IR temperature thresholds in each basin. The present results suggest that ∼ 5.5 % of TCCs were developed into TCs annually globally, and their trends in each oceanic basin are discussed. The size spectrum of TCCs showed a dominant peak at 100–200 km</span><sup>2</sup><span>. About 48 % of TCCs transform into TCs within 24 hr of being identified. Furthermore, 85 % of TCCs develop into TCs within 84 hr of the first identification, while only 5 % of TCCs develop into TCs after 84 hr. Further, we have also analyzed the background environmental conditions such as low-level wind speed, vorticity, divergence, vertical shear, upper-level relative humidly and latent heating (LH) for developing and non-developing TCCs over the NI basin, which have not been explored in detail in earlier studies. It is noted that the relative humidity in the developing composite is around 10–20 % higher than that in non-developing TCCs, and LH in developing TCCs is 0.15 K/hr, larger than that in non-developing TCCs. The significance of the present study lies in investigating the developing TCCs as a function of their size and lifetime, including their long-term trends, and bringing out favourable environmental conditions for developing TCCs in the NI Ocean.</span></p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"105 ","pages":"Article 101423"},"PeriodicalIF":1.7,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138682414","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}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信