Dynamics of Atmospheres and Oceans最新文献_第6页

The North Atlantic subpolar ocean dynamics during the past 21,000 years 过去 21,000 年北大西洋次极地海洋动力学

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-05-13 DOI: 10.1016/j.dynatmoce.2024.101462

Gagan Mandal , Amali I. Hettiarachchi , Shail V. Ekka

{"title":"The North Atlantic subpolar ocean dynamics during the past 21,000 years","authors":"Gagan Mandal , Amali I. Hettiarachchi , Shail V. Ekka","doi":"10.1016/j.dynatmoce.2024.101462","DOIUrl":"10.1016/j.dynatmoce.2024.101462","url":null,"abstract":"<div><p>Numerous studies have suggested that the North Atlantic subpolar gyre (SPG), Atlantic Meridional Overturning Circulation (AMOC), and Arctic sea ice impact the polar and global climate. Here, we use a fully linked atmosphere-ocean-sea ice Earth system model to investigate the North Atlantic subpolar ocean dynamics over the last 21 thousand years before the present (ka). We found that the SPG strength, net ocean surface heat flux, and mixed layer depth in the North Atlantic deep convection sites declined during the Heinrich 1 (H1; ∼19–17 ka) and Younger Dryas (YD; ∼12.9–11.3 ka) cold events. Consequently, the deep convection and AMOC strength declined, reducing the northward meridional heat transport and causing the expansion of Atlantic sea ice coverage. We also found that the North Atlantic subpolar net ocean surface heat flux varied coherently with AMOC strength throughout the past 21 ka. Subsequently, we observed a sea ice-capping mechanism wherein an increase (decrease) in Atlantic sea ice coverage during H1/YD (Bølling-Allerød (BA; ∼17–14.35 ka)) reduces (increases) net ocean surface heat flux and deep convection, thereby influencing the AMOC strength. Meanwhile, the SPG and AMOC strengths have been in-phase throughout the past 21 ka, except during the abrupt termination and input of freshwater flux during the BA and Meltwater Pulse 1 A (∼14.4–13.9 ka) events, respectively. In conclusion, our study suggests that a sudden shift in freshwater discharge into the subpolar North Atlantic may disturb the polar ocean dynamics.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101462"},"PeriodicalIF":1.7,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141034320","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

Current and density observations on a flow through a contraction and over a bottom elevation at the southern edge of the Cycladic Plateau in the Aegean Sea – East Mediterranean 对爱琴海基克拉泽斯高原南缘通过收缩区和海底高地的水流和密度观测 - 东地中海

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-04-26 DOI: 10.1016/j.dynatmoce.2024.101460

Harilaos Kontoyiannis , Larry J. Pratt , Vassilis Zervakis , Mathew H. Alford , Sarantis Sofianos , Alexander Theocharis

{"title":"Current and density observations on a flow through a contraction and over a bottom elevation at the southern edge of the Cycladic Plateau in the Aegean Sea – East Mediterranean","authors":"Harilaos Kontoyiannis , Larry J. Pratt , Vassilis Zervakis , Mathew H. Alford , Sarantis Sofianos , Alexander Theocharis","doi":"10.1016/j.dynatmoce.2024.101460","DOIUrl":"https://doi.org/10.1016/j.dynatmoce.2024.101460","url":null,"abstract":"<div><p>A CTD/ADCP/surface-drifter survey in fall 2004 reveals the behaviour of a mesoscale unidirectional flow coming from the Cretan sea in the south with depths ∼1000 m and entering a channel-like area of the Cycladic shelf in the north, that forms a contraction which leads to a bottom elevation (sill depth ∼100 m), and finally returning into the Cretan Sea in the lee-side of the sill. The flow decelerates/accelerates upstream/downstream of the sill. The along-stream density contours near the sill bottom are raised prior to reaching the sill, while they deepen in the lee side of it indicating supercriticality. The long-wavelength internal wave speeds with realistic stratification and no-rotation are higher than the section averaged flow speeds and indicate subcriticality. A key element in this apparent paradox is the large height of the sill that potentially increases the body (drag) force exerted on the flow by the sill while flow blocking is also observed upstream of the sill.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101460"},"PeriodicalIF":1.7,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140825384","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

A fractal approach to ocean Ekman transport 海洋埃克曼输运的分形方法

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-04-23 DOI: 10.1016/j.dynatmoce.2024.101459

Rami Ahmad El-Nabulsi , Waranont Anukool

引用次数: 0

The analytical solutions of long waves over geometries with linear and nonlinear variations in the form of power-law nonlinearities with solid inclined wall 以幂律非线性形式的线性和非线性变化与固体倾斜壁上长波的解析解

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-04-13 DOI: 10.1016/j.dynatmoce.2024.101458

Ali Rıza Alan , Cihan Bayındır

引用次数: 0

Developmental mechanism of the SWCV nonlinear inertial waves SWCV 非线性惯性波的发展机制

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-04-04 DOI: 10.1016/j.dynatmoce.2024.101457

Chun Liu , Yueqing Li , Jun Sun , Yunlong Zhao , Jiaqi Yu

{"title":"Developmental mechanism of the SWCV nonlinear inertial waves","authors":"Chun Liu , Yueqing Li , Jun Sun , Yunlong Zhao , Jiaqi Yu","doi":"10.1016/j.dynatmoce.2024.101457","DOIUrl":"https://doi.org/10.1016/j.dynatmoce.2024.101457","url":null,"abstract":"<div><p>Based on the Boussinosq Approximation formulas in the symmetric, cylindric coordinates, the nonlinear effects of the internal inertial gravity waves on the meso-micro scale convective activities of Southwest China Vortex system are analyzed by the multi-scale and perturbation approximation methods. The results obtain two main conclusions: (1) When the atmospheric stratification is stable, the inertial gravity waves for Southwest China Vortex may also develop into finite-amplitude wave packet with a solitonic characteristics of large amplitude and short duration, forming a long-narrow wave band which activates and organizes severe convective activities like high wind and thunderstorm of Southwest China Vortex. When the atmospheric stratification is unstable, the inertial gravity waves exhibits attenuating oscillation characteristics and develops into finite-amplitude wave packet with large amplitude and fast speed, forming queue-type wave band that activates and organizes extreme weather like persistent heavy rainfall of Southwest China Vortex. (2) Under different atmospheric stratifications, the effects of thermal forcing on the inertial gravity waves for Southwest China Vortex are different. In the stable atmospheric stratification, the thermal forcing mainly intensifies the inertial gravity waves and has no significant effect on its duration. And in the unstable atmospheric stratification, the thermal forcing not only strengthens its growth but also obviously extends its duration. The research has revealed the some nonlinear characteristics of the internal inertial gravity waves for Southwest China Vortex, and improved the theoretical understanding about the critical role of the internal inertial gravity waves dynamic processes and its influence mechanism on the meso-micro scale severe convection weather for Southwest China Vortex.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101457"},"PeriodicalIF":1.7,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377026524000253/pdfft?md5=9e3d1b34a0176002165f9b88a13fed25&pid=1-s2.0-S0377026524000253-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140551772","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

Intercomparison of tropical Indian Ocean circulation in ocean reanalysis and evaluation in CMIP6 climate models 海洋再分析中热带印度洋环流的相互比较和 CMIP6 气候模式的评估

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-03-21 DOI: 10.1016/j.dynatmoce.2024.101456

P. Bhanu Deepika , Soumya Mohan , G. Srinivas

{"title":"Intercomparison of tropical Indian Ocean circulation in ocean reanalysis and evaluation in CMIP6 climate models","authors":"P. Bhanu Deepika , Soumya Mohan , G. Srinivas","doi":"10.1016/j.dynatmoce.2024.101456","DOIUrl":"10.1016/j.dynatmoce.2024.101456","url":null,"abstract":"<div><p>In the present study, we assess the Tropical Indian Ocean (TIO) circulation features from the available ocean reanalysis products and the latest version of Coupled Model Intercomparison Project (CMIP6) climate model simulations. We considered the following reanalysis products; Ocean Reanalysis System 5 (ORAS5), Estimating the Circulation and Climate of the Ocean (ECCO), Global Ocean Data Assimilation System (GODAS), Ensemble Coupled Data Assimilation (ECDA), the Bluelink Reanalysis (BRAN) and Simple Ocean Data Assimilation (SODA) and compared them against in-situ observations and the satellite-derived Ocean Surface Current Analyses Real-time (OSCAR). The reanalysis products underestimate the strength and location of the Wyrtki Jets. The BRAN reanalysis performed well compared to the other products in representing the TIO surface zonal currents, followed by ORAS5. The vertical extension of subsurface zonal currents in the equatorial Indian Ocean and their seasonal maxima are well captured in ORAS5. Thus, our analysis suggests that the ORAS5 is a qualitative product to estimate the TIO circulation. We further evaluated the TIO current patterns simulated by CMIP6 models with in-situ data/ ORAS5. The majority of the models show discrepancies in simulating equatorial and south equatorial current systems with a mean bias of 0.1cms<sup>−1</sup> and 0.2cms<sup>−1,</sup> respectively. NorESM2-MM, NorESM2-LM, CanESM5, CESM2-WACCM-FV2, and E3SM-1-ECA models showed a superior skill in reproducing the TIO circulation compared to the rest of the models. Our analysis highlights the importance of assessing various reanalysis products and coupled climate models in representing the circulation of the TIO and, consequently, their role in depicting regional weather and climate.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101456"},"PeriodicalIF":1.7,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140272558","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

Investigating the possibilities of temperature concentration distribution in Zayanderood based on climate change 根据气候变化调查扎扬德鲁德温度浓度分布的可能性

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-03-19 DOI: 10.1016/j.dynatmoce.2024.101454

Mohammad Nazeri Tahroudi , Rasoul Mirabbasi , Aliheidar Nasrolahi

{"title":"Investigating the possibilities of temperature concentration distribution in Zayanderood based on climate change","authors":"Mohammad Nazeri Tahroudi , Rasoul Mirabbasi , Aliheidar Nasrolahi","doi":"10.1016/j.dynatmoce.2024.101454","DOIUrl":"https://doi.org/10.1016/j.dynatmoce.2024.101454","url":null,"abstract":"<div><p>In this study, temperature changes and its concentration distribution in the period of 1984–2015 and 2015–2100 were investigated under CanESM5 climate model and SSP126, SSP245 and SSP585 scenarios. By confirming the correlation (more than 0.96) and the efficiency coefficient of the model (more than 0.82), the trend of temperature values using modified Mann-Kendall test and temperature concentration index (TCI) values in the sub-basins of Zayanderood Dam, Iran was estimated. The results indicated a non-significant upward trend in the base period (1984–2015) and a significant increasing trend at the level of 5% in the future period (2015–2100) produced by the mentioned scenarios. According to the slope of the trend line, an increase of 1.45, 4 and 9.8 degrees Celsius is predicted during the period of 2015–2100 according to the SSP126, SSP245 and SSP585 scenarios, respectively. The evaluation of changes in TCI values in the studied area showed that in the future period, the distribution of rainfall patterns will be regular and the uniformity of temperature distribution in the SSP585 scenario is more than in the other two scenarios. The results of the temperature pattern distribution in the study area showed that according to the upcoming climate changes and under the studied scenarios, it is expected that while the study area is warming in the future, the uniformity of the temperature distribution will also appear in the months of the year. This shows the reduction of temperature fluctuations and the uniformity of the average temperature in the months of the year. The reduction of TCI values shows the equalization of average temperature changes in the seasons. The results of the investigations showed that the combination of climate change scenarios with the TCI can well show the concentration and distribution of the temperature in different periods.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101454"},"PeriodicalIF":1.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140191738","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

Evaluating the climatic state of Indian Summer Monsoon during the mid-Pliocene period using CMIP6 model simulations 利用 CMIP6 模型模拟评估上新世中期印度夏季季风的气候状况

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-03-17 DOI: 10.1016/j.dynatmoce.2024.101455

Karishma Dahiya , Nagaraju Chilukoti , Raju Attada

{"title":"Evaluating the climatic state of Indian Summer Monsoon during the mid-Pliocene period using CMIP6 model simulations","authors":"Karishma Dahiya , Nagaraju Chilukoti , Raju Attada","doi":"10.1016/j.dynatmoce.2024.101455","DOIUrl":"10.1016/j.dynatmoce.2024.101455","url":null,"abstract":"<div><p>The Indian Summer Monsoon Rainfall (ISMR) plays a critical role in agriculture, thereby significantly affecting the economy of India. Yet, there is a large spread in the ISMR variability for future projections (by the end of 21st century) as simulated by coupled general circulation models. Gaining insight into the variations of the ISMR during warm periods could enhance our ability to understand ISMR variability in the future. In this study, we have selected the mid-Pliocene warm period from 3.0 to 3.3 million years ago (Ma), which has similar external forcing (orbital parameters) comparable to the end of the 21st century. To evaluate the ISMR mean state during the mid-Pliocene, we have used six available Coupled Model Intercomparison Project phase 6 (CMIP6) model simulations and their multi-model ensemble mean. Our analysis suggests that the ensemble of CMIP6 models is better than individual models in capturing the ISM rainfall patterns and its characteristics for the historical period of 1914–2013. During the mid-Pliocene, we find an increase in the JJAS rainfall over most parts of India in comparison to the pre-industrial period with an increase of 34% in seasonal precipitation. This higher precipitation conditions during the mid-Pliocene is accompanied by thermo dynamical (higher CO<sub>2</sub> forcing led to higher tropospheric temperature and higher precipitable water) and dynamical (larger tropospheric temperature gradient between Indian landmass and southern Indian Ocean corresponds to enhanced moisture transport, enhanced low-level cross-equatorial flow and intensified Monsoon Hadley Circulation) aspects.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101455"},"PeriodicalIF":1.7,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140201424","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

Decoding low-frequency climate variations: A case study on ENSO and ocean surface warming 解码低频气候变异：厄尔尼诺/南方涛动和海洋表面变暖案例研究

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-03-02 DOI: 10.1016/j.dynatmoce.2024.101453

Rameshan Kallummal

{"title":"Decoding low-frequency climate variations: A case study on ENSO and ocean surface warming","authors":"Rameshan Kallummal","doi":"10.1016/j.dynatmoce.2024.101453","DOIUrl":"https://doi.org/10.1016/j.dynatmoce.2024.101453","url":null,"abstract":"<div><p>Current perspectives on lower frequency variations and secular warming have predominantly been shaped by traditional anomalies that assume an annual cycle (AC) with a time-invariant amplitude. However, this anomaly framework falls short in capturing the complexity of multiple periodic modes with intricate waveforms and time dependent amplitude—the traits, in general, shared by externally forced responses of complex dynamical systems. By allowing interannual amplitude modulation of ACs, we show that the monotonic amplitude increases of the first AC of Sea Surface Temperature (SST) are manifested as the basin-wide secular warming of the ocean surface. Notably, the first SST-AC exhibits significant interannual variances and the largest linear warming rates in the Pacific Warm Pool. While the linear warming pattern mirrors that of a long-term mean SST, it depicts an entirely different warming pattern on the surface of the tropical Pacific Ocean compared to those reported so far. Moreover, all interannual warm (El Niño) and cold (La Niña) events in tropical Pacific regions are abnormal interannual modulations in the third and fourth ACs of SST, respectively. Specifically, a strong El Niño event occurs when a positive amplitude modulation leads to the overlap of two consecutive positive phases of the third AC of SST. Conversely, the absence of such overlaps during negative amplitude modulations significantly contributes to the positive skewness of SST anomalies. No systematic decadal changes in the zonal propagation characteristics of SST in the eastern Pacific (EP) and central Pacific (CP) regions were detected. These findings underscore that the secular warming and low-frequency events in EP and CP are intrinsic to three distinct ACs.</p></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"106 ","pages":"Article 101453"},"PeriodicalIF":1.7,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140052609","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

Corrigendum to “On the phenology of coastal upwelling off central-southern Chile” [Dyn. Atmos. Oceans 104 (2023) 1–17] 智利中南部沿海上升流物候 "更正[Dyn. Atmos. Oceans 104 (2023) 1-17]

IF 1.7 4区地球科学

Dynamics of Atmospheres and Oceans Pub Date : 2024-02-28 DOI: 10.1016/j.dynatmoce.2024.101447

Richard Muñoz , Odette A. Vergara , Pedro A. Figueroa , Piero Mardones , Marcus Sobarzo , Gonzalo S. Saldías

引用次数: 0