Objectives: This study intends to describe the Andaman Sea circulation and investigate the dominant modes of variability in the basin. Analysis/Observations: The domain experiences stronger South-westerly winds from May to September and relatively weaker North-easterlies from November to February. A strong negative Ekman pumping along the north coast of Indonesia is observed during Summer. The transport of water across the straits of Andaman and Nicobar Islands (ANI) is computed by simple mass balance and is found to be in phase with the monthly averaged Mean Sea Level Anomalies (MSLA) of Andaman Sea. There occurs high surface outflux through Great channel and Ten-Degree channel in Summer. In April and October, rate of transport through the straits is maximum. During the same months, meridional surface currents intensify along the eastern boundary of the basin and are associated with signatures of downwelling. Findings: Intense down welling occurs to the north coast of Indonesia during Summer, locally forced by south-westerlies. There occurs large influx of water into Andaman Sea between April and November through the straits between the islands. Equatorial Wyrtki jets remotely force Kelvin waves of downwelling nature in the basin during April and October. The circulation in Andaman Sea is characterised by gyres or vortices, which is the manifestation of Rossby waves of semi-annual mode. The basin has a characteristic 120-day mode of westward propagating long Rossby wave packets which reflect from the coast of ANI as eastward propagating short Rossby waves. Novelty: The first attempt to completely describe the dynamics of Andaman Sea circulation exclusively from observations.
Zonal-mean circulation response to reduced air-sea momentum roughness
表层物理学的不确定性对大气环流的影响相对来说还没有被探索。本文用社区大气模式(CAM 3)研究了低流速时纬向平均环流对减小的海气动量粗糙度($Z_{0m}$)的敏感性。在一个具有指定海面温度的水行星框架中,对$Z_{0m}$减少的响应类似于La Ni $\tilde{\text{n}}$ a减去El Ni $\tilde{\text{n}}$ o对El Ni $\tilde{\text{n}}$ o南方涛动变率的响应,其中:i)中纬度西风带向极移动,一直延伸到地面; ii)副热带下降区向极移动较弱;及iii)哈德利环流减弱,一般亦伴随着热带会聚区及热带地面东风带向极移。机制否认实验表明,这种响应是由热带潜热和感热通量的减少,减少$Z_{0m}$的影响。通过考虑热带能量通量对Hadley环流强度、对流层上部临界层纬度和对流层下部斜压涡动强迫的影响,阐明了环流响应。ITCZ的转变是通过在热带湿静态能量收支分析。环流对减少的$Z_{0m}$的响应延续到更复杂的设置,具有季节性周期,大气-冰-陆地-海洋相互作用的完全复杂性,以及板状海洋下边界条件。因此,表面参数化参数的相对较小的变化可以导致显著的环流响应。
Density and sea level changes weaken the Atlantic Meridional Overturning Circulation through ocean bottom pressure
Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami(迈阿密大学罗斯恩施泰尔海洋、大气和地球科学学院);National Oceanography Centre, Southampton(南安普敦国家海洋中心)
Marine Heatwaves in the Arabian Sea: Drivers and Impacts on Atmospheric Circulation and Extreme Precipitation
University of Colorado, Boulder(科罗拉多大学博尔德分校);Texas A&M University–Corpus Christi(德克萨斯农工大学科珀斯克里斯蒂分校);Scripps Institution of Oceanography, University of California, San Diego(加州大学圣地亚哥分校斯克里普斯海洋研究所);Florida State University(佛罗里达州立大学)
Air-Sea Interactions on Titan: Lake Evaporation, Atmospheric Circulation, and Cloud Formation
泰坦丰富的湖泊和海洋通过一种通常被称为空气-海洋相互作用的过程与大气交换甲烷蒸汽和能量。这种湍流交换过程的研究与大气中尺度模式耦合到一个平板模式表示下垫面湖泊。通过几十个二维数值模拟,研究了湖泊尺度、有效湖混合层深度、背景风速、气湖温差和大气湿度对海气相互作用过程的影响。一般的,准稳定的解决方案是一个非常弱的背景羽流环流驱动的浮力蒸发的甲烷与一个强大的相反的热直接(海风)环流驱动的湖泊和温暖的内陆空气之间的热对比的非线性叠加。具体的解决方案取决于所选择的大气和湖泊属性参数的值,但这两个环流的叠加的一般解决方案是持久的。与前人的分析工作相一致,感热通量和潜热通量趋向于相反和相等的值,使得它们的比值Bowen比在大多数(但不是全部)准稳态解中接近-1.0。重要的是,在几乎所有的情况下,通量的绝对星等的趋势非常小的值,这样的平衡解决方案也几乎是一个平凡的解决方案,其中海气能量交换约3 W m-2或less. In所有情况下,一个凉爽,潮湿,静态稳定的浅海层,近平静的风和小湍流通量交换与一个较冷的底层湖泊产生的模型。湖泊的温度、空气的海洋属性和海风的强度取决于初始条件,在较小程度上取决于边界条件。
Climate and ocean circulation changes toward a modern snowball Earth
Japan Agency for Marine-Earth Science and Technology(日本海洋地球科学技术局);Earth-Life Science Institute (ELSI), Institute of Future Science, Institute of Science Tokyo(东京科学大学未来科学研究所生命起源研究所);Atmosphere and Ocean Research Institute, The University of Tokyo(东京大学大气海洋研究所);University of the Ryukyus(冲绳大学);Department of Geophysics, Graduate School of Science, Tohoku University(东北大学理学研究科地球物理学科);National Institute of Polar Research(国立极地研究所);The Graduate University for Advanced Studies, SOKENDAI(综合研究大学院大学)
Meridional energy transport extremes and the general circulation of Northern Hemisphere mid-latitudes: dominant weather regimes and preferred zonal wavenumbers
Multi-scale decomposition of sea surface height snapshots using machine learning
Columbia University(哥伦比亚大学);New York University(纽约大学);Lamont Doherty Earth Observatory(拉蒙特-多尔蒂地球观测所);Applied Physics and Applied Mathematics(应用物理与应用数学学院);Courant Institute(柯朗研究所)
Advancing Seasonal Prediction of Tropical Cyclone Activity with a Hybrid AI-Physics Climate Model
University of Illinois at Urbana-Champaign(伊利诺伊大学厄巴纳-香槟分校);Google Research(谷歌研究院);Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration(美国国家海洋和大气管理局地球流体动力学实验室)
Deep Learning Atmospheric Models Reliably Simulate Out-of-Sample Land Heat and Cold Wave Frequencies
Department of Atmospheric and Climate Science, University of Washington(大气科学与气候系,华盛顿大学);Department of Geosciences, Princeton University(地球科学系,普林斯顿大学);High Meadows Environmental Institute, Princeton University(普林斯顿大学高地环境研究所)