当前位置: X-MOL 学术Ocean Dyn. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Characteristics of topographic submesoscale eddies off the Crimea coast from high-resolution satellite optical measurements
Ocean Dynamics ( IF 2.2 ) Pub Date : 2021-04-22 , DOI: 10.1007/s10236-021-01458-9
Anna Aleskerova , Arseny Kubryakov , Sergey Stanichny , Alessia Medvedeva , Evgeniy Plotnikov , Artem Mizyuk , Liudmila Verzhevskaia

Long-term arrays of satellite optical measurements of Landsat-5,7,8 and Sentinel-2 were used to describe the characteristics of submesoscale eddy (SE) dynamics in different parts of the Crimean coast: their geometric and kinematic characteristics, the main sites and mechanisms of formation, and impact on the redistribution of suspended matter. The dynamic characteristics of SE were computed on the base of the 4D variational assimilation method from the pair of consecutive Landsat-8/Sentinel-2 images. The orbital velocity of submesoscale cyclonic eddies (SCE) with a diameter of 1 km reaches 0.15 m/s, indicating the cyclostrophic balance with a high Rossby number (RO) exceeding 2. Submesoscale cyclones were detected much more frequently than the usually larger submesoscale anticyclones. High-resolution satellite imagery gives a possibility to observe complex submesoscale dynamic processes, such as the generation of chains of SCE, large cyclones behind the capes consisting of densely packed arrays of SCEs, topographic submesoscale anticyclones with a number of attached SCEs, mushroom-like current structures, and frontal SE. Despite the diversity of the processes considered, several basic mechanisms of formation of submesoscale eddies can be identified on the basis of satellite data: (1) Separation of the boundary current, often wind-driven, behind the capes; (2) barotropic instability due to the horizontal shear on the coastal periphery of mesoscale anticyclones or alongshore currents; (3) formation of the mushroom-like structure due to the interaction of offshore currents with deep waters near the capes or due to offshore winds; and (4) frontal instabilities on the coastal upwelling. The results of the analysis were used to create a scheme of the spatial variability of submesoscale processes near the Crimean coast and compare it to the results of the high-resolution modeling. The model was able to describe the main areas of SE formation, which was located near the major capes. It provides additional data about SE generation near the rocky capes of the South Crimea, where satellite data was limited by the absence of optical tracers.



中文翻译:

高分辨率卫星光学测量得出的克里米亚沿海地形的亚中尺度涡旋的特征

使用Landsat-5、7、8和Sentinel-2的卫星光学测量的长期阵列来描述克里米亚海岸不同地区的亚中尺度涡(SE)动力学特征:其几何和运动学特征,主要地点的形成机制,以及对悬浮物再分配的影响。从4对连续Landsat-8 / Sentinel-2图像中,基于4D变分同化方法,计算了SE的动态特征。直径为1 km的亚中尺度旋风涡(SCE)的轨道速度达到0.15 m / s,这表明高罗斯比数(RO)超过2的环营养平衡。 。高分辨率卫星图像使您有可能观察到复杂的亚中尺度动态过程,例如SCE链的生成,由密集堆积的SCE阵列组成的海角后面的大型旋风,带有许多附着SCE的地形亚中尺度反旋风,像蘑菇一样当前的结构和正面SE。尽管所考虑的过程各不相同,但仍可以根据卫星数据确定形成亚中尺度涡流的几种基本机制:(1)分离在海角后面的边界电流,通常是风驱动的;(2)由于中尺度反气旋沿海边缘或沿岸洋流的水平剪切所致的正压失稳;(3)由于近海流与海角附近深水的相互作用或近海风而形成的蘑菇状结构;(4)沿海上升流的前缘不稳定性。分析结果用于创建克里米亚海岸附近亚中尺度过程空间变异性的方案,并将其与高分辨率建模结果进行比较。该模型能够描述SE形成的主要区域,这些区域位于主要海角附近。它提供了有关南克里米亚岩石海角附近SE生成的其他数据,那里的卫星数据由于缺少光学示踪剂而受到限制。位于主要海角附近。它提供了有关南克里米亚岩石海角附近SE生成的其他数据,那里的卫星数据由于缺少光学示踪剂而受到限制。位于主要海角附近。它提供了有关南克里米亚岩石海角附近SE生成的其他数据,那里的卫星数据由于缺少光学示踪剂而受到限制。

更新日期:2021-04-22
down
wechat
bug