Abstract The signatures of mesoscale eddies induced surface and subsurface changes have not been comprehensively quantified for the Bay of Bengal (BoB) region. This study quantifies the statistical properties and three-dimensional (3D) eddy structures in the BoB. To accomplish this, the satellite altimetry data combined with automated eddy detection and tracking algorithm is used. Horizontal distribution of surface characteristics of eddies is analyzed by using 24 years (1993–2016) of AVHRR infrared satellite sea surface temperature (SST) and 7 years (2010–2016) of sea surface salinity (SSS) of SMOS satellite data. Surface eddy centric composite analysis reveals the existence of warm (cold) and diverse SSS anomalies for anticyclonic (cyclonic) eddies. During winter, it is important to note that the eddy induced SST and SSS anomalies show the dipole patterns show opposite phases for the cyclonic and anticyclonic eddies. Observed diploe structures are consistent with the eddy rotation and background large-scale meridional gradient of temperature and salinity fields. The 3D structure of eddies is investigated by using the ARMOR3D and Argo float profiles. The horizontal distribution of temperature and salinity anomalies from ARMOR3D signify the monopole structure of eddies in the subsurface layers. Further, the analysis of composite averages of 241 (200) Argo temperature profiles indicates the core of anticyclonic (cyclonic) eddies centered at about ∼140 m (∼100 m). However, salinity profiles depict the existence of core at ∼65 m (∼50 m). This study have practical relevance to a variety of stakeholders and finds profound importance in the validation of eddy-resolving ocean models for the BoB region.

中文翻译：

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孟加拉湾大洋中尺度涡旋特征及垂向结构

摘要 尚未对孟加拉湾 (BoB) 地区的中尺度涡旋引起的地表和地下变化的特征进行全面量化。这项研究量化了 BoB 中的统计特性和三维 (3D) 涡流结构。为了实现这一点，使用了卫星测高数据与自动涡流检测和跟踪算法相结合。利用AVHRR红外卫星海面温度（SST）24年（1993-2016）和SMOS卫星海面盐度（SSS）7年（2010-2016）数据，分析涡旋表面特征水平分布。表面涡心复合分析揭示了反气旋（气旋）涡流存在暖（冷）和不同的 SSS 异常。在冬天，重要的是要注意涡流引起的 SST 和 SSS 异常显示偶极子模式显示气旋和反气旋涡旋的相反相位。观测到的双叶结构与温度和盐度场的涡旋和背景大尺度子午梯度一致。使用 ARMOR3D 和 Argo 浮动剖面研究涡流的 3D 结构。来自 ARMOR3D 的温度和盐度异常水平分布表明地下层涡流的单极结构。此外，对 241 (200) 个 Argo 温度剖面的复合平均值的分析表明，反气旋（气旋）涡旋的核心集中在约 140 m（约 100 m）处。然而，盐度剖面描述了约 65 m（约 50 m）处岩心的存在。