Abstract Frequently-forming long-life mesoscale eddies are observed in the Algerian Basin that influence the circulation of the wider Western Mediterranean Sea. Most of these structures store and transport water masses including associated physical and biological properties throughout the entire basin. In order to study the evolution of a long-life anticyclonic eddy, we use a multiplatform approach based on remote sensing data analysis and in situ measurements. We present a case study of an anticyclonic eddy that persisted for 17 months within the basin. The feature was identified through a hybrid method of eddy detection and tracking applied to altimetry data, and sampled twice during two different oceanographic cruises in autumn 2004 and late spring 2005. Transect observations of potential temperature, salinity, density and the dissolved oxygen concentration were utilised to infer water mass properties and eddy characteristics. In situ data show that water of Atlantic origin, initially trapped by the eddy during its formation, was modified during the eddy lifetime. The time evolution of radius, kinetic energy and vorticity suggests dividing the eddy lifetime into three phases: the eddy formation, an intermediate period of high variability and a final, lower energy phase. The track followed by the eddy confirms the hypothesis of an interaction with the North Balearic Front and a consequent change of the eddy's physical properties. Decomposing the eddy's kinetic energy into mean and fluctuating terms allows us to describe its interaction with the mean circulation of the basin. In particular during formation, the southern part of the eddy absorbs energy from the mean circulation, while it provides energy to the mean flow in its northern part. In the second phase, when the eddy is far from the coast, it receives energy from the mean flow. Combining in situ data analysis with the results of the satellite-imagery-based detection and tracking method has proven to be a very useful method in assessing the evolution of a mesoscale structure in the Algerian Basin and its interaction with the large scale ocean dynamics of the Western Mediterranean Sea.

中文翻译：

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来自测高数据、跟踪算法和原位观测的阿尔及利亚盆地反气旋涡旋的生命史。

摘要 在阿尔及利亚盆地观察到频繁形成的长寿命中尺度涡旋，影响更广阔的西地中海环流。大多数这些结构在整个流域内储存和运输水团，包括相关的物理和生物特性。为了研究长寿命反气旋涡流的演变，我们使用了基于遥感数据分析和原位测量的多平台方法。我们展示了一个在盆地内持续了 17 个月的反气旋涡流的案例研究。该特征是通过应用于高度测量数据的涡流检测和跟踪的混合方法确定的，并在 2004 年秋季和 2005 年春末的两次不同海洋航行中采样了两次。密度和溶解氧浓度被用来推断水的质量特性和涡流特性。原位数据显示，起源于大西洋的水，最初在其形成过程中被涡流困住，但在涡流寿命期间发生了变化。半径、动能和涡度的时间演变表明将涡流寿命分为三个阶段：涡流形成、高可变性的中间阶段和最终的低能量阶段。涡流跟随的轨迹证实了与北巴利阿里锋相互作用以及涡流物理特性随之发生变化的假设。将涡流的动能分解为平均和波动项，我们可以描述其与盆地平均环流的相互作用。尤其是在形成过程中，涡流的南部从平均环流吸收能量，同时为北部的平均流提供能量。在第二阶段，当涡流远离海岸时，它从平均流接收能量。将原位数据分析与基于卫星图像的检测和跟踪方法的结果相结合已被证明是评估阿尔及利亚盆地中尺度结构演化及其与大尺度海洋动力学相互作用的一种非常有用的方法。西地中海。