Based on hydrographic data from two cruises (June 2010 and May 2012) off Baja California Sur, Mexico, historical measurements from the World Ocean Database 2018, California Cooperative Oceanic Fisheries Investigations, and Investigaciones Mexicanas de la Corriente de California cruise programs, as well as satellite images and data from the Global Reanalysis, this study describes the California Current System off Baja California Sur. The California Current System is characterized by the interaction of four near-surface currents. Far from the coast, the California Current flows within the North Pacific Subtropical Gyre but does not reach the Pacific Tropical-Subtropical Convergence off Mexico. From December to June, an equatorward flow known as the Tropical Branch of California Current emerges along the coast. This flow intensifies from March to June and is closely related to the mass flux induced by coastal upwelling. In July, a new branch of the Tropical Branch of the California Current turns poleward along the Baja California Sur coast. This flow is often referred to as the California Surface Countercurrent because it flows in the opposite direction to the California Current. Additionally, the California Undercurrent is detected, influencing the water column from 100 to 900 m, with a maximum poleward flow between 200 m and 300 m, decreasing toward the surface. The California Undercurrent persists throughout the year over the continental slope, displaying a significant semiannual component around the Gulf of California entrance. The California Current System off Baja California Sur plays a crucial role in the formation of Transitional Waters within the Pacific Tropical-Subtropical Convergence off Mexico. The importance of equatorward flows by the Tropical Branch of California Current in ventilating the Oxygen Minimum Zone waters in the Central Pacific off Mexico is emphasized.

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南下加利福尼亚州附近的加利福尼亚洋流系统

基于墨西哥南下加利福尼亚州附近两次航行（2010 年 6 月和 2012 年 5 月）的水文数据、2018 年世界海洋数据库、加州合作海洋渔业调查和 Investigaciones Mexicanas de la Corriente de California 邮轮计划的历史测量数据，以及卫星图像和来自全球再分析的数据，这项研究描述了南下加利福尼亚州附近的加利福尼亚洋流系统。加州洋流系统的特点是四个近地表洋流的相互作用。远离海岸，加州洋流在北太平洋副热带环流内流动，但不会到达墨西哥附近的太平洋热带-副热带辐合带。从十二月到六月，沿海出现一股被称为加州洋流热带支流的赤道气流。这种气流在三月至六月期间加强，与沿海上升流引起的质量通量密切相关。七月，加州洋流热带支流的一个新分支沿着南下加利福尼亚州海岸转向极地。这种水流通常被称为加州表面逆流，因为它的流动方向与加州海流相反。此外，还检测到加州潜流，影响 100 至 900 m 的水柱，最大流向极地流在 200 m 至 300 m 之间，流向地表逐渐减少。加州暗流全年持续存在于大陆坡上，在加州湾入口周围显示出显着的半年成分。南下加利福尼亚州附近的加利福尼亚洋流系统对于墨西哥附近太平洋热带-副热带辐合带内过渡水域的形成起着至关重要的作用。强调了加利福尼亚洋流热带支流向赤道流动对于墨西哥附近中太平洋最低氧区水域通风的重要性。