Gouveia Mainara Biazati, Peneva Elisaveta, Gancheva Irina, Stanev Emil V
Meteorology and Geophysics Department, Faculty of Physics, Sofia University "St. Kliment Ohridski", 1164, Sofia, Bulgaria.
Institute of Coastal Systems - Analysis and Modeling, Helmholtz-Zentrum Hereon, 21502, Geesthacht, Germany.
Sci Rep. 2025 Jun 6;15(1):20006. doi: 10.1038/s41598-025-00432-5.
The quasi-steady Lagrangian transport patterns in the Black Sea are quantified and identified from climatological Lagrangian Coherent Structures. Wind velocity and Earth observation data have been incorporated to illustrate the potential applications of these results. The persistent squeezelines show that the high aggregation of passive tracers in the coastal region is a consequence of the complex coastal configuration of the Black Sea. The continental shelf is characterized by high stirring and mixing activities. The persistent and recurrent pathway patterns on the northwestern shelf are responsible for attracting nearby water parcels and passive tracers and conducting them towards the southern platform and offshore. Along the Rim Current, fifteen regions were identified as chevrons, indicating that they are jet-like structures. The jet-like structures and the northwestern shelf play an essential role in facilitating cross-shelf transport of material to neighboring coastal regions and offshore areas. Four transport barriers were identified by the climatological Lagrangian Coherent Structures as being both efficient and critical to the Lagrangian transport, and to the protection of coastal regions. One of these barriers is also identified as the Lagrangian Front. The Rim Current accounts for 44% of the Black Sea basin's climatological attraction strength. The Rim Current and the basin-wide climatological attraction strength show seasonal variations, with the highest values observed in winter. The distribution of persistent and recurrent mesoscale activity is also analyzed. The prevailing tendency among eddies identified is an anticyclonic orientation, typified by elevated levels of stirring and mixing. It is evident that an increase in wind speed over the basin results in a corresponding rise in the climatological attraction force exerted by anticyclonic eddies. This, in turn, leads to an enhancement in the process of stirring, mixing, and aggregation of nearby water parcels and passive tracers. However, it has been demonstrated that the presence of eddies is reduced in proportion to the velocity of the wind, particularly in the case of cyclonic eddies. The study offers valuable insights into the complex transport dynamics of the Black Sea ecosystem, with potential implications for environmental management and conservation efforts.
从气候学拉格朗日相干结构中量化并识别了黑海的准稳态拉格朗日输运模式。已纳入风速和地球观测数据以说明这些结果的潜在应用。持续存在的挤压线表明，沿海地区被动示踪剂的高度聚集是黑海复杂海岸地形的结果。大陆架的特点是具有高度的搅动和混合活动。西北大陆架上持续且反复出现的路径模式负责吸引附近的水体和被动示踪剂，并将它们导向南部平台和近海。沿着边缘流，有15个区域被识别为V形，表明它们是类似急流的结构。类似急流的结构和西北大陆架在促进物质跨陆架向邻近沿海地区和近海区域的输运方面发挥着重要作用。气候学拉格朗日相干结构识别出四个对拉格朗日输运以及对沿海地区保护既有效又关键的输运屏障。其中一个屏障也被识别为拉格朗日锋。边缘流占黑海盆地气候学吸引强度的44%。边缘流和全盆地气候学吸引强度呈现季节性变化，冬季观测到的值最高。还分析了持续且反复出现的中尺度活动的分布。所识别出的涡旋的主要趋势是反气旋方向，其特征是搅动和混合水平升高。显然，盆地风速的增加会导致反气旋涡旋施加的气候学吸引力相应增加。这反过来又导致附近水体和被动示踪剂的搅动、混合和聚集过程增强。然而，已经证明涡旋的存在与风速成比例减少，特别是在气旋涡旋的情况下。该研究为黑海生态系统复杂的输运动力学提供了有价值的见解，对环境管理和保护工作具有潜在影响。
