The history of a cluster of large icebergs on leaving the Weddell Sea pack ice and their impact on the ocean
The history of a cluster of large icebergs on leaving the Weddell Sea pack ice and their impact on the ocean
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DOI：
10.1017/s0954102022000517
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发表时间：
2023-04
影响因子：
1.6
通讯作者：
G. Bigg;R. Marsh
中科院分区：
文献类型：
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作者：
G. Bigg;R. Marsh
摘要从2014年3月开始，追踪了南极半岛尖端附近威德尔海海冰中三座非常大的冰山的生活史和海洋影响。尽管这三座冰山最初很接近，但它们在南大西洋上的轨迹非常不同，直到一年后最终破裂并融化。最大的巨型冰山B17 a在两个不同的岛屿附近停留了很长时间。通过对冰山尺寸的影响，以及融水对当地盐度和初级生产力的海洋影响，研究了三重态的逐渐融化。据发现，一般有一个显着的局部表面和混合层淡化的十分之几的实际盐度单位，高达几百公里远的10-20公里大小的冰山。相比之下，叶绿素的影响是高度随时间变化的，虽然它往往是在夏季较大。这些大冰山直到生命的尽头才破碎。我们还表明，建模的轨迹个别非常大的冰山可以合理的长达2个星期，如果冰山和当地的海洋和大气强迫的特点是众所周知的。
Abstract The life history and oceanic impact of three very large icebergs that escaped together from the Weddell Sea sea ice, near the tip of the Antarctic Peninsula, are traced from March 2014. Despite the initial proximity of these three icebergs, they followed very different trajectories across the South Atlantic until their eventual break-up and melting 1 year later. The largest, giant iceberg, B17a, spent extensive periods grounded near two different islands. The triplet's gradual melting is examined through the impact on the icebergs' dimensions, but also the meltwater's oceanic influence on the local salinity and primary productivity. It is found that there was generally a significant local surface and mixed-layer freshening of a few tenths of a practical salinity unit, up to several hundred kilometres away from the 10–20 km-sized icebergs. In contrast, the chlorophyll impact was highly temporally variable, although it tended to be larger in the summer. Break-up of these large icebergs did not occur until near the end of their life. We also show that modelling the trajectories of individual very large icebergs can be reasonable for up to 2 weeks if the characteristics of the iceberg and the local ocean and atmospheric forcing are well known.