Response of biological productivity to North Atlantic marine front migration during the Holocene
Response of biological productivity to North Atlantic marine front migration during the Holocene
复制标题
DOI：
10.5194/cp-17-379-2021
复制
发表时间：
2021-02-08
影响因子：
4.3
通讯作者：
Sepulveda, Julio
中科院分区：
文献类型：
--
作者：
Harning, David J.;Jennings, Anne E.;Sepulveda, Julio
海洋锋划定了不同水团之间的边界，并通过营养物质的平流，成为区域生产力和生物多样性的重要促进因素。随着现代气候的不断变化，锋面带的迁移是显而易见的，但在仪器记录之前缺乏关于其状态的信息阻碍了未来的预测。在这里，我们结合联合收割机的数据，从脂质生物标志物（古生类异戊二烯甘油二联植烷甘油四醚和藻类高度分支类异戊二烯）与南极和底栖有孔虫组合，详细的生物反应的海洋北极和极锋迁移的北冰岛大陆架（NIS）在过去的8 kyr。这种多代理的方法使我们能够量化的热结构有关的北极和极锋迁移和测试如何影响当地远洋生产力的相应变化。我们的数据表明，在大西洋水的影响，北极锋及其相关的高远洋生产力迁移东南向的NIS类似6.1万年的间隔。在随后的区域冷却趋势，极地水从东格陵兰电流和相关的极锋传播到NIS的类似的3.8万年，大大减少了当地的藻类生产力通过小冰期。在上个世纪，北极和极地锋向北移动，回到了相对于新独立国家的当前位置，并帮助刺激了生产力，部分支持了冰岛的经济。我们从NIS的全新世记录提供了类似的当前锋面配置和生产力，它支持可能会随着全球气温的持续上升而发生变化。
Marine fronts delineate the boundary between distinct water masses and, through the advection of nutrients, are important facilitators of regional productivity and biodiversity. As the modern climate continues to change, the migration of frontal zones is evident, but a lack of information about their status prior to instrumental records hinders future projections. Here, we combine data from lipid biomarkers (archaeal isoprenoid glycerol dibiphytanyl glycerol tetraethers and algal highly branched isoprenoids) with planktic and benthic foraminifera assemblages to detail the biological response of the marine Arctic and polar front migrations on the North Iceland Shelf (NIS) over the last 8 kyr. This multi-proxy approach enables us to quantify the thermal structure relating to Arctic and polar front migration and test how this influences the corresponding changes in local pelagic productivity. Our data show that following an interval of Atlantic water influence, the Arctic front and its associated high pelagic productivity migrated southeastward to the NIS by similar to 6.1 ka. Following a subsequent trend in regional cooling, Polar Water from the East Greenland Current and the associated polar front spread onto the NIS by similar to 3.8 ka, greatly diminishing local algal productivity through the Little Ice Age. Within the last century, the Arctic and polar fronts have moved northward back to their current positions relative to the NIS and helped stimulate the productivity that partially supports Iceland's economy. Our Holocene records from the NIS provide analogues for how the current frontal configuration and the productivity that it supports may change as global temperatures continue to rise.