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首页> 外文期刊>Paleoceanography >Primary productivity response to heinrich events in the North Atlantic ocean and Norwegian sea
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Primary productivity response to heinrich events in the North Atlantic ocean and Norwegian sea

机译：对北大西洋和挪威海的海因里希事件的主要生产力反应

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The last glacial was punctuated by several massive ice sheet surges into the North Atlantic that impacted surface water hydrology especially where icebergs melted. However, the links between variations in surface water hydrology and surface water productivity during these Heinrich events (HEs) remain uncertain. To address this issue, diatoms and organic carbon were examined across Heinrich event 1 (HE 1) and Heinrich event 4 (HE 4) in seven sediment cores spanning 40 degrees N to 63 degrees N latitude. Our results show low diatom abundances during HEs, consistent with decreased surface water productivity. Diatom dilution by increased sediment flux was tested by normalizing diatom abundance to a constant Th-230 flux. Although the particle rain rate was enhanced during HEs, this does not explain the sharp drop in diatoms. During HE 4, surface productivity decreased at all latitudes examined, probably because of strong, year-round stratification. The same inferred changes occurred during HE 1 within the area of maximum iceberg melting. However, at northern latitudes (above 50 degrees N) the summer insolation increase of the glacial termination drove increased surface productivity during the whole period, including HE 1. Marine organic carbon, taken as independent proxy for export production, supports the diatom data. Trends shown by the productivity proxies evolve generally in parallel with the hydrographic proxies, with an increase in productivity when sea surface temperature increases.
机译：最后的冰川被北大西洋的几次大规模冰盖涌动所刺穿，这影响了地表水文水文学，特别是在冰山融化的地方。然而，在这些海因里希事件（HE）期间，地表水文水文变化与地表水生产率之间的联系仍然不确定。为了解决这个问题，在横跨海因里奇事件1（HE 1）和海因里希事件4（HE 4）的7个沉积物岩心中，研究了硅藻和有机碳，这些沉积物岩心的纬度为北纬40度至北纬63度。我们的结果表明，在高能状态下硅藻的丰度较低，这与地表水生产率的下降相一致。通过将硅藻丰度归一化为恒定的Th-230通量来测试通过增加沉积物通量来稀释硅藻。尽管在高中期间提高了粒子降雨率，但这不能解释硅藻的急剧下降。在HE 4期间，在所有纬度上的地表生产力都下降了，这可能是由于全年的强烈分层所致。在HE 1期间，最大冰山融化区域发生了相同的推断变化。但是，在北部纬度（北纬50度以上），冰川终止的夏季日照增加推动了包括HE 1在内的整个时期地表生产力的提高。海洋有机碳，作为出口生产的独立代表，支持硅藻数据。生产力代理所显示的趋势通常与水文代理并行发展，当海面温度升高时，生产力也会提高。

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