Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years
Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years
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DOI：
10.1016/j.epsl.2019.06.028
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发表时间：
2019-08
影响因子：
5.3
通讯作者：
Savannah Worne;S. Kender;G. Swann;M. Leng;A. Ravelo
中科院分区：
文献类型：
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作者：
Savannah Worne;S. Kender;G. Swann;M. Leng;A. Ravelo
高纬度深水上涌有可能通过生物泵和海洋-大气二氧化碳交换来控制冰川时间尺度上的全球气候。然而，目前缺乏连续的长期营养上升记录来评估这一机制。在这里，我们提供了过去850KYR白令海营养物质上升流和冰川北太平洋中间水(GNPIW)形成的地球化学替代记录，这表明冰期的特征是营养物质上升流减少，同时全球大气CO2和温度也降低。我们认为，白令海海冰的冰川扩张，以及低营养物质GNPIW的同时扩张，抑制了亚北极太平洋的垂直混合和营养物质供应。我们的发现支持高纬度海冰和由此产生的中间水的形成、调制的深水上升流和海洋-大气CO2在冰川-间冰期时间尺度上的交换的观点。
High latitude deep water upwelling has the potential to control global climate over glacial timescales through the biological pump and ocean-atmosphere CO2exchange. However, there is currently a lack of continuous long nutrient upwelling records with which to assess this mechanism. Here we present geochemical proxy records for nutrient upwelling and glacial North Pacific Intermediate Water (GNPIW) formation in the Bering Sea over the past 850 kyr, which demonstrates that glacial periods were characterised by reduced nutrient upwelling, when global atmospheric CO2and temperature were also lowered. We suggest that glacial expansion of sea ice in the Bering Sea, and the simultaneous expansion of low nutrient GNPIW, inhibited vertical mixing and nutrient supply across the subarctic Pacific Ocean. Our findings lend support to the suggestion that high latitude sea ice and the resultant intermediate water formation, modulated deep water upwelling and ocean-atmosphere CO2exchange on glacial-interglacial timescales.