National Centre for Antarctic & Ocean Research, Vasco-da-Gama, Goa, India.
Physical Research Laboratory, Navrangpura, Ahmedabad, India.
PLoS One. 2018 Aug 15;13(8):e0201456. doi: 10.1371/journal.pone.0201456. eCollection 2018.
Arctic fjords feature among some of the most climate-sensitive regions on the planet. The site of this study-Kongsfjorden-is one such fjord in which sedimentation and sediment geochemistry reflect climate-mediated changes in glacial melt and marine primary productivity. Here, we have shown that the fjord is particularly sensitive to the changing melt dynamics of the surrounding glaciers which are a direct consequence of warming/cooling in the region and is reflected in the productivity at the fjord. Warming increases meltwater influx into the fjord leading to enhanced turbidity which results in lower productivity. A multi-proxy study (sedimentary organic matter content, carbon and nitrogen isotope ratios, and microfossil abundance) using a 21 cm long sediment core from the Kongsfjorden helped us reconstruct warming driven melt-dynamics history for the past two centuries. Proxy data show a general decreasing trend in productivity along with a few excursions over the last two centuries. Warming driven glacial-melt dynamics appears to be the dominant control on productivity throughout the span of the core.
北极峡湾是地球上对气候最敏感的地区之一。本研究的地点——康斯峡湾就是这样一个峡湾，其沉积物和沉积物地球化学反映了冰川融化和海洋初级生产力变化所介导的气候变化。在这里，我们已经表明，峡湾对周围冰川融化动态特别敏感，这是该地区变暖/冷却的直接后果，并反映在峡湾的生产力上。变暖会增加流入峡湾的融水量，导致浊度增加，从而降低生产力。一项利用来自康斯峡湾的 21 厘米长沉积物岩芯的多指标研究（沉积物有机物质含量、碳和氮同位素比值以及微体化石丰度）帮助我们重建了过去两个世纪中受变暖驱动的融冰动力学历史。代理数据显示，在过去的两个世纪里，生产力总体呈下降趋势，但也有几次波动。在整个岩芯范围内，变暖驱动的冰川融化动力学似乎是生产力的主要控制因素。
