Comparative carbon cycle dynamics of the present and last interglacial
Comparative carbon cycle dynamics of the present and last interglacial
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DOI：
10.1016/j.quascirev.2016.01.028
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发表时间：
2016-04-01
影响因子：
4
通讯作者：
Jensen, Dorthe Dahl
中科院分区：
文献类型：
--
作者：
Brovkin, Victor;Bruecher, Tim;Jensen, Dorthe Dahl
在南极冰芯记录的冰川循环期间，温度和二氧化碳的变化是紧密耦合的。然而，这种关系并不适用于间冰期。尽管气候在最后一次（Eemian）和现在（全新世）的间冰期结束时变冷，但在Eemian期间CO2保持稳定，而在全新世则上升。我们确定和审查了12个地球化学机制的陆地（植被动态和CO2施肥、土地利用、野火、泥炭积累、永冻层碳变化、陆上火山出气）和海洋起源（海洋表面温度的变化、碳酸盐对冰川消退和陆地生物圈再生的补偿、浅水碳酸盐沉积、软组织泵的变化和甲烷水合物），这可能有助于间冰期期间的二氧化碳动态，但仍然没有很好地量化。我们使用三个地球系统模型（ESM）的中间复杂性，比较选定的机制间冰期CO2和三角洲（CO2）-C-13变化的影响，侧重于那些具有实质性的潜在影响：即碳酸盐沉积在浅水沃茨，泥炭生长，（在全新世的情况下）人类土地利用。一组特定的碳循环强迫可以定性地解释从8 kaBP到工业革命前的大气CO2动力学。然而，当应用到Eemian边界条件从126至115万年BP，相同的一组强迫导致不同意与观察到的CO2变化的方向后，122万年BP。未能模拟晚Eemian CO2动力学可能是一个结果，如规定的CaCO 3积累和/或模拟陆地碳的表面冷却在间冰期结束时的不正确的反应强加的强迫。这些实验还表明，间冰期CO2动态的关键自然过程-浅水CaCO 3积累，泥炭和永久冻土碳动态在目前的ESM中没有得到很好的代表。这些长期的碳循环成分的全球尺度建模仅在过去十年中才开始，这些机制的参数化的不确定性是间冰期CO2动力学成功建模的主要限制。(C)2016年6月，作者。由爱思唯尔有限公司出版。这是一篇开放获取的文章，使用CC BY许可证（http：//creativecommons.org/licenses/by/4.0/）。
Changes in temperature and carbon dioxide during glacial cycles recorded in Antarctic ice cores are tightly coupled. However, this relationship does not hold for interglacials. While climate cooled towards the end of both the last (Eemian) and present (Holocene) interglacials, CO2 remained stable during the Eemian while rising in the Holocene. We identify and review twelve biogeochemical mechanisms of terrestrial (vegetation dynamics and CO2 fertilization, land use, wildfire, accumulation of peat, changes in permafrost carbon, subaerial volcanic outgassing) and marine origin (changes in sea surface temperature, carbonate compensation to deglaciation and terrestrial biosphere regrowth, shallow-water carbonate sedimentation, changes in the soft tissue pump, and methane hydrates), which potentially may have contributed to the CO2 dynamics during interglacials but which remain not well quantified. We use three Earth System Models (ESMs) of intermediate complexity to compare effects of selected mechanisms on the interglacial CO2 and delta(CO2)-C-13 changes, focusing on those with substantial potential impacts: namely carbonate sedimentation in shallow waters, peat growth, and (in the case of the Holocene) human land use. A set of specified carbon cycle forcings could qualitatively explain atmospheric CO2 dynamics from 8 ka BP to the pre-industrial. However, when applied to Eemian boundary conditions from 126 to 115 ka BP, the same set of forcings led to disagreement with the observed direction of CO2 changes after 122 ka BP. This failure to simulate late-Eemian CO2 dynamics could be a result of the imposed forcings such as prescribed CaCO3 accumulation and/or an incorrect response of simulated terrestrial carbon to the surface cooling at the end of the interglacial. These experiments also reveal that key natural processes of interglacial CO2 dynamics - shallow water CaCO3 accumulation, peat and permafrost carbon dynamics are not well represented in the current ESMs. Global-scale modeling of these long-term carbon cycle components started only in the last decade, and uncertainty in parameterization of these mechanisms is a main limitation in the successful modeling of interglacial CO2 dynamics. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).