期刊
PALEOCEANOGRAPHY
卷 31, 期 9, 页码 1270-1282出版社
AMER GEOPHYSICAL UNION
DOI: 10.1002/2016PA002958
关键词
paleoclimate; carbon dioxide; global climate; global ice volume; sea level; benthic oxygen isotopes
资金
- Netherlands Organisation of Scientific Research NWO-ALW grant
- European Union's Horizon research and innovation program under the Marie Sklodowska-Curie [660814]
- Marie Curie Actions (MSCA) [660814] Funding Source: Marie Curie Actions (MSCA)
Knowledge on climate change during the Cenozoic largely stems from benthic O-18 records, which document combined effects of deep-sea temperature and ice volume. Information on CO2 is expanding but remains uncertain and intermittent. Attempts to reconcile O-18, sea level, and CO2 by studying proxy data suffer from paucity of data and apparent inconsistencies among different records. One outstanding issue is the difference suggested by proxy CO2 data between the Eocene-Oligocene boundary (EOT) and the Middle-Miocene Climatic Optimum (MMCO), while similar levels of O-18 are shown during these times. This conundrum implies changing relations between O-18, CO2, and temperature over time. Here we use a coupled climate-ice sheet model, forced by two different benthic O-18 records, to obtain continuous and mutually consistent records of O-18, CO2, temperature, and sea level over the period 38 to 10Myr ago. We show that the different CO2 levels between the EOT and MMCO can be explained neither by the standard configuration of our model nor by altering the uncertain ablation parametrization on the East Antarctic Ice Sheet. However, we offer an explanation for the MMCO-EOT conundrum by considering erosion and/or tectonic movement of Antarctica, letting the topography evolve over time. A decreasing height of the Antarctic continent leads to higher surface temperatures, reducing the CO2 needed to maintain the same ice volume. This also leads to an increasing contribution of ice volume to the O-18 signal. This result is, however, dependent on how the topographic changes are implemented in our ice sheet model.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据