Collaborative Research: Calibrating Mid-Miocene Greenhouse Climate and Ecology in a Key High Southern Latitude Locale

作者：Matthew J. Kohn，博伊西州立大学，Richard Kay，杜克大学，Caroline Stromberg，华盛顿大学中中新世气候最佳期（MMCO； 1450 - 1700万年前，Ma）标志着地球上一个异常温暖的时期。这是历史上最后一次大气二氧化碳含量（pCO2）达到预期在下个世纪的高水平。因此，MMCO是我们预测未来温室条件的最佳模拟。拟议的研究将通过表征地球的气候和生态来填补MMCO陆地地区分布的主要空白。美国最南端？巴塔哥尼亚海岸的圣克鲁斯组（51°S）。以往的工作和模式在年平均温度（MAT）、年平均降水量（MAP）和降水的季节性方面存在差异。我们将在17.45 Ma （MMCO峰值前）和16.85 Ma （MMCO峰值）两个特定时期对MAT、MAP和植被的古生态和古气候假设进行评估。稳定的同位素组成将用于推断干旱和季节性。植物岩（植物硅颗粒）将区分植物群落。牙齿磨损和动物群将限制栖息地和气候。我们的研究还将相互比较陆地环境下推断古生态和古气候的各种方法，这对全球陆地气候的相互比较具有广泛的意义。研究成果的传播和分享将遵循NSF13-1的指导方针。伯克博物馆（每年约有20,000名K-12学生参观，总计约75,000人）将举办一个关于生物对气候变化的反应的新展览，以及相关的网页（“探索你的世界”，“伯克博客”条目）和社交媒体（如Facebook）。将支持几名研究生，并在美国和阿根廷研究人员之间建立新的古气候-古生态学-古生物学网络。

Collaborative Research: Calibrating mid-Miocene greenhouse climate and e4cology in a key high southern latitude locale By Matthew J. Kohn, Boise State University, EAR-1349749 Richard Kay, Duke University, EAR-1349741 Caroline Stromberg, University of Washington, EAR-1349530 The mid-Miocene Climatic Optimum (MMCO; 14.5-17.0 million years ago, Ma) marks an unusually warm period in Earth?s history and is the last time that atmospheric CO2 content (pCO2) plausibly reached levels as high as anticipated in the next century. Thus the MMCO serves as our best analogue for predicting future greenhouse conditions. The proposed research will fill a major gap in the distribution of MMCO terrestrial localities by characterizing climates and ecologies of Earth?s southernmost site ? the Santa Cruz Formation of coastal Patagonia (51 °S). Previous work and models disagree in terms of mean annual temperature (MAT), mean annual precipitation (MAP) and the seasonality of precipitation. We will evaluate paleoecological and paleoclimate hypotheses regarding MAT, MAP and vegetation at two specific times: 17.45 (pre-peak MMCO) and 16.85 Ma (peak MMCO). Stable isotope compositions will be used to infer aridity and seasonality. Phytoliths (plant silica particles) will distinguish plant communities. Tooth wear and faunas will constrain habitat and climate. Our research will also intercompare diverse methods of inferring paleoecology and paleoclimate in terrestrial settings with broad implications for terrestrial climate intercomparisons worldwide. Dissemination and sharing of research results will comply with guidelines expressed in NSF13-1. A new exhibit will be constructed at the Burke Museum (annual visitation of c. 20,000 K-12 students, c. 75,000 total) on biotic responses to climate change, as well as accompanying web pages ("Explore Your World," "Burke Blog" entries) and social media (e.g., Facebook). Several graduate students will be supported, and new paleoclimate-paleoecology-paleontology networks among US and Argentine researchers will be initiated.