Climate Forcing, Ocean Circulation, and the Geologic Record of Global Change Across the Cenomanian/Turonian Boundary, Western Interior Seaway of North America

地层沉积在全球温暖，平静，白垩纪 这一时期保存了一项独特的自然实验的记录， 将帮助我们更好地理解 一体化地球系统 西部的地层记录 内部白垩纪航道（WIKS）提供了无与伦比的 学习的机会，因为大量的可用性 可以进行综合和分析的成熟数据集。 使用WIKS 作为一个工作“实验室”，我们建议：（1）了解全球 气候系统及其变率 温暖;（2）验证气候模型的条件， 与今天不同;（3）确定海洋学， 生物和化学反应的WIKS跨越C/T 全球和区域强迫因子的边界;（4） 更好地定义这些海浪响应与 西部内陆盆地的地质记录。 在这项研究中， 受不同WIKS数据集约束的模型模拟将 进行了三次切片，代表不同阶段的 一个主要的二级海平面旋回（Greenhorn cyclothem）。 为 每个时间片我们将：（1）确定全球古地理， 古地形，海平面和大气pCO 2 文献;（2）进行全球基线数值实验 气候使用NCAR社区气候模型（CCM）;（3）执行 CCM对海平面变化的一系列敏感性实验，低 与高地形、可变轨道参数和可变 pCO 2;（4）研究WIKS对CCM变化的敏感性 利用每日风应力和蒸发量减去降水量 来驱动一个三维的湍流， （5）探讨了这些因素对海岸带海洋模型的影响 循环变化可能对有机碳生产产生的影响， 碳和氧同位素的化学示踪剂， 循环模型和发展中的营养物，氧气， 和盐度;和（6）测试这些预测，通过组装 岩相图、底栖生物相/氧梯度图和 推断的温度、古盐度和有机碳 分布

Strata deposited during the globally warm, equable, Cretaceous period preserve the record of a unique natural experiment which will help us better understand the dynamical behavior of the integrated earth system. The stratigraphic record of the Western Interior Cretaceous Seaway (WIKS) provides an unparalleled opportunity for study because of the availability of substantial data sets that are ripe for synthesis and analysis. Using the WIKS as a working "laboratory" we propose to: (1) understand the global climate system and its variability during a period of extreme warmth; (2) validate climate models for conditions substantially different from the present day; (3) determine the oceanographic, biological, and chemical responses of the WIKS across the C/T boundary to both global and regional forcing factors; and (4) better define the links between these seaway responses and the geologic record of the Western Interior Basin. In this study a series of hierarchical atmospheric and ocean model simulations constrained by the diverse WIKS dataset will be performed for three times slices representing different stages of a major second order sea level cycle (Greenhorn cyclothem). For each time slice we will: (1) determine the global paleogeography, paleotopography, sea level, and atmospheric pCO2 from the literature; (2) perform baseline numerical experiments of global climate using the NCAR Community Climate Model (CCM); (3) perform a series of CCM sensitivity experiments to sealevel changes, low versus high topography, variable orbital parameters, and variable pCO2; (4) investigate the sensitivity of the WIKS to CCM variation by using daily wind stresses and evaporation minus precipitation from the CCM runs to drive a three-dimensional, turbulent flow, coastal ocean model; (5) investigate the influence these circulation changes might have on organic carbon production, and carbon and oxygen isotopes by following chemical tracers in the circulation model and developing box models of nutrients, oxygen, and salinity; and (6) test these predictions by assembling lithofacies maps, benthic biofacies/oxygen gradient maps, and maps of inferred temperature, paleosalinity and organic carbon distribution.