Carbonate Compensation Dynamics in the Past and Future

我的研究计划正在经历一个根本性的方向转变。 从三十年的沉积物建模过程中，我决定专注于影响我们社会的大规模海洋相关问题。 具体来说，我选择从预测海洋酸化开始。 酸度的增加正在并将对海洋生物产生深远的、主要是负面的影响。 这种酸性的来源是人为产生的二氧化碳在大气中的积累及其随后被海洋吸收。 在海洋中有一个自然的中和过程，称为补偿，它涉及以前沉积在海底的碳酸钙的溶解。 但是，中和与酸的输入速率不同步。 我们需要更好和更充分地了解中和的机制及其发生的时间尺度。 我目前的研究计划的目标是调查和理解这些机制，包括它们的时间尺度和它们对地球化学环境的影响。 目前对中和率的预测来自于极其难以解决的复杂海洋模型。 作为建立我的新研究计划的第一步，我成功地制定了一个非常简单的CO2中和模型，该模型似乎与复杂模型的预测一样可靠。 在接下来的5年里，我希望通过将我的新模型应用于地球历史上过去的酸化事件来测试它的实用性，力量和弹性。 一个这样的事件发生在5580万年前（PETM）。 关于当时的海洋环境条件，已经收集了大量的数据（通过所谓的古海洋学代理）。 与一位博士后研究员合作，我将把我的模型输出与这些数据进行比较，以测试我的模型的后报能力。 成功将意味着将存在一个简单而强大的工具来模拟海洋的未来。

My research program is undergoing a radical change of direction. From three decades of modelling processes in sediments, I have decided to focus on large scale ocean-related problems that impact our society. Specifically, I have chosen to start with predicting acidification of the oceans. The increased acidity is having and will have profound, largely negative, effects on the biology of the Oceans. The source of this acidity is the build-up of man-produced CO2 in the atmosphere and its subsequent adsorption by the Oceans. There is a natural neutralization process acting in the Oceans, called compensation, which involves dissolution of previously deposited calcium carbonate on the seafloor. However, the neutralization is out of synchronization with the input rate of acid. We need to understand better and more fully the mechanics of the neutralization and the time scales on which it will occur. It is the goal of my current research program to investigate and comprehend these mechanisms, including their time scales and their consequences to the earth's chemical environment. The prediction of the rate of neutralization currently comes from complex models of the oceans that are extremely difficult to solve. As a first step in building my new research program, I have succeeded in formulating a very simple model of CO2 neutralization, which appears to give predictions as robust as those from the complex models. Over the next 5 years I wish to test the utility, power and resilience of my new model by applying it to past acidification events in the Earth's history. One such event occurred 55.8 M years ago (the PETM). A great deal of data has been collected about oceanic environmental conditions at that time (via so-called paleoceanographic proxies). Working with a post-doctoral fellow(s) I will compare my model output with those data to test the hindcasting ability of my model. Success would mean that a simple and powerful tool would exist to model the Ocean's future.