Holocene climate dynamics and biogeochemical cycles in the Mediterranean Sea (HOBIMED)

我们建议研究从退冰期和全新世气候变化到地中海生物地球化学循环变化的机制。我们集中在这个盆地，因为它是一个半封闭的海洋盆地，在物理环流状况下对水文平衡的变化有非常大的反应。这片海洋的生物地球化学过程和海洋生态系统过去的变异性以北半球日照最大时出现的富含有机腐蚀物的形式被记录下来。为了了解地中海对高、低纬气候强迫的敏感性，并测量对预期的全球变化的响应范围，我们将在全新世最后一次冰川消融和气候极端时期对地中海进行模拟，包括过渡到腐泥S1，腐泥形成中断约8.2 KYR BP，以及全新世气候最佳时期的重新通风。我们的双重概念将通过使用地中海东部现有的和新的代理数据对全球和区域地球系统模型实验进行验证来实现。这些实验的目的是了解和量化在地中海东部产生停滞和缺氧深水状态所涉及的不同强迫机制和时间尺度的相对作用。

We propose to study the mechanisms leading from deglacial and Holocene climate change to changed biogeochemical cycling in the Mediterranean Sea. We concentrate on this basin because it is a semi-enclosed ocean basin with very large amplitude reactions in the physical circulation regime to variations in the hydrological balance. The past variability of biogeochemical processes and marine ecosystems of this ocean is documented in the form of organic-rich sapropels that occurred at northern hemisphere insolation maxima. In order to understand the sensitivity of the Mediterranean Sea to high- and low-latitude climate forcing and to gauge the range of response to expected global change, we will model the Mediterranean Sea at times of the last deglaciation and climate extremes in the Holocene, including the transition into sapropel S1, the interruption of sapropel formation around 8.2 kyr BP, and reventilation during the Holocene Climate Optimum. Our Dual+ concept will be realized by the validation of global and regional Earth system model experiments with available and new proxy data from the eastern Mediterranean Sea. The aim of these experiments is to understand and quantify the relative role of the different forcing mechanisms and time scales involved in generating a state with stagnant and anoxic deepwater in the eastern Mediterranean Sea.