新元古代“雪球地球”模拟研究

A hypothesis of “snowball Earth” is a hotspot in the study of international paleoclimate. The simulation of snowball earth is significant for understanding modern climate and predicting future climate, while, the simulation and study using EMIC on which are very little in China.. This program will carry on simulations of snowball earth mainly from three aspects. We will study the climate characteristics of the snowball earth in the Neoproterozoic as well as the critical conditions (solar constant and carbon dioxide concentration in the atmosphere) of snowball earth initiation and deglaciation based on numerical simulation, statistical analysis and dynamic diagnose firstly. The probable cause of the climate change in the Neoproterozoic will also be illustrated in this part. Secondly we will compare and analyze the effects of different land cover and ocean heat transport on Neoproterozoic earth climate, the probable mechanism of which will be revealed by dynamic diagnose and simulation data analysis in this program. Finally, the effects of continental ice sheet on the initiation and deglaciation of snowball earth during Neoproterozoic are investigated in order to find their relationship. In this part we will discuss the importance of the continental ice sheet to earth climate. . The work in this respect has great instructive significance and actual value for the understanding of climate change, modern climate formation, natural geographical environment evolution, division and correlation of stratum, as well as the origin and detection of mineral resources. It will provide a new idea for the research on earth climate change. The work is also significant for better understanding the formation and evolution of ancient earth climate. In addition, to clarify the cause of typical icehouse during this period has some reference value to the current man-made greenhouse.

新元古代“雪球地球”研究，对于了解现代气候，预测未来气候具有重要意义。然而，目前国内关于新元古代“雪球地球”中等复杂程度地球系统模式数值模拟及其主要影响因素的研究工作还未涉及。本项目将通过数值模拟，结合统计分析和动力诊断，研究新元古代“雪球地球”气候特征以及“雪球地球”“产生”和“消融”时的太阳常数和大气二氧化碳浓度，揭示新元古代地球气候变化的可能原因；同时分析和比较地表覆盖和海洋热量输送对新元古代地球气候的影响，通过动力学诊断并结合模拟数据分析，揭示其影响的可能机制，最后探讨大陆冰盖对新元古代“雪球地球”“产生”和“消融”的影响，揭示其影响的可能机制。这方面工作的开展，将为研究地球气候发展变化提供一个新的思路，对于了解气候变迁、现代气候的形成、自然地理环境的演变、地层划分和对比、地壳演化研究以及矿产资源成因和探测等都有重要指导意义和现实价值。

新元古代“雪球地球”研究，对于了解现代气候形成，预测未来气候变化具有重要意义。然而，目前国内关于新元古代“雪球地球”中等复杂程度地球系统模式数值模拟及其主要影响因素的研究工作还很少。本项目通过数值模拟，结合统计分析和动力诊断，研究了新元古代“雪球地球”气候特征，研究发现在650Ma之前地球全球平均温度一直在零度以下，全球冰覆盖面积一直在增加，在650Ma时，全球平均温度达到零度以上，全球冰面积逐渐减小，这是由于在650Ma之前，在当时的太阳辐射和二氧化碳共同作用下，冰室效应强于温室效应，导致全球冰川化；同时分析和比较了地表覆盖对地球气候的影响，发现局地地表覆盖的变化不但造成局地气候的变化，还会引起全球气候变化，通过动力学诊断并结合模拟数据分析，揭示了其影响地球气候的可能机制；最后研究了海洋热量输送对地球气候的影响，研究发现在新元古代和现代两种不同海陆分布下，海洋热量输送发生了显著变化，进而导致全球气候的变化。在此基础上，进一步探讨了海洋热量输送和温盐环流流函数对地球气候变化的响应，揭示了其响应的可能机制。这方面工作的开展，将为研究地球气候发展变化提供一个新的思路，对于了解气候变迁、现代气候的形成、自然地理环境的演变、地层划分和对比、地壳演化研究以及矿产资源成因和探测等都有重要指导意义和现实价值。