Global Climate Change Studies on Long and Short Time Scales

9314730莱德利全球气候变化长期和短期尺度研究气候变化在非常广泛的时间和空间尺度上，涉及气候系统所有组成部分的相互作用。气候系统的大多数建模研究往往侧重于特定的时间和空间尺度；然而，许多需要处理的跨学科气候问题要求对气候变化机制在更广泛的时间和空间尺度上的理解，而不是通常在一项研究中所处理的。在这项研究计划中，计划使用一个耦合的能量平衡气候-热力学海冰-大陆冰盖模式，在广泛的时间尺度上确定气候变化的重要机制，以便更好地了解这些机制如何影响气候系统。将讨论的具体问题包括：1)温室气体增加对冰冻圈和水文循环、地球-大气系统的影响，特别是对冰盖的形成有什么影响，产生这些变化的机制是什么，目前和预计温室气体的增加，以及在地质记录中观察到的温室气体在冰河时代时间尺度上的变化？具体而言，PI将讨论冰冻圈--包括海冰和大陆冰--如何对辐射强迫的变化及其对水文循环的影响作出反应的问题；进而冰冻圈的变化又如何影响气候。2)米兰科维奇太阳辐射变化如何影响水文循环和冰冻圈，以产生地质记录中所观察到的初始冰盖生长和大范围的冰川/间冰期循环。PI将具体审查水文循环在产生冰川/间冰期循环中的作用，并利用这一信息更好地了解太阳辐射季节循环的空间和时间变化在所有时间尺度上产生气候变化的作用。3)冰雪中的微粒对全球气候系统有什么影响，微粒的夹杂或沉积机制对气候系统的影响有多大？使用气候-热力耦合海冰-冰盖耦合能量平衡模式来解决这些问题特别有吸引力，因为它相对简单，同时保留了气候系统的许多大组成部分。这种类型的模型可以详细分析气候系统对各种扰动的反应，这将包括跟踪从初始扰动到所有包含的反馈过程的影响，直到最后的气候影响。通过对气候变化过程这类细节的了解，可以将我们在一组实验中学到的东西应用到发生在其他时间尺度上的气候变化问题上，扩大我们对气候系统及其变化方式的理解。***

9314730 Ledley Global Climate Change Studies on Long and Short Time Scales Climate changes on a very wide variety of time and space scales and involves the interaction of all of the components of the climate system. Most modeling studies of the climate system tend to focus on a particular range of time and space scales; however, many of the interdisciplinary climate questions that need to be addressed require an understanding of the mechanisms of climate change on a wider range of time and space scales than would normally be addressed in one study. In this research program the plan is to use a coupled energy balance climate-thermodynamic sea ice-continental ice sheet model to identify the important mechanisms of climate change on a wide range of time scales in order to gain a better understanding of how these mechanisms affect the climate system. The particular questions that will be addressed include: 1) What is the impact of increased greenhouse gases on the cryosphere and hydrologic cycle, of the Earth-atmosphere system, especially with respect to the initiation of ice sheet growth, and what are the mechanisms that produce those changes, for the present and projected increases in greenhouse gases, and for the variations in greenhouse gases on ice age time scales as observed in the geologic record? In particular the PI will address the question of how the cryosphere, both sea ice and continental ice, responds to the changes in radiative forcing and its impact on the hydrologic cycle; and in turn how the resulting changes in the cryosphere affect the climate. 2) How do Milankovitch solar radiation variations affect the hydrologic cycle, and the cryosphere to produce initial ice sheet growth and the large scale glacial/interglacial cycles as observed in the geological record. The PI will specifically examine the role of the hydrologic cycle in producing glacial/interglacial cycles and use this information to gain a better understanding of the role of spatial and temporal variations in the seasonal cycle of solar radiation on producing climate change on all time scales. 3) What is the impact of particulates in and on snow and ice on the global climate system, and how important is the mechanism of inclusion or deposition of the particulates in affecting the climate system? The use of the coupled energy balance climate-thermodynamic sea ice-ice sheet model to address these questions is particularly attractive because of its relative simplicity, while retaining many of the large components of the climate system. This type of model allows a detailed analysis of the response of the climate system to various perturbations, that will include following the effect from initial perturbation, through all of the included feedback processes, to the final climatic effect. Understanding the processes of climate change in this type of detail permits the application of what we learn in one set of experiments to questions of climate change that occur on other time scales, extending our understanding of the climate system and how it changes. ***