COLLABORATIVE RESEARCH: Complexity and Paleodynamics of Natural Sand Dune Fields

天然沙丘的结构复杂性和古动力学研究科库雷克奇-0106603沙丘呈现出一些在地球和其他行星（如火星）上看到的最有趣的图案。当风把沙粒吹走，使它们堆积成小土丘，最终演变成装饰日历和邮票的优美形状时，沙丘就形成了。风的特征，如风向和沙的供应，都以这样一种方式印在沙丘的图案上，只要仔细检查沙丘的图案，就可以说一些导致其形成的气候条件。随着时间的推移，风和沙的供应发生了变化，沙丘的格局也在慢慢变化，但变化的方式还没有完全描绘出来。存储在非洲、中东、亚洲、澳大利亚和北美的大沙丘中的过去数千年至数万年的气候信息可能为预测区域气候和景观对人类引起的全球气候变化的反应提供重要的理解。研究所的目标是开发一种从沙丘模式推断过去气候的方法，并将其应用于三个自然沙丘领域。为了实现这一目标，他们开发了跨越沙丘和沙丘场对气候变化作出反应的时间段范围的数值模型：（1）沙丘场总体特征的模型，包括沙丘之间的间距及其方向（数千年）;（2）沙丘顶部，其顶线的运动轨迹的模型（3）沙丘形态变化模型（数十年）。这些模型将用于调查加州东南部Algodones沙丘场、纳米比亚西部纳米比亚沙漠沙丘和毛里塔尼亚西部沙漠沙丘的发展。PI得出的解释有关过去的气候将通过尝试重新创建这三个沙丘领域的模式，在充满沙子的风洞中使用他们的气候推断进行测试。

BSTRACTCOMPLEXITY AND PALEODYNAMICS OF NATURAL SAND DUNE FIELDSGary KocurekEAR-0106603Fields of sand dunes present some of the most intriguing patterns seen on Earth and other planets, such as Mars. The dunes form when wind transports sand grains, causing them to pile up into small mounds that eventually evolve into the graceful shapes that adorn calendars and postage stamps. The characteristics of the wind, such as its direction and the supply of sand, are imprinted on the pattern of dunes in such a way that it is possible, just by carefully examining the dune pattern, to say something about the climatic conditions that lead to its creation. As winds and sand supply change through time, the pattern of dunes slowly changes as well in ways that are not yet fully delineated. The information about climate over the past thousands to tens of thousands of years stored in the great sand dune fields of Africa, the Middle East, Asia, Australia and North America might provide critical understanding in predicting the reaction of regional climates and landscapes to human-induced global climate change. PIs aim is to develop a methodology for inferring past climate from dune patterns and to apply it to three natural dune fields. To achieve this goal, they have developed numerical models that span the range of time periods over which dunes and dune fields can react to changes in climate: (1) a model for the overall characteristics of dune fields, including spacing between dunes and their orientation (thousands of years); (2) a model for the motion of the trace of the tops of dunes, their crestlines (hundreds of years); and (3) a model for the changes in shapes of dunes (tens of years). These models will be used to investigate the development of the Algodones dune field in southeastern California, the dunes of the Namibian desert in western Namibia, and the dunes of the deserts of western Mauritania. The interpretations PIs derive regarding past climate will be tested by attempting to recreate the patterns of these three dune fields using their climatic inferences in a wind tunnel filled with sand.