REU: History of Southern Hemisphere Atmospheric Circulation:The Indian Ocean Record

该项目将在东印度洋的ODP Leg 121钻井点建立整个新生代风成沉积记录。这一记录将在构造时间尺度上揭示南半球大气环流强度和大陆（主要是澳大利亚）干旱模式的历史。此外，这些数据将把整个白垩纪晚期到最近的风成期记录与海洋和冰冻圈的历史联系起来，这些记录是基于同位素和其他从同一岩心（有时是同一样品）确定的代理指标。有几个具体的问题或事件需要调查。第一个是白垩纪-第三纪界线上大气环流变化的性质。其次，描绘北半球在古新世-始新世边界发生的重要大气环流变化的南半球记录。第三，考察与始新世晚期-渐新世早期极地变冷和南极冰量变化相关的南半球大气环流的显著变化。在这方面，风强度是行星温度梯度的另一个指示，这一事实意味着这些数据将进一步限制冰量与温度的讨论。过去6000万年的古气候变化对大气的影响环流可以从深海沉积物中风吹颗粒的变化模式来确定。该项目将利用印度洋岩心中的风成物质来推断可能与气候变化有关的风模式的变化。由于大气对气候非常敏感，这些古环流结果将提供南半球古气候变化的监测。这一信息对于模拟研究印度洋对南极冰川的响应、青藏高原的隆升和北半球冰川的影响将非常重要。

This project will construct whole-Cenozoic record of eolian deposition from ODP Leg 121 drillsites in the eastern Indian Ocean. That record will reveal the history, on tectonic timescales, of Southern Hemisphere atmospheric circulation intensity and of patterns of continental (largely Australian) aridity. Further the data will link the entire late Cretaceous to recent eolian record to the history of the ocean and cryosphere based on isotopic and other proxy indicators determined from the same core, and sometimes the same samples. There are several specific questions or events to be investigated. The first of these is the nature of any changes in atmospheric circulation across the Cretaceous-Tertiary boundary. Secondly, to delineate the Southern Hemisphere record of the important change in atmospheric circulation that occurs in the Northern Hemisphere at the Paleocene-Eocene boundary. Third, examine significant changes in Southern Hemisphere atmospheric circulation that occur in conjunction with the latest Eocene - early Oligocene polar cooling and changes in Antarctic ice volume. In this regard the fact that wind intensity is another indication of the planetary temperature gradient means that the data will place further constraints on the ice-volume vs. temperature discussions. %%% The effects of paleoclimatic changes during the last 60 million years on atmospheric circulation may be determined from changing patterns of wind-blown particles in deep-sea sediments. This project will utilize the eolian material in drill cores from the Indian Ocean to infer shifting wind patterns that may be linked to climate changes. Because the atmosphere is very sensitive to climate, these paleocirculation results will provide a monitor of paleoclimatic changes in the Southern Hemisphere. This information will be very important in modelling studies of the Indian Ocean response to Antarctic glaciation, uplift of the Tibetan Plateau, and the effect of the Northern hemisphere glaciation.