Heinrich-Scale Events in Western North America and the Northeastern Pacific? Testing Possible Mechanisms

9615822惠特洛克奖支持一项合作研究工作，以测试北美西部和太平洋东北部现已认识到的千年尺度气候波动的发生假说。加利福尼亚州和俄勒冈州近海海洋沉积物的初步数据，太平洋西北部湖泊的花粉记录，以及北美西部的冰川记录显示，气候事件似乎与北大西洋的海因里希事件有关。这项研究将检验两个假设：1)起源于北大西洋的气候事件通过温盐环流传递到北太平洋和北美西部，及其对表层海洋特征和大气环流的影响；2)北大西洋、北美和东北太平洋的气候共同取决于劳伦蒂德冰盖的高程及其对大气环流的影响。通过分析太平洋东北部和北美西部一系列地点的古气候记录，这些假设将受到限制。这项研究的重点将包括：对海洋上升流和近地表平流的限制，深海性质和陆地植被，并将这些数据与模型输出进行比较。将来自陆地和海洋的记录与严格限制的年代学以及海洋岩心中的花粉和陆源沉积物的地层联系联系起来，将是一项重大的进步。

9615822 Whitlock This award supports a collaborative research effort to test hypotheses regarding the occurrence of millennial-scale climate fluctuations now recognized in western North America and the northeastern Pacific Ocean. Preliminary data from marine sediments off California and Oregon, pollen records from Pacific Northwest lakes, and glacial records from western North America reveal climate events that appear to be related to the Heinrich events of the North Atlantic. This study will test two hypotheses: 1) that climate events originating in the North Atlantic are transmitted to the North Pacific Ocean and western North America via thermohaline circulation and its influence on surface ocean characteristics and circulation of the atmosphere, and 2) that climates of the North Atlantic, North America, and the northeast Pacific depend jointly on the elevation of the Laurentide Ice Sheet and its influence on atmospheric circulation. These hypotheses will be constrained by analyzing the paleoclimate record in a geographic array of sites in the northeastern Pacific Ocean and in western North America. Focus of this study will include: constraints on oceanic upwelling and near-surface advection, deep ocean properties and vegetation on land, and comparing these data with model output. A significant advance will come from linking the records from land and sea with a well- constrained chronology, and with stratigraphic links of pollen and terrigenous sediment in marine cores.