SGER: Holocene Variability of the South Pacific Westerly Wind Field

该奖项由探索性研究小额赠款(SGER)计划赞助，将支持从拉戈费格纳诺收集一系列约3.0米长的湖泊沉积物岩心，用于“概念验证”分析，以确定哪些化学示踪剂(如果有的话)可能对未来的古气候研究最有用。拉戈费格纳诺位于火地岛的安第斯科迪勒拉山脉内，从东向西穿过阿根廷和智利的边界，是地球上最南端的大片(约120公里长)无冰淡水。拉戈法格纳诺位于现代全球南半球西风系统的路径上，受到热带、副热带和极地海洋-大气相互作用的影响。南半球西风被认为在调节大气二氧化碳浓度、冰川消融的时间和方式以及南美洲南部大部分地区的水文水量平衡特征方面发挥了重要作用。然而，关于过去这种环境变化的科学细节很少，所以这是一次有点冒险的探险。拉戈法格纳湖是一个深湖(270米)，位于高地形地貌的高降雨区，因此研究人员预计他们有很好的机会从湖中恢复高沉积速率的岩芯。这将有助于提供良好的年龄控制，这对来自湖心的校准良好的古气候记录至关重要。这位研究人员和他的同事将收集有关湖泊水深测量、沉积物分布和盆地尺度水文状况的基本信息，以限制与该地区相关的一些科学风险和不确定性。这位研究人员将与瑞士和美国的同事一起，利用高分辨率地震反射剖面图，结合有限的沉积物活塞式取心运动，利用可用的地球物理控制来识别合适的沉积物堆积，对Lago Fagnano进行初步的地球物理研究。如果研究人员能够检索到延续到过去的环境变化的高分辨率记录，这将有助于从具有潜在气候重要性的数据稀疏区域的新数据的角度推动古气候研究界向前发展。

This award, under the auspices of the Small Grants for Exploratory Research (SGER) program, will support the collection of a series of ~3.0 meter-long lake sediment cores from Lago Fagnano for a "proof-of-concept" analysis to determine which chemical tracers, if any, may be most useful for future paleoclimate studies. Situated within the Andean Cordillera of Tierra del Fuego, Lago Fagnano trends East to West across the boundary between Argentina and Chile and is the southernmost large (~120 km long) ice-free body of fresh water on Earth.Lago Fagnano lies in the path of the modern global southern hemisphere westerly wind system and is affected by tropical, subtropical, and polar ocean-atmosphere interactions. The Southern Hemisphere Westerly winds are thought to have played an important role in the regulation of atmospheric carbon dioxide concentration, the timing and style of deglaciation, and the character of the hydrologic water balance over much of southern South America. Scientific specifics are sparse regarding such past environmental variability, however, so this is a somewhat risky expedition. Lago Fagnano is a deep lake (270 meters) in a high rainfall region of high topographic relief so the researchers expect that they have a good chance of recovering high sedimentation rate cores from the lake. This will help provide good age control that is critical to a well-calibrated paleoclimate record from the lake cores. The researcher and his colleagues will collect basic information about lake bathymetry, sediment distribution, and the basin-scale hydrologic regime in order to constrain some of the scientific risks and uncertainty associated with the region. The researcher will join Swiss and American colleagues in conducting a preliminary geophysical study of Lago Fagnano, utilizing high-resolution seismic reflection profiling that will be combined with a limited sediment piston coring campaign using available geophysical control for identification of suitable sediment accumulations. If the researchers are able to retrieve a high-resolution record of environmental change extending into the past, this will help move the paleoclimate research community forward from the standpoint of new data from a data sparse region of potential climatic importance.