SGER: Holocene Variability of the South Pacific Westerly Wind Field

在探索性研究小额赠款（SGER）计划的支持下，该奖项将支持从Lago Fagnano收集一系列约3.0米长的湖泊沉积物岩心，进行“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。法尼亚诺湖位于火地岛的安第斯山脉内，自东向西穿过阿根廷和智利的边界，是地球上最南端的大型（约120公里长）无冰淡水水体。法尼亚诺湖位于现代全球南半球西风系统的路径上，受到热带、亚热带和极地海洋-大气相互作用的影响。南半球西风被认为在调节大气中二氧化碳浓度、冰川消退的时间和方式以及南美洲南部大部分地区的水文水平衡方面发挥了重要作用。然而，关于这种过去环境变化的科学细节很少，所以这是一次有点冒险的探险。Lago Fagnano是一个深湖（270米），位于高地形起伏的高降雨区，因此研究人员希望他们有很好的机会从湖中恢复高沉积率的核心。这将有助于提供良好的年龄控制，这是至关重要的一个良好的校准古气候记录从湖芯。研究人员和他的同事将收集有关湖泊水深、沉积物分布和流域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。该研究员将与瑞士和美国同事一道，利用高分辨率地震反射剖面法，对法尼亚诺湖进行初步地球物理研究，同时利用现有的地球物理控制手段，进行有限的沉积活塞取芯活动，以查明适当的沉积物堆积。如果研究人员能够检索到过去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.