P2C2: Temperature and Hydroclimate Variability in Mid-Latitude arid Central Asia During the Past 13,600 years: a Multi-Proxy Investigation of Issyk-Kul (Kyrgyzstan)

干旱的中亚(ACA)将受到未来供水变化的强烈影响。随着降水量和类型(雪或雨)的变化以及人口的高增长，即将到来的气温上升预计将给该地区带来环境和经济压力。ACA是一个地理位置各异的地区，其中包括田山山脉(最高峰海拔7,439米)。地球上变暖的速度并不均匀，而且随着纬度和海拔的变化而变化；极地和高海拔地区变暖最快。大量的种群通常居住在低海拔地区，但往往依赖山上的径流作为水源。ACA的情况就是如此，那里的年降雨量很小，山脉和湖泊是关键的自然资源。出于这些原因，了解未来气候变化将如何影响ACA是很重要的。这项研究将在吉尔吉斯斯坦的一个大山湖Issuk-Kul产生跨越过去13,600年的温度、降水和植被记录。这些新的记录将揭示ACA过去的气候历史，并将促进对区域和全球气候过程的了解。需要提高对ACA过去中纬度气候动力学的了解，以更准确地预测未来条件。这项研究将通过与Eureka合作为初中和高中女孩提供实践暑期讲习班，支持扩大STEM中代表性不足群体的参与！科学夏令营，由山谷女孩公司(马萨诸塞州霍利奥克)和马萨诸塞州阿默斯特大学自然科学学院共同运营。夏季还将招待高中实习生，以获得实验室经验。伊塞克湖是世界上最大、最深的湖泊之一，代表了目前研究不足的古气候档案。这项研究将利用现有的沉积物岩心对Issyk-Kul进行多代理有机地球化学研究，以检验以下假设：在中期全新世最热时期和自1850年以来，该湖经历了比北半球平均水平更大的变暖；ACA在中期全新世期间从东亚夏季风中获得了水分；Issyk-Kul的藻类和微生物群落发生了变化，以响应气候变化。将产生数十年至百年尺度的古气候记录。基于甘油二烷基甘油四醚(GDGTS)的替代物将用于从退冰期和全新世的ACA生成定量温度重建，并结合植物蜡(正构烷烃)氘和碳同位素，分别作为主要水汽来源(西风带、西伯利亚高压和东亚夏季风)和植被类型(C3植物与C4植物)变化的替代。更好地理解古气候历史，Issyk-Kul将构成ACA古气候学的一个重大进步，因为ACA现有的记录很少，而且对时空变异性的了解很差。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Arid Central Asia (ACA) will be strongly affected by future changes in water supply. Impending temperature increases along with changes in precipitation amount and type (snow or rain), as well as high population growth, are expected to bring environmental and economic stress to the region. ACA is a region characterized by varying geography and includes the Tian Shan Mountains (highest peak 7,439 m). The rate of warming on Earth is not uniform and varies with latitude and altitude; the poles and high elevation regions are warming the fastest. Large populations typically reside in lower elevation regions but often depend on runoff from the mountains as a water source. This is the case for ACA, which receives a small amount of annual precipitation, and where mountains and lakes are critical natural resources. For these reasons, is important to understand how future climate change will affect ACA. This research will generate temperature, precipitation and vegetation records spanning the past 13,600 years from Issuk-Kul, a large mountain lake in Kyrgyzstan. These new records will reveal the past climate history of ACA and will advance understanding of regional and global climate processes. Improved knowledge of past mid-latitude climate dynamics in ACA is needed to predict future conditions more accurately. This research will support efforts to broaden participation from underrepresented groups in STEM by providing hands-on summer workshops for middle and high school girls in partnership with the Eureka! Science Camp, run by Girls Inc. of the Valley (Holyoke, MA) and the College of Natural Sciences at UMass Amherst. High school interns also will be hosted during summers to gain laboratory experience.Issyk-Kul, one of the world's largest and deepest lakes, represents a presently understudied paleoclimate archive. This research will provide a multi-proxy organic geochemical study of Issyk-Kul using existing sediment cores to test hypotheses including that the lake experienced greater warming compared to the Northern Hemisphere average during both the mid-Holocene thermal maximum and since 1850 AD, that ACA received moisture from the East Asian Summer Monsoon during the mid-Holocene, and that shifts in the algal and microbial communities of Issyk-Kul occurred in response to climate variability. Multi-decadal to centennial-scale paleoclimate records will be produced. Proxies based on glycerol dialkyl glycerol tetraethers (GDGTs) will be used to generate a quantitative temperature reconstruction from ACA over the deglaciation and the Holocene, in conjunction with plant wax (n-alkane) deuterium and carbon isotopes as proxies for shifts in the dominant moisture sources (the Westerlies, the Siberian High, and the East Asian Summer Monsoon) and vegetation type (C3 versus C4 plants), respectively. Better understanding the paleoclimate history Issyk-Kul will constitute a major advance in the paleoclimatology of ACA where there are few existing records and where spatial and temporal variability is poorly understood.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.