Collaborative Research: Past and Present Climatic Controls on the Stable Isotope Composition of Precipitation at Low Latitude Proxy Sites

该奖项有助于建立在研究人员以前由NSF资助的关于稳定水同位素的气候控制研究的基础上（即，δ 18-氧，δ氘）。研究人员的主要科学目标是评估各种低纬度冰芯位置（即，热带安第斯山脉，西藏，喜马拉雅山）在现代世界和过去。这将有助于解决一些争议的解释来自热带冰芯的古气候记录。具体的研究目标包括：--研究温度、降水量效应、水汽源变率和大气环流等现代气候对热带冰芯稳定同位素的控制作用，分析厄尔尼诺-南方涛动（ENSO）或亚洲季风强度等气候模态对稳定同位素变率的影响，（中全新世条件）对稳定同位素分布和与热带冰芯有关的潜在气候控制的影响，--调查末次冰期最大值（LGM）的影响低纬度稳定同位素分布的边界条件，规定新的和更现实的重建冰川热带海表温度（SST）数据，- 探索使用热带冰芯中的氘过量作为改善热带海洋条件重建的额外气候代用指标，通过将模拟结果与现有的代用数据和国际原子能机构-全球降水同位素网络进行比较，进行模式评估（IAEA-GNIP）和国家环境预测中心-国家大气研究中心（NCEP-NCAR）现代实验的再分析数据。所有实验将基于GISS II（4度纬度x5度经度，对安第斯山脉的地形控制有新的改进）模式和欧洲中心-汉堡ECHAM-4（T30和T106光谱分辨率）模式。 这项研究将提供更好的了解古气候记录，用于帮助了解自然气候变化相比，人为对气候的影响。这项研究产生的数据和模型输出将通过世界古气候数据中心A提供给更广泛的科学界。

This award helps build upon the researchers' previously NSF-funded research on the climatic controls on stable water isotopes (i.e., delta 18-Oxygen, delta Deuterium) in precipitation at low latitude proxy sites. The researchers' main scientific goal is to evaluate the controls on stable isotope variability at various low latitude ice core locations (i.e., Tropical Andes, Tibet, Himalaya) in the modern world and in the past. This will help to resolve some of the controversy surrounding the interpretation of paleoclimate records derived from tropical ice cores. Specific research goals include:-- investigating the modern climatic controls such as temperature, precipitation volume effect, moisture source variability and atmospheric circulation on stable isotopes at tropical ice core sites and analyzing the influence of climate modes such as El Nino-Southern Oscillation (ENSO) or Asian monsoon intensity on stable isotope variability,-- analyzing the influence of changed orbital parameters (mid-Holocene conditions) upon stable isotope distribution and potential climatic controls related to tropical ice cores,-- investigating the effect of Last Glacial Maximum (LGM) boundary conditions upon low latitude stable isotope distribution by prescribing new and more realistic reconstructions of glacial tropical sea surface temperature (SST) data,-- exploring the use of the Deuterium excess in tropical ice cores as an additional climate proxy for improved reconstructions of tropical oceanic conditions, and-- performing model evaluation by comparing the simulated results with the available proxy data and with International Atomic Energy - Global Network of Isotopes in Precipitation (IAEA-GNIP) and National Center for Environmental Prediction - National Center for Atmospheric Research (NCEP-NCAR) reanalysis data for the modern experiments.All experiments will be based on the GISS II (4 degrees latitude x 5 degrees longitude, with new improved topographic control over the Andes) model and the European Center-Hamburg ECHAM-4 (T30 and T106 spectral resolution) models. This research will provide improved understanding of paleoclimatic records that are used to help understand natural climate variability compared to anthropogenic influences on climate. The data and model output resulting from this research will be made available to the wider scientific community through the World Data Center-A for Paleoclimatology.