Collaborative Research: Pilot Study in Tropical Isotope Dendroclimatology

这项研究的科学战略利用稳定同位素树枝生态学、质谱学和分析化学的最新突破，在没有年轮的热带树木中开发年代学和气候代理数据。年轮记录已显示出很大的长期观测潜力(比现在早500年或更长时间)，但范围有限，因为许多热带树种间歇性地形成年轮或根本不形成年轮。这项研究的最终目标是开发印度尼西亚过去几个世纪降雨量变化的年度可分辨代理估计。这些数据预计将通过补充现有的由热带珊瑚和温带树木组成的替代数据网络，直接有助于观测过去厄尔尼诺-南方涛动(ENSO)的频率和强度的变化。热带是全球气候系统的重要组成部分，具有在季节到年际时间尺度上组织全球尺度气候异常的动力和能量。来自模型的证据表明，热带地区可能是全球气候变化在长时间尺度上的持续影响。热带气候的长期变化有可能影响整整四分之一世界人口的生活，主要是由于季节性正常降水和农业模式的中断。迄今为止，热带地区从季节到年度分辨率代理记录的最重要档案来自对珊瑚礁和冰芯的测量。然而，它们也有其局限性，因为几乎没有珊瑚记录早于现有的100-150年的历史观测记录，而冰芯记录虽然较早，但仅限于几个迅速消失的热带冰场。获得300-500年长的复制记录的前景仍然具有挑战性，但同位素树状气候学在缩小数据差距方面提供了巨大的希望，并以这种方式提供了对许多科学领域产生广泛影响的潜力。

The scientific strategy for this research exploits recent breakthroughs in stable isotope dendro-ecology, mass spectrometry, and analytical chemistry to develop chronological and climate proxy data in tropical trees that lack rings. Tree-ring records have shown great potential for long term observations (500 years before present or longer) but are limited in extent because many tropical tree species form rings intermittently or not at all.The ultimate goal of this research is to develop annually resolved proxy estimates of rainfall variability from Indonesia for the past several centuries. These data are expected to directly contribute to observations of past changes in frequency and strength of the El Nino-Southern Oscillation (ENSO) by complementing the existing proxy data network composed of tropical reef corals and extratropical trees. The tropics are an important component of the global climate system, possessing the dynamics and energetics to organize global-scale climatic anomalies on seasonal to interannual time scales. Evidence from models suggests the tropics may be a persistent influence of global climate variability on long time scales. Long-term variability in the tropical climate has the potential to affect the lives of fully a quarter of the world's population primarily through the interruption of seasonally normal precipitation and agricultural patterns. To date the most important archives for seasonal to annual resolution proxy records in the tropics have been derived from measurements from coral reefs and ice cores. They have their limitations, however, as few coral records predate the existing 100-150 year long historical observational record and ice core records, while older, are limited to a few rapidly disappearing tropical ice fields. Prospects for obtaining replicated 300-500 year long records remain challenging but isotope dendroclimatology offers great promise in closing the data gap and, in this manner, offers the potential for broad impact to many scientific fields.