A new regional paleo-precipitation proxy: oxygen isotopes in desert nitrate

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。一个新的区域古降水代理：沙漠硝酸盐中的氧同位素Gregory Michalski普渡大学地球物理系-0922114摘要也许气候学家、政策制定者和人类面临的最重要的未回答的问题是，预期的全球变暖将如何影响区域降雨模式？ 我们评估干旱地区的降水模式在一个更温暖的世界中可能如何变化的最佳工具是使用代理验证的全球和区域气候模型。 因此，必须制定新的气候代用指标，反映当地区域降水量随时间和空间的变化。 拟议的研究将证明土壤硝酸盐中的17 O同位素异常如何可用作平均年降水量的敏感的新代理36 Cl日期阿塔卡马沙漠土壤是~ 100万年。 这一新的替代指标将用于评估过去百万年中厄尔尼诺气候异常，分辨率约为3,000年。该决议如果足够精细，可以捕捉到轨道交通引起的气候变化影响， 岁差和轴向倾斜，同时足够长的时间来捕捉最后5个轨道偏心率（完整的米兰科维奇周期），这是很少有地面代理可以捕捉到的壮举。 拟议的研究将大气化学与气候学联系起来，并将提供真实的数据，以评估化学传输-气象耦合模型，如目前正在由NOAA、EPA和其他非政府组织开发的WRF-Chem。 该研究将突出新的应用程序使用？17 O异常到更广泛的科学界。 其主要成果是更好地了解区域降水如何可能随着未来几十年预期的全球变暖而变化。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).A new regional paleo-precipitation proxy: oxygen isotopes in desert nitrateGregory MichalskiPurdue UniversityEAR - 0922114ABSTRACTPerhaps the most important unanswered question facing the climatologists, policy makers, and humanity at large is how will the anticipated global warming impact regional rainfall patterns? Our best tool for assessing how precipitation patterns in arid regions are likely to change in a warmer world is by using proxy validated global and regional climate models. Therefore it is imperative that new climate proxies that reflect local-regional precipitation variations over time and space be developed. The proposed research will demonstrate how 17O isotopic anomalies in soil nitrate can be used as a sensitive new proxy of mean annual precipitation in 36Cl dated Atacama Desert soils that are ~ 1,000,000 years old. This new proxy will be used to assess El Nino climate anomalies over the past million years at approximately 3,000 year resolution. This resolution if fine enough to capture climate change impacts arising from orbital precession and axial tilt, and at the same time lengthy enough to capture the last 5 orbital eccentricities (the full Milankovitch cyclcle), a feat few terrestrial proxies can capture. The proposed research links atmospheric chemistry to climatology and will provide real data to assess coupled chemical transport-meteorological models such as WRF-Chem, currently under development by NOAA, EPA and other NGO¡¦s. The research will highlight the new applications using ?´17O anomalies to a wider science community. The main outcome is a better understanding of how regional precipitation might change with the anticipated global warming in the coming decades.