Emergence of an anthropogenic salinity signal in the IndoPacific

印度太平洋地区人为盐度信号的出现

• 批准号: 2303565
• 负责人: SARA SANCHEZ
• 金额: $ 44.23万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2303565&HistoricalAwards=false
• 关键词: Emergence; anthropogenic; salinity; signal; IndoPacific

Temperature changes in the Indian and Pacific Oceans have profound impacts on distant societies, ecosystems, and economies. The El Niño Southern Oscillation (ENSO) is a clear example. ENSO can cause temperature changes that prompt large shifts in global weather. It can influence heatwaves, droughts, floods, and storms. Despite the significance of the IndoPacific, it is still not clear how this region will respond to rising greenhouse gases. Climate models agree that human-caused climate change will alter global temperature and rainfall patterns. However, climate models often disagree on the magnitude and even the sign of those changes. Another challenge to understanding climate change in the IndoPacific is that internal variability can mask trends. Long records from the tropical oceans are essential to untangle this uncertain response, but few instrumental exist. This project develops new ways to evaluate climate change in the data-sparse regions of the IndoPacific. Coral data can provide information about past temperature and hydrological conditions. This project will synthesize centuries of data from corals, instrumental observations, and climate models. These data will be used to reconstruct climate variability. Reconstructions of temperature, salinity, and precipitation will be compared with climate model simulations. This research will bolster scientific understanding of the tropical hydrological cycle response to climate change. Finally, this work will support an early career scientist, a graduate student, and undergraduate researchers. This project will evaluate the emergence of an anthropogenic signal in the tropical IndoPacific by leveraging long, seasonally-resolved tropical coral records with instrumental observations in an offline paleoclimate data assimilation (paleo-DA) framework. The proposed work will utilize novel methods to synthesize diverse sources of data (paleoclimate proxies, reanalysis products, isotope-enabled models, large ensembles, paleo-DA) to evaluate the range of internal variability and changes in temperatures, salinity, and precipitation variability from the 18th-century to the present. In particular, this work seeks to fill a critical data gap linking sea surface salinity to coral oxygen isotopic records (d18Ocoral) and coral-derived reconstructions of the oxygen isotopic composition of seawater (d18Osw) at seasonal to multidecadal timescales. This project aims to rigorously quantify uncertainties related to using coral d18O and coral-derived d18Osw to examine historic hydroclimate change and to establish best practices for inferring relationships with sea surface salinity at a variety of timescales. Interpretation of the timing, magnitude, and spatial patterns associated emergence of an anthropogenic signal in the coral-derived reconstructions will be contrasted with CMIP6 Large Ensemble historical and anthropogenically forced simulations.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.

印度洋和太平洋的温度变化对遥远的社会、生态系统和经济产生深远影响。厄尔尼诺南方涛动（ENSO）就是一个很好的例子。厄尔尼诺/南方涛动可能导致温度变化，从而促使全球天气发生大的变化。它可以影响热浪，干旱，洪水和风暴。尽管印度太平洋地区具有重要意义，但目前尚不清楚该地区将如何应对温室气体排放的增加。气候模型一致认为，人类引起的气候变化将改变全球气温和降雨模式。然而，气候模型往往对这些变化的幅度甚至迹象持不同意见。了解印度洋太平洋地区气候变化的另一个挑战是，内部变化可能掩盖趋势。来自热带海洋的长期记录对于解开这种不确定的反应至关重要，但几乎没有仪器存在。该项目开发了新的方法来评估印度太平洋数据稀疏地区的气候变化。珊瑚数据可以提供有关过去温度和水文条件的信息。该项目将综合几个世纪以来来自珊瑚、仪器观测和气候模型的数据。这些数据将用于重建气候变异性。温度、盐度和降水的重建将与气候模式模拟进行比较。这项研究将加强对热带水文循环对气候变化反应的科学认识。最后，这项工作将支持早期职业科学家，研究生和本科研究人员。 该项目将通过利用长期的季节性分辨率热带珊瑚记录以及离线古气候数据同化（paleo-DA）框架中的仪器观测来评估热带印度洋太平洋地区人为信号的出现。拟议的工作将利用新的方法来综合不同来源的数据（古气候代理，再分析产品，同位素启用模型，大型合奏，古DA），以评估从18世纪到现在的温度，盐度和降水变化的内部变化和变化的范围。特别是，这项工作旨在填补一个关键的数据空白，连接海面盐度珊瑚氧同位素记录（d18 Ocoral）和珊瑚衍生重建的海水氧同位素组成（d18 Osw）在季节性到几十年的时间尺度。该项目旨在严格量化与使用珊瑚d18 O和珊瑚衍生的d18 Osw来检查历史水文气候变化有关的不确定性，并建立在各种时间尺度上推断与海面盐度关系的最佳实践。在珊瑚衍生重建的时间，幅度和空间模式相关的人为信号出现的解释将与CMIP 6大型围隔的历史和环境强迫simulation.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。