Collaborative Research: Correcting sea surface temperature proxies for seasonal biases: combined data and model investigation

合作研究：修正海面温度代理的季节性偏差：结合数据和模型研究

• 批准号: 2202860
• 负责人: Zhengyu Liu
• 金额: $ 11.6万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202860&HistoricalAwards=false
• 关键词: Collaborative; Research; Correcting; sea; surface

Warmer than present periods in Earth history can provide insight into how the climate system will respond to rising global temperatures. Knowledge of ocean conditions during past warm periods comes, in large part, from geochemical records (proxies) of past sea surface temperature. These proxies are generally interpreted to reflect the average yearly temperature. Many SST proxies suggest that prior to the industrial revolution, global temperatures had been cooling for 6000 years. This result is at odds with climate model simulations which show warming over that period in response to rising atmospheric greenhouse gas levels. This mismatch has cast doubts on model predictions of future climate change and the warming impact of greenhouse gases. However, a recent study suggested the mismatch arises from the interpretation of the proxies, not from problems with the climate models. That study suggested that proxies often record temperature during a particular season, rather than the yearly average. When the seasonality of the proxy was considered the models and proxies were consistent. This study will test and refine approaches for extracting the seasonal and mean annual temperature from proxies of past sea surface temperatures. In addition, new geochemical records of past temperature will be produced across three recent warm periods in Earth history. These new data will aid in ground-truthing model predictions of future climate change. The project will also provide training opportunities for early career scientists, including students from underrepresented groups in the sciences. Results from the project will be communicated via public lectures and a K-12 science outreach program.Accounting for seasonal biases in sea surface temperature (SST) proxies is critical for understanding the drivers of SST in response to internal and external forcings. The proposed work aims to provide a way forward to identify seasonal biases and remove them from proxy SST records to improve paleoceanographic reconstructions. The study will include a series of test of the seasonal to annual mean transformation method in fully coupled and idealized climate models to explore the impact of ice sheet forcing, greenhouse gases, nonlinearities in the climate system, and sampling errors on the efficacy of the method in different regions of the global ocean and during multiple interglacial periods. The study will produce new paired foraminifer-magnesium/calcium and alkenone derived SST records from seven locations. At each of these sites, data from the Holocene, last interglacial, and Marine isotope stage 9 will be used to explore the stability of biases and the drivers of seasonal and mean annual climate change during multiple examples of a warm interglacial.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.

地球历史上比目前时期的温暖可以洞悉气候系统将如何应对全球温度上升的响应。过去温暖时期的海洋状况知识在很大程度上来自过去海面温度的地球化学记录（代理）。这些代理通常被解释为反映平均年度温度。许多SST代理表明，在工业革命之前，全球温度一直在冷却6000年。该结果与气候模型模拟不一致，这些模型在这段时间内显示出对大气温室气体水平上升的响应。这种不匹配对未来气候变化和温室气体变暖影响的模型预测产生了怀疑。但是，最近的一项研究表明，不匹配是由对代理的解释而不是气候模型的问题引起的。该研究表明，代理通常在特定季节记录温度，而不是年平均水平。当考虑到代理的季节性时，这些模型和代理是一致的。这项研究将测试和完善方法，从过去的海面温度的代理中提取季节性和平均温度。此外，在地球历史上最近三个温暖时期将产生过去温度的新地球化学记录。这些新数据将有助于对未来气候变化的地面流动模型预测。该项目还将为早期职业科学家提供培训机会，包括科学中代表性不足小组的学生。该项目的结果将通过公开讲座和K-12科学外展计划进行传达。对海面温度（SST）代理的季节性偏见的计算对于理解SST响应内部和外部强迫的驱动因素至关重要。拟议中的工作旨在为识别季节性偏见并将其从代理SST记录中删除，以改善古环摄影重建。该研究将包括一系列对季节到年度平均转化方法的测试，以完全耦合和理想化的气候模型，以探索冰盖强迫，温室气体，气候系统中的非线性的影响以及对该方法有效性的采样误差在全球海洋的不同地区以及多个冰间时期。这项研究将产生新的配对有孔虫 - 镁/钙，烯酮从七个位置产生的SST记录。在这些站点中的每个地点，全新世，最后一次冰期和海洋同位素第9阶段的数据将用于探索偏见的稳定性以及季节性和平均气候变化的驱动因素，在多个温暖的冰川间奖中反映了NSF的奖项。法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准来评估的值得支持的。