P2C2: Paleoclimate Data Assimilation

记录和理解气候系统过去的行为为与未来潜在的气候变化进行比较提供了重要的参考。由于仪器测量的记录仅涵盖最近100-150年，因此必须考虑间接(“代理”)测量。这些代用数据的定量分析面临着挑战，因为这些代用数据适用于特定的地点，而且它们与气候系统主要特征的关系没有得到很好的理解。在这个项目中，来自华盛顿大学的研究人员利用天气预报社区最先进的工具，通过一种称为古气候数据同化(PDA)的方法，在最近的进展基础上重建了过去的气候状态。这项研究涉及将气候模型和代理数据的信息进行最佳融合，以在广泛的时间范围内重建地球气候。PDA提供了将不规则间隔的逐点数据转换为全球网格数据的转换合成，类似于从天气观测派生的再分析产品。重建的气候状态将用于假设检验，使用数值模型来评估气候敏感性和可预测性，在十年和更长的时间尺度上，在广泛的气候状态下具有稳健的样本量。这项研究利用了古气候和气候动力学领域的专业知识。将通过与Pages(过去的全球变化)社区的互动，开展进一步的跨学科合作。资金支持研究生的教育和培训，以及面向学校、社区组织和国家机构的外联活动。

Documenting and understanding the past behavior of the climate system provides a critical reference for comparison with future potential climate change. Since the record for instrumental measurements covers only the most recent 100-150 years, indirect ("proxy") measurements must be considered. Quantitative analysis of these proxy data is challenged by the fact that the proxies apply to specific locations, and their relationship to the main feature in the climate system are not well understood.With this project, researchers from the University of Washington build on recent progress in using state-of-the-art tools from the weather prediction community to reconstruct past climate states by a method referred to as paleoclimate data assimilation (PDA). The research involves optimally blending information from climate models and proxy data to reconstruct Earth's climate over a wide range of time scales. PDA provides a transformative synthesis of irregularly spaced pointwise data into global gridded data, similar to reanalysis products derived from weather observations. Reconstructed climate states will be used for hypothesis testing using numerical models to evaluate climate sensitivity and predictability on decadal and longer timescales with robust sample sizes over a wide range of climate states. This research leverages expertise from both the paleoclimate and climate dynamics communities. Further interdisciplinary collaboration will take place through interactions with the PAGES (PAst Global changES) community. Funding supports education and training of a graduate student, as well as outreach activities to schools, community organizations and state agencies.