Producing an enhanced millennium-length temperature reconstruction from tree-ring density for the European Alps

我将为欧洲阿尔卑斯山开发一种新的、改进的、基于千禧年轮最大晚材(MXD)的温度重建。迫切需要跨越整个过去千年的巧妙的、每年解析的代理记录，以将最近的变暖置于历史背景中，并与以不同方式强迫的中世纪暖期(MWP)进行比较。Büntgen等人。(2006)制作了欧洲阿尔卑斯山的MXD年表，导致了一次被高度引用和有影响的千年温度重建。然而，这项重建工作有一些关键的局限性，这些局限性将在该项目中加以解决和消除：(I)欧洲阿尔卑斯山活着的树木没有达到千年树龄，因此Büntgen等人使用了历史建筑的木材。(2006)将年表追溯到时间。然而，木材材料的确切来源是未知的，气候信号可能在树线和非树线地点的树木之间有所不同。我将沿着海拔横断面进行活树多点采样，并将活的基于树木的种源模型应用于历史材料，以估计其来源并获得稳健的气候信号。(Ii)Büntgen等人的基本样本。2006年)的记录来自瑞士不同的亚高山山谷，所有1200年前的样品都只来自Simplon地区的建筑，而最近的数据来自L地区的建筑和活着的树木。这些山谷之间的生态差异尚未得到评估，但很可能会影响年表和导出的温度重建，这反映在记录中的统计差异上。在这个项目中，我将根据来自Simplon山谷的生态同质数据制作MXD年表，以匹配覆盖整个MWP的现有数据。(3)Büntgen等人的样品复制。(2006)年表在公元1200年左右较低，强调个体树木的反应，减弱年表信号强度。我已经获得了涵盖这一关键时期的更多样本，并将开发一个复制良好且在时间上可靠的中世纪MXD年表。(4)作为Büntgen等人。重建工作将于2004年结束，不能用它来把最近最热的几十年放在一个长期的背景下。我将编制一份最新的千年温度重建报告，延长到2018年，并提供追溯到中世纪的强有力的估计。我与本特根等人的原始作者保持着密切的联系。(2006)文件，并将能够获得开展该项目所需的所有数据和元信息，以及以与原始数据完全相同的方式测量的MXD设备(DFG Groúgeräte Funding)，从而能够直接整合所有数据。新的千禧年尺度温度重建和基本数据将在出版后在适当的平台(国家海洋和大气局和ITRDB)上提供。

I will develop a new and improved millennium-length tree-ring maximum latewood (MXD) based temperature reconstruction for the European Alps. Skillful, annually resolved proxy records, spanning the entire past millennium, are urgently needed to place recent warming into a historical context and compare with the differently forced Medieval Warm Period (MWP). Büntgen et al. (2006) produced a MXD chronology for the European Alps, resulting in a highly cited and influential millennium-length temperature reconstruction. However, this reconstruction has crucial limitations which will be addressed and eliminate within this project: (i) Living trees do not reach millennial age in the European Alps, thus timbers from historical buildings were used by Büntgen et al. (2006) to extend the chronology back into time. The exact provenance of the timber material is, however, unknown and climate signals may vary between trees from treeline and non-treeline sites. I will perform a living tree multiple-site sampling along elevational transects and apply a living tree-based provenance model to the historical material for estimating its origin and to gain robust climate signals. (ii) The underlying samples in the Büntgen et al. (2006) record originate from different subalpine valleys in Switzerland, with all pre-1200 samples exclusively originating from buildings in the Simplon region, while the recent data is from buildings and living trees in the Lötschental. The ecological differences among these valleys have not been assessed, but very likely influence the chronology and derived temperature reconstruction, which is reflected by statistical discrepancies in the record. Within this project, I will produce a MXD chronology based on ecological homogenous data from the Simplon valley to match the existing data covering the entire MWP. (iii) Sample replication in the Büntgen et al. (2006) chronology is low around 1200 AD emphasizing individual tree responses and weakening the chronology signal strength. I already have access to additional samples covering this crucial period and will develop a well replicated and temporally robust MXD chronology back to Medieval times. (iv) As the Büntgen et al. reconstruction ends in 2004, it cannot be used to place the recent warmest decades into a long-term context. I will produce an updated millennium-length temperature reconstruction extended until 2018 and providing robust estimates back to Medieval times. I am in close contact to the original authors of the Büntgen et al. (2006) paper and will have access to all data and meta information needed to conduct this project and to a MXD device (DFG Großgeräte funding) that measures in the exact same way as the original data, allowing a direct integration of all data. The new millennial scale temperature reconstruction and the underlying data will be made available on appropriate platforms (NOAA and ITRDB) upon publication.