Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany
Heidelberg Center for the Environment HCE, Heidelberg University, 69120 Heidelberg, Germany
Abstract. Stable hydrogen isotopes ratios of lignin methoxyl groups (expressed as δ2HLM) of wood have been shown to reflect the climate-sensitive δ2H values of precipitation (expressed as δ2Hprecip) modulated by a large uniform negative isotope fractionation. However, a detailed calibration study among temporal variabilities of δ2HLM in tree-ring series, site-specific δ2Hprecip and climate parameters has not been performed yet. Here, we present annually resolved δ2HLM values from nine tree-ring series (derived from four Fagus sylvatica L. trees) collected near stations of the Global Isotope Network of Isotopes in Precipitation (GNIP) and the Deutsche Wetterdienst (DWD) meteorological observatory at Hohenpeißenberg (southern Germany; ~ 48° N, 11° E). The measured nine δ2HLM tree-ring series (common period of overlap 1916-2015) show a strong coherency as indicated by highly significant (p < 0.001) inter-series correlations (mean value Rbar = 0.52) and no indication of any known (stable isotope-specific) juvenile trend affecting the first decades of growth. When compared to local instrumental data, the combined δ2HLM chronology shows highest correlations with annually averaged data of δ2Hprecip as well as temperature particularly when using the year defined from previous September to current August (r = 0.73 and 0.56, respectively, p < 0.001). However, the Hohenpeißenberg δ2HLM chronology shows enhanced correlations with land and sea surface air temperature for multiple (broadly combined) areas across Western Europe (r > 0.6, p < 0.1). We subsequently established a linear regression model between averaged Western European surface air temperatures (range: 30° W–20° E, 35–60° N) and the δ2HLM chronology (r = 0.71, p < 0.001). When comparing instrumental and reconstructed large-scale temperature anomalies from the year 1916 to 2015, an average absolute deviation in annual reconstructions of as low as 0.3 °C was found (n = 100). Therefore, δ2HLM values of mid-latitudinal tree-ring archives are considered suitable for large-scale mean annual temperature reconstructions and are therefore able to improve the paleoclimatic potential of Late Holocene tree-ring archives.
How to cite. Anhäuser, T., Sehls, B., Thomas, W., Hartl, C., Greule, M., Scholz, D., Esper, J., and Keppler, F.: Annually resolved δ2H tree-ring chronology of the lignin methoxyl groups from Germany reflects averaged Western European surface air temperature changes, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2019-8, 2019.
Received: 18 Jan 2019 – Discussion started: 04 Feb 2019