Isotope; Emanation; Stable Isotope; Cosmogenic production; Dating; Underground production; Low level counting; Tracing environmental processes; Climate reconstruction; Hydrology; Atmosphere
Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1957-2018; obspack_co2_1_GLOBALVIEWplus_v5.0_2019_08_12
A full list of all contributors for this product can be found at www.esrl.noaa.gov/gmd/ccgg/obspack/providerlist/obspack_co2_1_GLOBALVIEWplus_v5.0_2019-08-12.html. This product is constructed using the Observation Package (ObsPack) framework [Masarie et al., 2014; www.earth-syst-sci-data.net/6/375/2014/]. The framework is designed to bring together atmospheric greenhouse gas (GHG) observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. ObsPack products are intended to support GHG budget studies and...
| Author |
Arosio, Tito; Ziehmer, Malim; Nicolussi, Kurt; Schlüchter, Christian; Thurner, Andrea; Österreicher, Andreas; Nyfeler, Peter; Leuenberger, Markus |
| Publication date |
30.03.2022 |
| Persistent Identifier (PID) |
https://doi.pangaea.de/10.1594/PANGAEA.941604 ((dataset in review)) |
| Repository |
PANGAEA
|
| Abstract |
Stable isotope ratios from tree rings are important proxies of past climate variations. We have access to a calendar-dated wood material from wood collected at glacier forefields and peat bog sites located in the Alps. They are of two species, larch (Larix decidua) and cembran pine (Pinus cembra). All the wood samples were collected at high altitudes in the Swiss and Tyrol Alps, they cover the whole Holocene period and belong to the Eastern Alpine Conifer Chronology Dataset (Nicolussi et al., 2009; doi:10.1177/0959683609336565). We analysed the δ13C, δ18O and δ2H isotope ratios of alpha cellulose obtained from blocks of 5 annual rings from 203 trees. Cellulose was extracted following the modified Jayme-Wise method (Boettger et al., 2007; doi:10.1021/ac0700023). The isotopes values were determined using conventional Isotope Ratio Mass Spectrometry (Isoprime 100) coupled to a pyrolysis unit (HEKAtech GmbH, Germany), which is similar to the previously used TC/EA (for technical details see (Leuenberger 2007). This approach was extended to measurements of non-exchangeable hydrogen of alpha-cellulose using the on-line equilibration method (Filot et al., 2006 (doi:10.1002/rcm.2743); Loader et al., 2015(doi:10.1021/ac502557x)). The results are reported in per mil (‰) relative to the Vienna Pee Dee Belemnite (VPDB) for carbon and to Vienna Standard Mean Ocean Water (VSMOW) for hydrogen and oxygen (Coplen 1994; doi:10.1351/pac199466020273). For all the δ13C values after 1000 CE we applied the factor described in Leuenberger (2007; doi:10.1016/S1936-7961(07)01014-7) to correct for the δ13C depletion of CO2 caused by the Industrial Revolution from about 1850 onwards (Leuenberger, 2007).
Isotope studies have considerably increased over the last decades mainly due to the development of online preparation systems and new detector methods such as laser based instruments. Yet, for many applications mass spectrometric isotope ratio measurements are still state-of-the-art. Recent analytical developments in our groups allow a more detailed quantification of past temperature variations based on climate proxies and characterization of biogeochemical cycles. The goal of the project isotopes in Earth System Science (isoCEP) is to extend these new analytical tools and to apply them to four paleo archives, namely ice cores, tree rings, ground water and speleothems as well as to direct atmospheric air samples in order to enhance the process understanding of the Earth’s Climate System. This includes (i) quantification of temperature variations based on air nitrogen and argon isotopes (d15N and d40Ar) extracted from polar ice focussing on the Holocene period; (ii) quantification of water stable isotopes (d17O, d18O, d17O, dD) of speleothem fluid inclusions and build-up of an expertise of clumped isotope applications related to the above mentioned archives and on biogeochemical processes, i.e. photosynthesis/respiration, fossil fuel oxidation etc.; (iii) measurements of triple isotopes (d13C, d18O and dD) to complete the Holocene records of tree ring finds from forelands of retreating alpine glaciers; (iv) quantification of direct atmospheric air composition and (v) quantification of subsurface production rates of argon isotopes in order to enhance the robustness of argon isotope interpretations related to groundwater dating and reconstructions of recharge conditions in the past. We will address two main objectives by investigations of these five different research topics. First, we aim to improve the robustness of Holocene temperature reconstructions and to better understand their spatial differences and gradients. Therefore, we will perform measurements from four paleo archives polar ice cores, groundwater aquifers, mid-latitude tree rings and low-mid latitude speleothems that exhibit the necessary spatial and vertical coverage. Second, since the understanding of biogeochemical processes is the key to correctly read and interpret past variations of climate proxy data, we will deepen this understanding by process specific experiments including clumped besides conventional isotope ratio measurements complemented by gas concentration analyses. This also includes linking past variations with present-day measurements and comparisons with in-house model results. These five different research topics and associated data streams allow us to capture - though still incompletely - the complexity of the Earth’s Climate Systems. In collaboration with our partners and colleagues from the Climate and Environmental Physics Division and with regard to their proposed work submitted in parallel to this proposal, we optimize the outcome from both, the experimental and model, perspectives.