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Dive into the research topics where Alexander Zapf is active.

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Featured researches published by Alexander Zapf.


Radiocarbon | 2013

Microgram-level radiocarbon determination of carbonaceous particles in firn and ice samples: pretreatment and OC/EC separation

Fang Cao; Yanlin Zhang; Soenke Szidat; Alexander Zapf; Lukas Wacker; Margit Schwikowski

Carbonaceous particles that comprise organic carbon (OC) and elemental carbon (EC) are of increasing interest in climate research because of their influence on the radiation balance of the Earth. The radiocarbon determination of particulate OC and EC extracted from ice cores provides a powerful tool to reconstruct the long-term natural and anthropogenic emissions of carbonaceous particles. However, this 14C-based source apportionment method has not been applied for the firn section, which is the uppermost part of Alpine glaciers with a typical thickness of up to 50 m. In contrast to glacier ice, firn samples are more easily contaminated through drilling and handling operations. In this study, an alternative decontamination method for firn samples consisting of chiselling off the outer parts instead of rinsing them was developed and verified. The obtained procedural blank of 2.8 ± 0.8 μg C for OC is a factor of 2 higher compared to the rinsing method used for ice, but still relatively low compared to the typical OC concentration in firn samples from Alpine glaciers. The EC blank of 0.3 ± 0.1 μg C is similar for both methods. For separation of OC and EC for subsequent 14C analysis, a thermal-optical method instead of the purely thermal method was applied for the first time to firn and ice samples, resulting in a reduced uncertainty of both the mass and 14C determination. OC and EC concentrations as well as their corresponding fraction of modern for firn and ice samples from Fiescherhorn and Jungfraujoch agree well with published results, validating the new method.


Quaternary Science Reviews | 2013

The onset of Neoglaciation 6000 years ago in western Mongolia revealed by an ice core from the Tsambagarav mountain range

Pierre-Alain Herren; Anja Eichler; Horst Machguth; Tatyana Papina; Leonhard Tobler; Alexander Zapf; Margit Schwikowski


Journal of Glaciology | 2012

Carbonaceous particles reveal that Late Holocene dust causes the dark region in the western ablation zone of the Greenland ice sheet

I. G. M. Wientjes; R. S. W. van de Wal; Margit Schwikowski; Alexander Zapf; Simon Fahrni; Lukas Wacker


Journal of Glaciology | 2016

Abrupt and moderate climate changes in the mid-latitudes of Asia during the Holocene

Elena M. Aizen; Vladimir B. Aizen; Nozomu Takeuchi; Paul Andrew Mayewski; B. Grigholm; Daniel R. Joswiak; Stanislav A. Nikitin; Koji Fujita; Masayoshi Nakawo; Alexander Zapf; Margit Schwikowski


The Cryosphere | 2016

Radiocarbon dating of glacier ice: overview, optimisation, validation and potential

Chiara Uglietti; Alexander Zapf; Theo M. Jenk; Michael Sigl; Sönke Szidat; Gary Salazar; Margit Schwikowski


Radiocarbon | 2013

14C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a 14C Dating Technique for Glacier Ice

Alexander Zapf; Atle Nesje; Sönke Szidat; Lukas Wacker; Margit Schwikowski


The Cryosphere Discussions | 2016

Radiocarbon dating of glacier ice

Chiara Uglietti; Alexander Zapf; Theo M. Jenk; Sönke Szidat; Gary Salazar; Margit Schwikowski


Archive | 2015

The controversial age of Kilimanjaro's plateau glaciers

Chiara Uglietti; Alexander Zapf; Sönke Szidat; Gary Abdiel Salazar Quintero; Douglas R. Hardy; Margit Schwikowski


Archive | 2012

Microgram level radiocarbon (14C) determination of carbonaceous particles in firn samples: towards pretreatment and OC/EC separation

Fang Cao; Yanlin Zhang; Alexander Zapf; Sönke Szidat; Lukas Wacker; Margit Schwikowski


Archive | 2012

14C measurements of ice samples from the „Juvfonne Ice Tunnel“, Norway - a validation of a radiocarbon dating technique for glacier ice

Alexander Zapf; Atle Nesje; Sönke Szidat; Lukas Wacker; Margit Schwikowski

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Anja Eichler

Paul Scherrer Institute

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Tatyana Papina

Russian Academy of Sciences

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Theo M. Jenk

University of Copenhagen

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Fang Cao

Nanjing University of Information Science and Technology

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