Micron-scale Ice Core Reconstruction of Abrupt Climate Changes

Multi-elemental ice core LA-ICP-MS impurity profile across abrupt climate change events.


As one of the most important natural archives, polar ice cores have led to the discovery of past abrupt climate transitions, such as the abrupt onset of stadial-interstadial warming in Greenland.

Due to continuous thinning of ice layers with depth, fine spatial resolution is paramount to study the sequence of events at adequate temporal detail.

At this high resolution, it is pivotal to take into account the interaction of impurities with the ice crystal matrix.
This is the main challenge addressed in the project MICRO-CLIMATE.

Polar ice core.


MICRO-CLIMATE focuses on the analysis of selected stadial-interstadial transitions in Greenland ice cores, the so-called “Dansgaard-Oeschger events”

  • In Venice, imaging the 2D impurity distribution investigates the imprint of the ice matrix. Disentangling this imprint offers an improved interpretation of the stratigraphic signals obtained from high-resolution profiles measured along the main core axis. 
  • In Maine, impurity profiles over meter-long ice core rods are obtained to decipher the timing of changes in marine, terrestrial and atmospheric proxies, before, during and after abrupt transitions. The ultimate goal is to investigate a high-resolution fingerprint of the abrupt change in order to decipher which climate components change first, and which follow.
  • Ultimately, the project will advance our understanding of how to interpret ice core geochemistry at high-resolution and produce a refined LA-ICPMS application that can be employed in upcoming ice core projects.
  • The partners will also collaborate on technological developments around LA-ICP-MS ice core analysis.
The combination of line profiles and imaging can reveal a new level of detail about the climatic signals in the ice core stratigraphy.


  • Bohleber, P., Dallmayr, R., Rittner, M., Roman, M., Stoll, N., Wilhelms, F. & Barbante, C. (2022). The breakthrough potential of LA-ICP-MS for understanding the chemical stratigraphy in deep polar ice cores. European Workshop on Laser Ablation, Bern. https://www.ewla2022.ch/programme/programme
  • Bohleber, P., Roman, M., Stoll, N., Larkman, P., Stenni, B., Delmonte, B. & Barbante, C. (2022). Imaging the 2D trace elements distribution in polar ice cores to assess the preservation of the paleoclimate record. 1° Congresso Società Geochimica Italiana, Genova. http://www.societageochimica.it/en/program
  • Bohleber, P., Stoll, N., Delmonte, B., Pelillo, M., Roman, M., Siddiqi, K., Stenni, B., Vascon, S., Weikusat, I. & Barbante, C. (2022). Glacio-chemical signature of grain boundaries and insoluble particle aggregates in ice core 2D impurity imaging (No. EGU22-4492). Copernicus Meetings. https://meetingorganizer.copernicus.org/EGU22/EGU22-4492.html
  • Stoll, N., Bohleber, P., Hörhold, M., Erhardt, T., Eichler, J., Roman, M., Delmonte, B., Barbante, C. & Weikusat, I. (2022). Integrating Raman spectroscopy and LA-ICP-MS 2D imaging to decipher the localisation and chemistry of impurities on the micro-scale in Greenland ice: Consistencies and open question (No. EGU22-5035). Copernicus Meetings. https://meetingorganizer.copernicus.org/EGU22/EGU22-5035.html


MICRO-CLIMATE brings together, for the first time, two state-of-the-art LA-ICP-MS setups, established at the Climate Change Institute, University of Maine, USA and at Ca’ Foscari University of Venice, Italy. This combination of two unique setups can realize what one partner could not achieve alone: 

  • The unique large cryocell at the Climate Change Institute permits the analysis of 1 m long rods of ice core. This setup delivers high-throughput, micron-scale stratigraphic analysis of the ice core geochemical layering. 
  • The LA-ICP-MS system in Venice has been uniquely optimized for high-resolution 2D chemical imaging on ice cores. This high detail in two dimensions permits constraining signal preservation.
  • In addition, a secondment at the Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany focuses on a comparison of LA-ICP-MS against a complementary method, cryo-Raman spectroscopy to deliver an improved understanding of the LA-ICP-MS chemical images. 
Two unique LA-ICP-MS setups collaborate on the ice core analyses.


Pascal Bohleber

Ca' Foscari University of Venice, Department of Environmental Science, Informatics and Statistics (Italy)

Carlo Barbante

Project advisor
Ca' Foscari University of Venice, Department of Environmental Science, Informatics and Statistics (Italy)

Paul Mayewski

Secondment supervisor
Climate Change Institute, University of Maine (USA)

Ilka Weikusat

Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven (Germany)
Eberhard Karls University Tübingen (Germany)