Research

Pliocene climate: North American Arctic (A. Csank)

My research into Pliocene climate focuses on the application of light stable isotopic and dendrochronologic techniques to exceptionally well preserved fossil material in order to reconstruct Pliocene climate. One goal of this study is to provide insight into interannual variability in climate during the Pliocene. I have used both stable oxygen isotope ratios of fossil molluscs and moss as well as the new 'clumped isotope' technique to reconstruct temperatures, published in Csank et al. (2011a). I have also examined stable isotope ratios of tree ring cellulose inorder to reconstruct annually resolved temperatures from a mid-Pliocene aged site on Ellesmere Island published in Csank et al (2011b) and from an early Pliocene site on Bylot Island published in Csank et al. (2013).

For media coverage of these articles see:
Arctic nearing greenhouse gas tipping point
Ancient fossils hold clues for predicting future climate change, scientists report
Arctic fossils provide clues to future climate
Arctic Climate May Be More Sensitive to Warming Than Thought, Says New Study

Empire, Trees and Climate in the North Atlantic (K. Greer, A. Csank)

 

I am invovled in a collaborative project with a research team consisting of historians and archeologists to look at climate in the North Atlantic Region using a mixed methods approach. We are looking at dendro-provenancing the wood from historic structures in Bermuda to assess where the timber came from, if not local. In partnership with the National Museum of Bermuda and the Bermuda department of Conservation Services I am also attempting to see if a multi-proxy approach can help develop a chronology from Bermuda cedar and if so what such a chronology can tell us about past climate of Bermuda.

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Reconstructing winter temperatures in the Rockies using tree-ring oxygen isotopes (C. Woodhouse, A. Csank, S. Leavitt)

 

In order to investigate the past it is useful to know what effects the isotopes in the modern. At present, no long-term, annually resolved reconstructions of winter temperature exist for the western United States, leaving a critical information gap in our understanding of the natural range of winter temperature variability. Recent studies provide evidence of a winter temperature signal in oxygen isotopes derived from tree-ring cellulose. I have begun work on sampling trees in Western Colorado and Montana with a known ring width response to winter precipitation. These trees will then be used to see if it is possible to reconstruct winter temperature using tree-ring derived oxygen isotopes.

Detection of long-term variability in storm tracks using seasonally resolved tree-ring isotope records: Implications for hydroclimatic change in the U.S. Pacific Northwest. (E. Wise, A. Csank, S. McAfee)

 

The trajectory of incoming storms from the Pacific Ocean influences precipitation patterns in the western United States, shaping drought and flood events. In this project, we are using seasonally resolved tree-ring data (based on earlywood and latewood widths, δ18O, and δ13C) and weekly precipitation isotope sampling at nearby sites to reconstruct storm-track position and moisture delivery pathways to the U.S. Pacific Northwest. These data will help us to better understand the role that changes in storm track trajectories have played in past drought and what the possible implications might be for future change.

Isotopic response to spruce beetle outbreaks in southwestern Alaska R. Sherrif, A. Csank, A. Miller)

 

The question of whether recent wide spread tree mortality in SW Alaska as a result of spruce beetle outbreak is an important question for forest managers and climate scientists alike. The goal of this project is to use stable carbon isotope ratios of tree rings from both live and dead trees to assess whether trees were already under stress as a result of drought conditions prior to beetle attack. We will also use oxygen isotopes as a proxy of vapour pressure deficit (VPD). This is an important question when assessing whether the recent large-scale beetle kills in SW Alaska are a result of changing climate or simply a natural effect related to beetle life cycles. I have a manuscript in review on this work

Eocene fossil wood

 

I have been involved in a project examining the isotopic characterization and climate analysis of Eocene wood that was found preserved in a kimberlite pipe in the Northwest Territories. This research was published in the journal PLoS One. Some news articles on this project can be found below 50-Million-Year-Old Redwood Chunk Found in Diamond Mine

Tree ring isotope networks

 

In order to investigate the past it is useful to know what effects the isotopes in the modern. To this end I have begun working on stimulating interest in an addition to the International Tree Ring Data Bank that will see tree-ring isotopic data added to the database. To that end I published a paper in Tree-Ring Research to stimulate interest in the tree-ring isotope community and highlight some of the possibilities inherent in having such a database.

ITRIDB Paper

Greenland: Age and source of riverine DOC (J. Welker, C. Czimczik, A. Csank)

 

For this project I have been conducting research into the age of Dissolved Organic Carbon (DOC) and Particulate Organic Carbon (POC) from rivers in northwestern Greenland using 14C. The goal of this project is to asses seasonal patterns in the age of DOC in order to study the processes governing the loss of soil carbon and make estimates of the importance of permafrost carbon to the total amount of carbon exported and to assess how Arctic carbon cycling could change with future climate change. I spent two summers at Thule AFB in Greenland collecting samples for this project and I am working with researchers from the University of Alaska Anchorage, University of Tennessee, University of California, Santa Barbara and the University of California, Irvine on this project. I currently have a manuscript in preparation on the results of this study.

Arctic Polar forests

Much of my research for the past several years has been focused on the study of ancient Polar forests. I have worked on Arctic fossil forests from the Cretaceous to the Pliocene. Polar forests are a facinating biome, up until the end of the Pliocene the entire Arctic was covered by vast forests, of which abundant fossil sites presently exist throughout the North American Arctic. It is my hope to continue in the study of the paleoclimate and the paleoecology of these fossil forests for some time to come.

Last updated: July 6th, 2015 if you have any problems, please contact me. Thanks.