WP7: Past long-term changes in the Arctic


WP-leader: Heikki Seppä, email: heikki.seppa (at) helsinki.fi

Co-WP-leader: Margareta Hansson, email:  margareta.hansson (at) natgeo.su.se

Co-WP-leader: Elisabeth Isaksson, email: elisabeth.isaksson (at) npolar.no

Co-WP-leader: Atte Korhola, email: atte.korhola (at) helsinki.fi


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The objective is to incorporate the view of the long-term Arctic change, especially linking the Greenland and Svalbard ice-core records and lake sediments. We’ll combine physical (predictor) and biological (response) proxy methods for reconstructing and exploring Arctic changes in the past and future. More specifically, we aim:

-to quantify past variations in short-lived agents, e.g. insoluble (BC, soot) and soluble (sulfates, nitrates and chlorides) particles on several timescales (from seasonal to millennial) in the Holocene and relate these to present day concentrations and modern climate

-to use the available millennial-scale climate data, especially the temperature record, from the Greenland ice cores, as the long-term predictor of Arctic environmental change, and explore the key long-term environmental and ecosystem dynamics, such as the Arctic tree-line response, in relation to changing climate and cryosphere

-to explore the feedback processes associated with the large-scale environmental changes in the circumpolar Arctic region. This is done by using the recent Greenland ice-core –based temperature reconstruction as the independent climatic predictor, and by combining existing palaeoecological records from the circumpolar region, to create Holocene time-series maps depicting the location of the Arctic treeline as a function of time, calculating the areal change of the Arctic and Boreal regions, and as an ultimate aim, modeling to simulate the resulting change of albedo and biogenic aerosol precursors. This approach can predict the corresponding ecosystem/albedo change in the future under predicted warm conditions.