(NORKLIMA Theme 1: Polar Klimaforskning)
Co-ordinator: Eystein Jansen
Scientific project manager: Carin Andersson Dahl
The aim of ARCTREC is to investigate past warm and cold periods with different forcing and boundary conditions than at present to determine the influence of atmosphere and ocean dynamics and key Arctic feedbacks on Arctic climate variability, from a wider range of conditions than available at present and in the recent past. This will be done by integrating climate model experiments focused on understanding the specific processes and feedbacks at play, with tailored climate-proxy time series from lake sediments, marine cores and Greenland ice cores from within and around the European Arctic. The emphasis is on the last deglaciation and the early part of the Holocene (15-7 ka), which are times of strongly contrasting climate boundary conditions and forcings. We will extract the critical palaeo proxy data, which will test model hypotheses with empirical evidence for atmospheric and oceanic circulation and seasonality. By assimilating proxy data we will reconstruct: 1. the spatial and seasonal temperature distribution of the Nordic Seas, European Arctic Ocean and adjacent land areas in Europe and Greenland; 2. winter precipitation in Northern Europe and Greenland; 3. prevailing wind directions; 4. advection of Atlantic water to the Arctic. The proxy-data will be quality controlled and collated into a common database. The combined climate reconstruction time series and empirical information from statistical analyses will be confronted with the model data to identify the degree of consistency of model simulations with the available proxy evidence. In this process we will utilise the new reconstructions of Atlantic advection into the Arctic, sea ice extent, summer surface temperature, seasonality and winter precipitation together with model simulations to identify key natural components of Arctic climate variability.