Nonlinear variability and regime shifts in Late Holocene climate

The proposed project will focus on the late Holocene climate variability in the multiproxy, observational and model data from the three specific regions where past climate variability has most likely exhibited complex signatures. These signatures have not yet been fully disentangled and explained in previous studies which have exploited at most linear methods of time series analysis. Specifically for this collaborative project three priority research areas have been identified: (1)Northern Atlantic circulation changes and terrestrial climate variability over Northwestern Europe - identify regime changes in terrestrial data over the NA basin, possibly linking them to ocean circulation variability (2)Expression and role of the bipolar seesaw during the late Holocene - test the hypothesis of a bipolar see-saw pattern during the late Holocene, constrain leads / lags in interhemispheric climate variations (3)Tropical ENSO to SAM teleconnections and the associated downstream effects on the climate in Antarctica. - identify possible gateways of decadal climate variability from the tropical Pacific (ENSO region) on the Southern Ocean (SAM and circumpolar current) Considering the data in a complex systems framework will allow the detection and potential attribution of past abrupt changes to nonlinear dynamical transitions in the climate system. In addition to such abrupt changes, complex spatio-temporal interdependence patterns among existing archives are equally relevant to unveil dynamical mechanisms that have been hidden to previously applied linear analysis techniques.