Abstract:
Strong chronological constraints and preservation of climate information in ice core and tree-ring records makes it feasible to produce climate field reconstructions using assimilation techniques similar to those of meteorological reanalysis. Here I will show updated reconstructions for the North Atlantic region of sea level pressure and temperature covering the time frame CE 1241-1970. The reconstructions are based on seasonal ice core data, tree-ring isotope records, as well as conventional tree-ring records coupled to an isotope enabled climate model. First, I will discuss implications of seasonality, choice of proxy data, role of climate variability and climate model biases based on an extension of previous work. A clear feature of the seasonal reconstructions is that they show significant skill in reproducing the spatial and temporal variability of the main modes of sea level pressure, namely, the North Atlantic Oscillation (NAO), Eastern Atlantic Pattern, and Scandinavian Blocking, as well as the temperature patterns associated with these modes. Secondly, I will show applications in forcing attribution studies and climate model evaluation. For example, i) winter modulation of the Eastern Atlantic Pattern on decadal to centennial time scales, ii) NAO response to volcanic eruptions during both summer and winter with the NAO phase depending on latitude of eruption, and iii) consistent model biases in the main North Atlantic climate modes of state-of-the art climate models. Finally, I will offer some thoughts on future developments in the topic of “paleo-reanalysis”.
What is the Joint Oslo Seminar (JOS):
- Atmospheric and climate sciences have a stronghold in Oslo among the four institutions University of Oslo, the Meteorological Institute, CICERO and NILU.
- This joint seminar invites renowned international experts to contribute to an informal series of lectures, meant to create interaction with the Oslo atmospheric and climate science community on recent highlights and analysis in the field.
- All seminars will be held on Thursdays (Noon -1pm).