IMAGe Brown Bag Seminar - Spatio-Temporal Climate Reconstructions of the Last Deglaciation

09/20/2017 - 12:00pm to 1:00pm
ML - 680 Tower B - Penthouse

Spatio-Temporal Climate Reconstructions of the Last Deglaciation

Nils Weitzel

Meteorological Institute of the University of Bonn

Spatio-temporal reconstructions of past climate are important to understand the large scale behavior of the climate system and the sensitivity to forcing changes. Unfortunately, they are subject to large uncertainties, have to deal with a complex proxy-climate structure, and a physically reasonable interpolation between the sparse proxy observations is difficult.

I will present a Bayesian hierarchical model to reconstruct the spatio-temporal temperature evolution during the last deglaciation on continental to hemispheric domains. Due to limited availability and resolution of proxy data the focus is on centennial to millennial scale variations. The statistical model has to deal with non-stationarity behavior in space and time and must be
able to reconstruct gradual as well as abrupt climate changes. To test the skill of the model, I use pseudo-proxy experiments with the CCSM3 Trace21K simulation of the last deglaciation.

In the final part of the talk, I look at the physical interpretation of the model parameters and how the framework can be extended to a simple physically motivated stochastic climate model.  Using this extended model, it is also possible to include additional information like reconstructions of external forcings.

 

Wednesday, September 20th, 2017

12:00pm – 1:00pm

Mesa Lab, 680 Tower B - Penthouse

(Bring your lunch)