Paleowave

Off to London, guvnor!

 Paleo-ENSO output from IPCC AR5 Models

Paleo-ENSO output from IPCC AR5 Models

Jud Partin and I are off to University College London to attend a workshop entitled Palaeovariability: Data-Model Comparisons. The main aim of the workshop is to facilitate interaction between paleoclimate data gatherers (or "proxy people" such as myself who produce paleoclimate records) and paleoclimate modelers (who use state-of-the-art GCMs to model ancient climates) to figure out novel and optimal methods to actually compare model output to proxy data.

Climate models used to forecast future climates can also be used to simulate past climates based on different climate forcings in the past (such as variations in the Earth's orbit, CO2 etc.) Paleoclimate records of temperature, salinity, rainfall etc. that are generated from proxy data, can be used to test and validate the hindcasts of these climate models. However, there are multiple sources of uncertainty, both from the modeling side and the proxy side, that hinder straightforward comparison between paleoclimate proxy data and paleoclimate model output. For example, the world in models is divided into multiple grids, the size of which defines the spatial resolution of the model. Paleoclimate records obtained from proxy data on the other hand, are generated from one spatial point (eg. a coral, sediment cores, ice cores etc.) What is the best way to compare data and model output? Grid-to-spatial point? Extrapolation? Interpolation? These questions don't have straightforward answers either. Further, there can be multiple age-related uncertainties in the proxy (analytical radiogenic error, bioturbation etc.) that might make you think you are comparing apples and apples from the same time period, when they are actually apples belonging to totally different eras. Most importantly, how well can different climate models simulate climates in a particular region/time and how well can different proxies actually reconstruct climatic parameters?

Well, I hope to gain some insights into all these questions and more, during my time in London! I will be talking about interpreting individual foraminiferal analyses data and how best to reconcile them with model output. My talk is entitled: Paleoceanographic reconstructions using individual foraminifera in the tropical Pacific: Records of annual cycle or ENSO variability? Jud will be bringing his tropical paleoclimate expertise to the table with a talk entitled Tropical Climate Variability in the Western Pacific on Sub-annual to Orbital Timescales. All in all, I'm looking forward to a great week in London, guvnor!