12:25 PM - 12:45 PM
★ [MIS28-06] On the comparison of high-temporal resolution data and model simulation in paleoclimate studies
Keywords:paleoclimate modelling, last millennium, Pacific Decadal Oscillation
Proxy data are often compared with model simulations along time axis. While the dating errors in the data may be more easily taken into consideration in this approach, there are many aspects that need to be concerned. It is often unclear what spatial scale that the data represent, and whether that spatial scale is resolved in the model. In addition, it is subjective to the bias in simulated spatial patterns because proxies often locate in the sensitive region to the changes in the climate pattern. More meaningful comparison would be made if spatially integrated reconstruction or the climate index constructed from multiple sites is used. It is often unclear whether the reconstructed climate variation represents internal variability inherent in the climate system or the change forced by the condition external to the climate system (e.g., volcanic eruptions). This is not independent from the spatial-scale issue as the internal variability usually predominates in smaller scales. More meaningful comparison would be made for the externally forced change that is demonstrated by the model ensemble simulation.
We highlight these issues by conceptual examples and Pacific Decadal Oscillation simulated in the last millennial simulations.