One of the goals of POBEX is to investigate the response of Pacific Boundary physcial and biological systems to future climate. As a first step we have examined the output of several IPCC climate models.

North Pacific Decadal Variability and Climate Change in the IPCC AR4 Models
Furtado J., E. Di Lorenzo, N. Schneider, N. Bond and J. Overland
Journal of Climate, 2010, draft. [ PDF ]

The dynamics of North Pacific decadal variability (NPDV) are explored in 10 coupled climate models used in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC) for both the 20th century climate and under a greenhouse warming scenario. We examine the two dominant oceanic modes of NPDV, the Pacific Decadal Oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO), along with their respective atmospheric forcing patterns associated with variability of the Aleutian Low (AL) and the North Pacific Oscillation (NPO). We find that the decadal modes of ocean/atmosphere variability (e.g. PDO/AL, NPGO/NPO) are spatially consistent with modern observations in most models and show no change during climate change. The frequency content of the PDO and NPGO also show no significant change in future climate. However, most climate models do not adequately reproduce the observed temporal variability in the 20th century, with some failing to capture the low frequency nature of the PDO and the broad frequency band of the NPGO. In the 20th century, we also find that while the dynamics of the model’s PDO are consistent with forcing by the AL variability, the NPGO of the models is not always driven by atmospheric variability associated with NPO as suggested from modern observations. Further analysis also reveals that the NPDV of the IPCC models is mostly independent of the tropics and does not exhibit the observed relationships between the North Pacific modes (e.g. PDO/AL, NPGO/NPO) and the El Niño-Southern Oscillation (ENSO). In contrast with modern observations, the PDO of most models appears as a mode independent of ENSO during the 20th century and the Seasonal Footprinting Mechanism (SFM), whereby the midlatitude NPGO/NPO winter expression leads the tropical ENSO peak in fall, is not captured in the IPCC models, except for the GFDL 2.1 and MIROC-HIRES. These inconsistencies between observed and modeled climate variability of the IPCC models need careful consideration in the context of ensemble approaches to decadal predictions of the North Pacific.