Decadal variability in historical simulations by coupled climate models in CMIP5

Climate variability beyond interannual time scales has not been well explored by coupled climate models because of relatively poor simulations and shorter observational record to verify its robustness. However, a newly available historical data assimilation products such as 20CR, newly compiled surface observation datasets such as CRU_TS3.2 and GPCC, paleoclimate records, and improved simulation by coupled climate models provide a new opportunity. In this study, we'll evaluate how well fully coupled climate models in CMIP5 simulate a couple of well known decadal/multi-decadal climate variabilities, such as Pacific Decadal Variability (PDV), Atlantic Multi-decadal oscillation (AMO), and decadal component of North Atlantic Oscillation (NAO). Further, we'll use sets of sensitivity experiments with CESM1 to investigate the anthropogenic causes of these decadal variabilities.