Basic research

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Climate change Air - Sea interactions Internal climate variability
East Asian monsoon Climate Modeling Climate Chemistry interactions

Fundamental 

▶ Internal atmospheric variability, also termed “climate noise” , arises from non-linear dynamical processes intrinsic to the atmosphere(Madden, 1976; Schneider and Kinter,1994; Feldstein, 2000; Deser et al., 2010).

 Internal variability is the natural variability of the climate system that occurs in the absence of external forcing (Deser et al., 2010). Although the atmosphere contains little memory beyond a few weeks, it exhibits long-time scale variability characteristic of a random stochastic process. Internal climate variability arises from atmospheric, oceanic, land, and cryospheric processes and their coupled interactions(Kay et al., 2014). 

 Uncertainty in future climate change derives from three main sources: forcing, model response, and internal variability (e.g., Hawkins and Sutton 2009; Tebaldi and Knutti 2007).

 All 30 CESM-LE members use the same model and the same external forcing. Each CESM-LE ensemble member has a unique climate trajectory due to small round-off level differences in their atmospheric initial conditions. (Kay et al., 2014).



Spread of Ensembles

 ▶ Standard deviation of the absolute values of differences between ensemble mean and 30 members. Simply put, the CESM-LE ensemble spread results from internally generated climate variability alone. Standard deviation of the absolute values of differences between ensemble mean and 30 members. Simply put, the CESM-LE ensemble spread results from internally generated climate variability alone.

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