Mapping information pathways of the Asian monsoon with pacemaker simulations

The Asian monsoon is a dominant source of predictability in Northern summer on subseasonal to seasonal scales. We better understand this predictability by mapping information pathways using simple and familiar, yet powerful, Newtonian relaxation (nudging) techniques. Through a systematic set of model experiments, we nudge the Community Atmosphere Model (CAM5) over the South Asia in selected regions, scales, fields, processes, and time intervals, as a tracer of information flow. We then detect this realism at other locations, scales, and lead times via correlations with observations (‘skill' measures) to show signal propagation pathways that form the basis for predictability.