System and method for rapidly merging earth observations with numerical simulations to provide an on-line decision-support tool for ecological forecasting. The output products will be gridded fields that incorporate both climatological variability and real-time observations. The system and method are based upon four elements: 1) a long-term, coupled biological-optical-physical simulation model run, 2) earth observation (EO) time-series (remote sensing), 3) historical in-situ data, and 4) real-time remote sensing data and in-situ observations.