Future subsea telecommunication cables could provide in situ measurements of temperature, acceleration and ocean pressure from the ocean bottom. The so-called SMART cables (Science Monitoring And Reliable Telecommunications) will provide real time, high frequency observations on an ocean basin scale. With a life time of over 20 years SMART cables will be used (i) as ground truth for satellites, (ii) to monitor climate change and variability, (iii) to estimate seismic and tsunami hazards as used in early warning systems, and (iv) to improve numerical simulations of ocean dynamics (Howe and Workshop Participants, 2015). 

in the project "SMART cable observations Heuristically Assimilated into global Ocean Simulations (SMART-CHAOS) we use ensemble Kalman filter techniques as implemented in the Parallel Data Assimilation Framework (PDAF; Nerger et al., 2006) to conduct observation system simulation experiments (OSSEs) in order to determine the impact of possible SMART cables on the numerical simulation of ocean dynamics. We perform identical and fraternal twin experiments with the Max-Planck Institute Ocean Model (MPIOM) and the Regional Ocean Modeling System (ROMS). Synthetic observations of ocean bottom pressure  are sampled from MPIOM or, alternatively, from ROMS on a daily basis along possible future SMART cable trajectories. These observations are assimilated with a local Singular Evolutive Interpolated Kalman (SEIK; Pham et al., 1998) filter into MPIOM over a period of one month. Thereby the temporal correlation between the “observed” and the modeled ocean state is increased and the temporal and spatial errors are reduced.