The following maps show the geoghraphic distribution of matchups that pass the initial filters and cloud trees. That is, the matchups shown are the ones used for algorithm coefficient estimation.

• Red circles indicate NDBC moored buoys
• Green diamonds indicate Japanese moored buoys
• Blue squares indicate moored TOGA/TAO buoys
• Yellow triangles indicate UK moored buoys
• Purple small dots indicate drifiting MEDS buoys
• Grey small dots indicate AOML drifting buoys
• Yellow dots indicate NATO drifting buoys