combine Add together two or more fields that are on the same domain; e.g., latent heat flux plus sensible heat flux on a T42 grid with the same land mask communication interval The time interval at which a component model exchanges data with the coupler. concurrent execution When two or more coupled system components are executing at the same time. domain A grid together with a domain mask. domain mask A mask that indicates which grid cells are active or inactive. grid Coordinate arrays without a mask, cell area, decomposition information; e.g., a T42 grid. map Same as "regrid"; move a data field from one domain to another. mask True/false flags associated with a specific grid; e.g., a land mask. merge Take two or more fields of the same type (e.g., land, ocean, and ice surface temperatures), which are all on the same domain (e.g., all on a T42 grid, global domain), and the same number of corresponding cell fractions (fraction of land, ocean, and ice, which together sum to unity), and create one field, e.g., (merged surface temperature) = (ice frac)*(ice T) + (ocn frac)*(ocn T) + (lnd frac)*(lnd T) . regrid Same as "map"; move a data field from one domain to another. sequential execution When two or more coupled system components do not execute at the same time. timestep A model's internal integration increment in time. Note: the Coupler does not know a model's internal timestep, it only knows a model's communication interval.