- Shaped by: Christoph, Magdalena, Till - Appetite (FTEs, weeks): - Developers: ## Problem Some fields live at the center, some live on the interface of the vertical, so two different vertical dimensions. Usually center fields have n levels, interface fields n+1 levels. Currently we are not differentiating between center and interface fields, but have workarounds in place in order for the index computations to work out. ## Obervations A staggered grid concept already exists in gt4py-cartesian, the design could be similar * In ICON there exist interpolation coefficients between full and half dimensions, as gt4py sparse type they would be something like `Field[[KFull, KFull2KHalfDim], float]` ## Appetite <!-- Explain how much time we want to spend and how that constrains the solution --> ## Solution Introduce two vertical dimensions and mapping functionality to each other similar to the C, E, V concepts and `neighbor_sum` in the horizontal * Similar to the horizontal case, there should be type errors when directly assigning a full k field to a half k field, or vice versa. ## Steps * Develop concept of mapping between full and half dimensions * Outline implementation details in field view and ITIR ## Rabbit holes <!-- Details about the solution worth calling out to avoid problems --> ## No-gos <!-- Anything specifically excluded from the concept: functionality or use cases we intentionally aren’t covering to fit the ## appetite or make the problem tractable -->