There are various standard names for x- and y-components of vector quantities. For instance: `sea_water_x_velocity`. The description always states: `"x" indicates a vector component along the grid x-axis, positive with increasing x`. I assume that this description stems from the idea that the computational grid is a simple Cartesian mesh in some coordinate reference system. The attribute name `grid_mapping` also refers to that assumption.
However, in my case the curvilinear grid is not Cartesian in any coordinate system, but the grid may have been created in some local coordinate system (e.g. a UTM zone), so the grid coordinates are stored using `projection_x_coordinate` and `projection_y_coordinate` variables and the grid_mapping describes (via WKT) the relationship between those x/y coordinates and global latitude/longitude. On this curvilinear grid a `sea_water_x_velocity` quantity is stored. How should it be interpreted? As 1. a vector component along a (curvilinear) grid direction (but which one)? 2. a vector component along the `projection_x_coordinate` direction? If 1, how should we interpret the data if it results from an unstructured model without two grid directions? If 2, can we remove the word "grid" from the description `"x" indicates a vector component along the grid x-axis, positive with increasing x`? Best regards, Bert -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/issues/252 This list forwards relevant notifications from Github. It is distinct from [email protected], although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to [email protected].
