Task PosVal

The task PosVal is used to validate both single-run (compatible code versions 8.x) and ensemble-based deterministic and/or probabilistic outputs against various types of gridded and scattered observation datasets. Observation datasets include satellite-based observations and quantitative retrievals (to validate against cloud column mass), deposit isopach/isopleth maps, and point-wise deposit observations (to validate against deposit thickness or mass load). In all cases, this model task reads the required files, interpolates model and observations into the same grid and computes a series of categorical and quantitative validation metrics that are detailed in the following Section. This model validation task inherits the model domain decomposition structure and, consequently, all metrics are first computed (in parallel) over each spatial sub-domain and then gathered and added to get global results over the whole computational domain.