WRF - Developmental Testbed Center

Period – Describes communications for periodic boundary updatesXpose – Describes communications for parallel matrix transposesinclude – Similar to a CPP #include fileThese keywords appear as the first word in a line of the file Registry to define which typeof information is being provided. Following are examples of the more likely Registrytypes that users will need to understandRegistry DimspecThe first set of entries in the Registry is the specifications of the dimensions for the fieldsto be defined. In the example below, three dimensions are defined: i, j, and k. If you doan “ncdump -h” of a WRF file, you will notice that the three primary dimensions arenamed as “west_east”, “south_north”, and “bottom_top”. That information is containedin this example (the example is broken across two lines, but interleaved).# dimspec i 1 standard_domaindimspec j 3 standard_domaindimspec k 2 standard_domain x west_easty south_northz bottom_topThe WRF system has a notion of horizontal and vertical staggering, so the dimensionnames are extended with a “_stag” suffix for the staggered sizes. The list of names in the column must be a single character (for release 3.0.1.1 and prior), and they mustbe unique. This variable is not case specific, so for example “i” is the same as anentry for “I”.Registry State and I1A state variable in WRF is a field that is eligible for IO and communications, and existsfor the duration of the model forecast. The I1 variables (intermediate level one) aretypically thought of as tendency terms, computed during a single model time-step, andthen discarded prior to the next time-step. The space allocation and deallocation for theseI1 variables is automatic (on the stack for the model solver). In this example, forreadability, the column titles and the entries are broken into multiple interleaved lines,with the user entries in a bold font.Some fields have simple entries in the Registry file. The following is a state variable thatis a Fortran type real. The name of the field inside the WRF model is u_gc. It is a threedimension array (igj). It has a single time level, and is staggered in the X and ZWRF-NMM V3: User’s Guide 6-7